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A photoelectrochemical sensor based on nickel hydroxyl-oxide modified n-silicon electrode for hydrogen peroxide detection in an alkaline solution
Biosensors and Bioelectronics 47 (2013) 225–230
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A photoelectrochemical sensor based on nickel hydroxyl-oxide modified n-silicon electrode for hydrogen peroxide detection in an alkaline solution Huaixiang Li n, Wenlong Hao, Jinchao Hu, Hongyan Wu College of Chemistry, Chemical Engineering and Materials Science, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, PR China
art ic l e i nf o
a b s t r a c t
Article history: Received 13 December 2012 Received in revised form 27 February 2013 Accepted 12 March 2013 Available online 22 March 2013
A novel photoelectrochemical hydrogen peroxide (H2O2) sensor was constructed with platinum (Pt) and nickel hydroxyl-oxide (NiOOH) double layers modified n-silicon electrode (NiOOH/Pt/n–n þ -Si). About 40 nm Pt layer and about 100 nm Ni layer were successively coated on the front surface of n–n þ -Si (1 1 1) wafers by vacuum evaporating. A stable layer of NiOOH was formed through oxidation of the Ni layer on the coated silicon wafer by the electrochemical method. The surface of modified electrode was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The NiOOH/Pt/n–n þ -Si electrode has been used for determination of H2O2 with a two-electrode cell in the absence of reference electrode by photocurrent measurement at a zero bias. The photoelectrochemical sensor showed a good linear response to H2O2 concentrations in a range from 1.0 10−5 to 6 10−5 M with a determination limit (S/N¼3) of 2.2 μM. The NiOOH/Pt/ n–n þ -Si electrode exhibited excellent reproducibility and stability. Particularly, the facile measurement requirements made this novel modified electrode promising for the development of outdoor H2O2 sensors. & 2013 Elsevier B.V. All rights reserved.
Keywords: Hydrogen peroxide Nickel hydroxyl-oxide Photoelectrochemical sensor Silicon electrode
1. Introduction Hydrogen peroxide (H2O2) is a reactive oxygen metabolic byproduct that serves as a key regulator for a number of oxidative stress-related states. H2O2 is involved in several biological events and intracellular pathways, which have been linked to several diseases (Yan et al., 2012). Therefore, rapid and accurate determination of hydrogen peroxide (H2O2) is of practical importance in various fields such as food, clinical and environmental analyses (Song et al., 2010). Currently, several analytical techniques for determination of H2O2 have been reported, including visible absorption spectrometer (Rodrigues and Gomes 2010; Xu et al., 2009), spectrofluorometer (Sang et al., 2010), fluorescence probe (Wen et al., 2012; Qian et al., 2012), chemiluminescence (Navas Diaz et al., 1998), electrochemiluminescence (Chovin et al., 2004; Jiao et al., 2008), high performance liquid chromatography (Tarvin et al., 2010), sensors based on injection of the recognition element (Kriz et al., 2001), electrogenerated chemiluminescence (Han et al., 2011) and electrochemical analysis (Yin et al., 2011). Among them, electrochemical analysis has been widely used, due to several advantages that include fast response, high sensitivity and perfect selectivity. However, one common drawback of the electrochemical analysis is the required reference electrode which has been proved to be an impediment for the sensor miniaturization. On the other
n
Corresponding author. Tel.: þ86 531 861 828 31; fax: þ 86 531 861 825 40. E-mail addresses: [email protected], [email protected] (H. Li).
0956-5663/$ - see front matter & 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.bios.2013.03.028
hand, reference electrode can cause more or less contaminants for the accurate measurement. A new photo-electrochemical sensor based on two-electrode system was newly developed by our group; it has been successfully applied to ascorbic acid (Li et al., 2012a). Photo-electrochemistry is mainly used in the field of solar cell and its usage in biosensor is much limited compared with other techniques (Zhang et al., 2013). So it is still necessary to improve the utilization of photoelectrode in the aspect of analytical detection. In our previous studies, Prussian blue and nickel hexacyanoferrate have been successfully applied in the construction of photoelectrochemical H2O2 sensors (Li et al., 2012b, c) but these electrodes suffered from poor long-term stability in alkaline solution. Therefore, the development of new material modified electrodes with excellent catalytic properties to the oxidation of H2O2 in an alkaline solution would be highly beneficial. In the present study, we have improved the photoelectrochemical sensor to detect H2O2 using an n-silicon electrode modified with a platinum (Pt) film and nickel hydroxyl-oxide (NiOOH) layer. The photocurrent response of the modified electrode to H2O2, selectivity and stability of the sensor have been studied in detail.
2. Experimental 2.1. Chemicals and materials N-type, (1 1 1) oriented 3-inched silicon wafers doped with phosphorus heavy (resistivity: 0.003 Ω cm) with 10–13 μm n-type
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epitaxial layer (resistivity: 3–5 Ω cm) were purchased from Semiconductor Materials Factory, Shanghai Nonferrous Metals Institute and referred to as n–n þ -Si. High purity platinum (Pt) and nickel (Ni) wires ( 499.99%) were purchased from Shanghai Chemical Reagent Station. Hydrogen peroxide (H2O2 30% wt) and other reagents were purchased from Tianjin Guangfu Chemical Reagent Company. Unless otherwise stated, the reagents used in the experiment were of analytical grade and used as received without further purification. 2.2. Preparation of modified electrode Nickel hydroxyl-oxide (NiOOH) was formed by electrochemical oxidation of the Ni film on the Pt coated n–n þ -Si electrode in hydroxide (KOH) solution. Before the formation of NiOOH layer, n–n þ -Si wafers were cleaned in hydrogen fluoride (HF 40% wt) solution, rinsed with doubly distilled water and then dried with nitrogen gas. About 40 nm Pt layer and about 100 nm Ni layer were successively coated on the front surface of n–n þ -Si (1 1 1) wafers by a high vacuum evaporating system (DM 220 Shanghai Optical Electron Company, China). In order to increase ohmic contact area, the back of the Si wafers was coated with about 300 nm aluminum (Al) film. The coated wafers were heated in argon atmosphere at 673 K for 40 min and were referred to as Ni/Pt/n–n þ -Si electrodes herein. A copper wire was glued to the Al coated side of the Ni/Pt/n–n þ -Si as the lead-terminal. Limiting a 1.0 cm2 area to contact electrolyte solution, the other part of the Ni/Pt/ n–n þ -Si electrode was covered by epoxy resin for insulation. Cyclic voltammetry (CV) was performed using an LK 2005 electrochemical workstation (Lanlike Company, Tianjin, China) to generate the NiOOH layer in 100 mL of 0.2 M KOH solution at a scan rate of 50 mV s−1 by using Ni/Pt/ n–n þ -Si electrode as the working electrode. A KCl saturated calomel electrode (SCE) was used as the reference electrode and a platinum plate was used as an auxiliary electrode. The electrolyte solution was stirred by bubbling with high purity nitrogen (99.999%) during measurements. Illumination was made from a 50 W bromine tungsten lamp located 20 cm from the working electrode. The electrode was abbreviated as NiOOH/Pt/n–n þ -Si after electrochemical treatment.
by bubbling highly pure nitrogen during the photocurrent measurements.
3. Results and discussion 3.1. Formation of NiOOH layer on Ni/Pt/n–n þ -Si electrode Several studies have been devoted to investigation of the electrochemical behavior of nickel compound electrodes in alkaline solution (Chen et al., 2009; Yang et al., 2007; Suresh Babu et al., 2011). It is confirmed that the anodic oxidation of the nickel electrode in alkaline solution is related to the Ni/Ni(OH)2 and Ni (OH)2/NiOOH redox reactions (Qiao et al., 2009; Nagashree and Ahmed, 2010). So the CV was performed in this work to generate the nickel hydroxide and nickel hydroxyl-oxide layer in 100 mL of 0.2 M KOH solution at a scan rate of 50 mV s−1 by using Ni/Pt/ n– n þ -Si electrode as the working electrode. Fig. 1 presents the CV curves of this process. In the anodic sweep, two oxidation peaks were observed, corresponding to the oxidations of Ni to Ni(OH)2 at 0.09 V and Ni(OH)2 to NiOOH at 0.32 V. In the cathodic sweep, the reduction of NiOOH to Ni(OH)2 took place at 0.06 V. In the following potential cycling, the position of the oxidation peaks remained nearly constant and the position of reduction peak of NiOOH to Ni(OH)2 was negatively shifted gradually to 0.02 V. The oxidation currents of Ni(OH)2 to NiOOH and reduction currents of NiOOH to Ni(OH)2 increased with the increase of cycles. These current changes in the CV cycles were due to the conversion of the crystal structures of nickel hydroxide and nickel hydroxyl-oxide, which is consistent with the work of Yan et al. (2012). 3.2. Characterization of the modified electrode Fig. 2 shows the SEM images of Ni/Pt/n–n þ -Si surface before (A) and after (B) the cyclic voltammograms in 0.2 M KOH solution. It can be seen in Fig. 2 that the surface of modified electrode became slightly rough after the formation of Ni(OH)2 and NiOOH layer and with some etch pits. The transformation from Ni to Ni (OH)2 and NiOOH on the surface of modified electrode was further confirmed by XPS.
2.3. Characteristics of the modified electrode
2.4. Hydrogen peroxide detection
300 Ni(OH)2
NiOOH
5
200 Current density / µA cm-2
The morphology of the modified electrode was observed with a scanning electron microscope (SEM, HITACHI H-800). X-ray photoelectron spectroscopy (XPS) was used to determine film composition on a Perkin-Elmer PHI-5600 system using monochromatic Al Kα radiation (1486.6 eV). The X-ray generator was operated at 250 W (12.5 kV). The specimens were analyzed using a spherical capacitance analyzer (SCA) at an electron take-off angle of 451. The analyzer energy resolution (the energy difference between two recorded data points) was 0.4 eV for survey scans and 0.1 eV for multiplex scans. The peak positions were calibrated against the carbon 1s peak at 284.6 eV (Li et al., 2010).
1
100
0 1
Photocurrent measurements were performed with a home built photoelectrochemical cell (PEC) with two electrode system consisting of the NiOOH/Pt/n–n þ -Si photoelectrode and a counter electrode of stainless steel plate (non-magnetic material quality: 302, ST–13 tweezers, VETUS, Hongkong). A 50 W halogen lamp (about 50 mW cm-2) was used as the illuminating source located about 20 cm from the PEC. The photocurrent responses with time were measured without applied voltage (at a zero bias) on the LK2005 electrochemical working station. All tested solutions were deaerated
-100
5 NiOOH
-200 -0.6
-0.4
Ni(OH)2
0.0 -0.2 0.2 Potential / V vs SCE
0.4
0.6
Fig. 1. The cyclic voltammograms of Ni/Pt/n–n þ -Si in 0.2 M KOH solution for 5 cycles under illumination.
H. Li et al. / Biosensors and Bioelectronics 47 (2013) 225–230
227
Fig. 2. SEM images of Ni/Pt/n–n þ -Si surface before (A) and after (B) the cyclic voltammograms in 0.2 M KOH solution.
1100 1000
1200000 Ni 2p3/2 from NiOOH/Pt/n-n+-Si 855.1
Ni 2p3/2 from Ni/Pt/n-n+-Si 1000000 852.7
900
859.2 800000
700
CPS
CPS
800
600000
600 400000
500 400
200000
300 0 840
845
855 850 Binding energy / eV
860
865
840
850 Binding energy / eV
860
10000 O 1s from NiOOH/Pt/n-n+-Si 531.3
8000
4000
528.9
CPS
6000 533.8
2000
51 6 51 8 52 0 52 2 52 4 52 6 52 8 53 0 53 2 53 4 53 6 53 8 54 0
0
Binding energy / eV þ
Fig. 3. XPS detailed spectra of Ni 2p3/2 (A) from Ni/Pt/n–n -Si, (B) from NiOOH/Pt/n–n þ -Si, and XPS spectra of O 1s (C) from NiOOH/Pt/n–n þ -Si.
In this investigation, the analytical considerations regarding the electrode surface were drawn mainly by comparison with the XPS data obtained with Ni/Pt/ n–n þ -Si electrodes before and after electrochemical treatments. Fig. 3 shows the typical XPS spectra of the Ni 2p3/2 signal from the Ni/Pt/n–n þ -Si electrode and those from the electrode after continuous cycling of potential between −0.5 and 0.5 V (vs SCE) in alkaline solutions. The peak at 852.7 eV binding energy of the Ni 2p3/2 in Fig. 3 (A) can be assigned to Ni
metal (Grosvenor et al., 2006). Fig. 3(B) shows curve fitting of the Ni 2p3/2 XPS signal from the NiOOH/Pt/n–n þ -Si sample, which gives generally two well resolved peaks at 855.1 eV 70.3 and 859.2 eV 70.3 of binding energy assigned to Ni(OH)2 and NiOOH species, respectively (Casella and Contursi, 2013; Muench et al., 2013). Fig. 3(C) shows curve fitting of the O 1s XPS signal from NiOOH/ Pt/n–n þ -Si electrode. Three resolved peaks at 528.9 eV 70.4,
H. Li et al. / Biosensors and Bioelectronics 47 (2013) 225–230
2NiOOH þH2O2-O2 þ 2Ni(OH)2
(2)
At the same time, an equivalent number of photo-generated electrons from the conduction band (CB) of Si has to transfer through outer circuit to the counter electrode (stainless steel), where H2O2 would be reduced: H2O2 þ2e−(CB)-2OH−
(3)
When the photoelectrode is used in aqueous solution without adding H2O2 (only a KOH) the photo-generated electrons could not produce the water decomposition reaction, showing almost zero photocurrent.
20µM H2O2
20µM L-Cysteine
20µM AA
20µM H2O2 20µM Urea
20µM L-Cysteine
20µM Glucose
8
20µM Ascorbic acid
12
20µM Glucose
3.3.2. Selectivity of the NiOOH/Pt/n–n þ -Si electrode The selectivity of the sensor was also evaluated against urea, ascorbic acid, glucose and l-cysteine since they are commonly present in the physiological samples and they pose interference in the analysis of H2O2 in such samples (Annamalai et al. 2012). Fig. 5 shows photocurrent responses of the NiOOH/Pt/n–n þ -Si electrode for them in a deaerated solution of 0.2 M KOH under illumination. The photocurrent responses were obtained by successive injection of (a) 10 μM H2O2, (b) 20 μM urea, (c) 20 μM ascorbic acid, (d) 20 μM glucose, (e) 20 μM l-cysteine, (f) 20 μM H2O2, (g) 20 μM urea, (h) 20 μM ascorbic acid, (i) 20 μM glucose, (j) 20 μM l-cysteine, and (k) 20 μM H2O2. Data were recorded in
4
0 0
200
400
600
800 Time / s
1000
1200
1400
Fig. 5. Photocurrent response of NiOOH/Pt/n–n þ -Si electrode toward successive addition of H2O2 and interlacing addition of urea, ascorbic acid, glucose and l– cysteine, in the solution of 0.2 M KOH at zero bias under stirring and illumination.
16
20 18 16 14 12 10 8 6 4 2 0
14 Photocurrent /µΑ cm−2
Photocurrent /µA cm-2
3.3.1. Photocurrent responses of the NiOOH/Pt/n–n þ -Si electrode toward H2O2 On the basis of the photoelectrochemical principle (Li et al., 2012a), we tried using photocurrent measurements to track the response of H2O2, based on the NiOOH/Pt/n–n þ -Si electrode. Fig. 4 shows the typical photocurrent–time recording obtained at the NiOOH/Pt/n–n þ -Si electrode with a stainless steel plate counter electrode without applied bias (at zero bias). This two electrode system has successfully averted from inconvenient reference electrode. The photocurrent immediately changed after the addition of H2O2 and reached another steady-state current within several seconds. The response photocurrent increased stepwise for successive additions 6 times 1 10−5 M H2O2 into the 0.2 M KOH. From Fig. 4, it can be seen that the photocurrent response time of the sensor to H2O2 is less than 5 s despite no applied voltage. The plot of the photocurrent as a function of H2O2 concentration is shown in Fig. 4(B), which illustrates that the prepared NiOOH/Pt/n–n þ -Si electrodes exhibited a good linear response to H2O2 concentrations in a range from 1 10−5 to 6 10−5 M with a detection limit (S/ N¼3) of 2.2 μM. The regression equation, photocurrent (μA cm−2)¼ 229xþ1.2457, has a correlation coefficient of 0.9951. After Pt film and n-Si being structured into a Schottky junction, the electrons will flow from Si to Pt film until their Fermi levels equal, resulting in an internal electrostatic field. In this process, the energy bands of Si shift upside with its Fermi lever (Li et al., 2012a). When this Pt/Si junction is irradiated, the incident photons induce sublayer Si through the Pt transparent top layer to generate photo-generated electrons and holes. These electrons and holes are then driven by the internal electrostatic field to outer circuit through n þ -Si and the surface of Pt/n-Si, respectively. When the surface of the photoelectrode is coated by Ni(OH)2 and NiOOH layer, the photo-generated holes (h þ ) could induce following reactions:
(1)
20µM Urea
3.3. Results of determination H2O2
Ni(OH)2 þh þ (VB) þOH−-NiOOHþH2O
10µM H2O2
531.3 eV 70.3 and 533.8 eV 71.3 binding energy can tentatively be assigned to O2−, OH−, metal–oxygen species and adsorbed water (Grosvenor et al., 2006; Chen et al., 2010; Payne et al., 2012). Generally the specific assignment of the O 1s contributions is complex and rather ambiguous owing to the partial overlapping of the various oxygen species (Dalavi et al., 2013). Nevertheless, these XPS results support the formation of Ni(OH)2 and NiOOH species on the surface of modified electrode by cycling the potential in 0.2 M KOH solution under illumination.
Phtocurrent /µΑ cm−2
228
12 10 8 6 4 2 0
0
200
400 600 Time / s
800
0.00 0.01 0.02 0.03 0.04 0.05 0.06 H2O2 Concentration / mM
Fig. 4. (A) The photocurrent response of the NiOOH/Pt/n–n þ -Si electrode to successive additions of 10 μM H2O2 to 0.2 M KOH solution at zero bias and (B) the calibration graph derived from the photocurrent–time measurements.
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Table 1 Amperometric sensing of H2O2 using different modified electrodes. Electrode
Applied potential (V)
pH
Detection limit (μM)
Linear rang (mM)
Intermittent usage time (day)
Reference
PAnFca SPGFE/Pt–PdBNCb Pt/Te-microtubes Ni(OH)2/SiNWc PtIr/Nafion/MWCNTd Pt/CNF electrodee NiOOH/Pt/n–nþ -Si
0.56 (SCE) −0.4 (Ag/AgCl) −0.15 (SCE) 0.2 (Ag/AgCl) 0.25 (SCE) 0 0
5 0.69 7 13.7 7.4 7.4 13.3
4 0.87 1.7 3.3 2.5 0.6 2.2
0.004–0.064 0.005–6 0.0017–25 0–5 0.0025–0.075 0.001–0.8 0.01–0.06
— — — 7 40 30 60
Yang and Mu (2005) Niu et al. (2012) Guascito et al. (2011) Yan et al. (2012) Chen et al. (2012) Liu et al. (2011) This work
a
Polyaniline doped with ferrocenesulfonic acid. Screen-printed gold nanofilm electrode/Pt–Pd bimetallic nanoclusters. Ni(OH)2/ silicon nanowire. d Multiwalled carbon nanotubes. e Carbon nanofiber. b c
the absence of reference electrode and without applied voltage between the NiOOH/Pt/n–n þ -Si and the stainless steel counter electrode. The results clearly indicate that apart from a small decrease in photocurrent observed with addition of 20 μM ascorbic acid, other species such as urea, glucose and l-cysteine injections cause no obvious photocurrent fluctuation, showing little interference in the aforementioned H2O2 detection system. 3.3.3. Portability, stability and reproducibility of the NiOOH/pt/n–n þ -Si electrode system A particular advantage of the present photoelectrochemical sensor is its portability. The NiOOH/Pt/n–n þ -Si electrode after 1 month of intermittent usage was integrated with a stainless steel counter in glass container of 100 mL 0.2 M KOH solution into a photoelectrochemical sensor for determination of H2O2. Photocurrent measurement could be performed under natural sunlight illumination by a digital multimeter (FK830L, FUKE). Measurement time lasted from 16:20 to 16:28 (p.m.) on 13th September (a cloudless day in Jinan, northern latitude 36.401 and east longitude 117.001). The photocurrent responses of the aforementioned system with successive injection of 10 μM H2O2 were similar to the results observed in Section 3.3.1, which demonstrated the portability of the present photoelectrochemical sensor. Another advantage of the present NiOOH/Pt/n–n þ -Si electrode is its good long-term stability. The long-term storage stability of the NiOOH/Pt/n–n þ -Si electrode has been studied over 2 months period by monitoring its photocurrent response to 20 μM hydrogen peroxide solution in 0.2 M KOH solution with intermittent usage (every 2–3 days) and being stored in the 0.2 M KOH solution at room temperature. Its photocurrent response was over 90% of its original counterpart after 2 months of usage and storage. This relatively high stability could be attributed to the chemical composition of the NiOOH film and benign measurement conditions, including no reference electrode and no applied voltage. For comparison with other works, the analytical parameters obtained with different H2O2 amperometric sensors are listed in Table 1, including applied potential, pH, detection limit, linear range, and intermittent usage time. The fabrication reproducibility of five electrodes, made independently, showed an acceptable reproducibility with a relative standard deviation (RSD) of 7.4% for the photocurrents determined at a H2O2 concentration of 10 μM. With one sensor, the mean steady state photocurrent was 2.3 μA with a RSD of 4.7% for eight determinations at a H2O2 concentration of 10 μM. 4. Conclusions A novel photoelectron-chemical sensor for the determination of hydrogen peroxide was developed with a platinum and nickel
hydroxyl-oxide double layers modified n-silicon electrode. A key point of this paper, which gave the sensor special properties different from other ones based on three electrode measurement, is using a two electrode cell. In particular, the sensor would work at a zero bias, which provided a portable and simple device for rapid determination of hydrogen peroxide outdoors. With its simplicity, selectivity, and stability, this strategy shows great promise in the photoelectrochemical detection not only for hydrogen peroxide, but also for other species.
Acknowledgments This work was supported by the National Natural Science Foundation of China (No.: 21175084). The authors wish to thank Mr. Sun J.T. and Mr. Shao H.F. for their help in measurements of SEM and XPS. References Annamalai, S.K., Palani, B., Pillai, K.C., 2012. Colloids and Surfaces A: Physicochemical and Engineering Aspects 395, 207–216. Casella, I.G., Contursi, M., 2013. Journal of Electroanalytical Chemistry 692, 80–86. Chen, W., Tang, J., Cheng, H.J., Xia, X.H., 2009. Talanta 80, 539–543. Chen, K.J., Pillai, K.C., Rick, J., Pan, C.J., Wang, S.H., Liu, C.C., Hwang, B.J., 2012. Biosensors and Bioelectronics 33, 120–127. Chen, L.S., Zhou, H.W., Li, H.X., Yu, L., 2010. Science of Advanced Materials 2, 528–533. Chovin, A., Garrigue, P., Sojic, N., 2004. Electrochimica Acta 49, 3751–3757. Dalavi, D.S., Devan, R.S., Patil, R.S., Ma, Y.R., Patil, P.S., 2013. Materials Letters 90, 60–63. Grosvenor, A.P., Biesinger, M.C., Smart, R.St.C., McIntyre, N.S., 2006. Surface Science 600, 1771–1779. Guascito, M.R., Chirizzi, D., Malitesta, C., Mazzotta, E., Siciliano, M., Siciliano, T., Tepore, A., Turco, A., 2011. Biosensors and Bioelectronics 26, 3562–3569. Han, J.H., Jang, J., Kim, B.K., Choi, H.N., Lee, W.Y., 2011. Journal of Electroanalytical Chemistry 660, 101–107. Jiao, T., Leca-Bouvier, B.D., Boullanger, P., Blum, L.J., Girard-Egrot, A.P., 2008. Colloids and Surfaces A: Physicochemical and Enginering Aspects 321, 143–146. Kriz, K., Anderlund, M., Kriz, D., 2001. Biosensors and Bioelectronics 16, 363–369. Li, H., Qi, G., Chen, L., Hao, W., 2012a. Sensors and Actuators B 173, 540–546. Li, H., Ban, Y., Gao, Q., Wei, Q., 2012b. Integrated Ferroelectrics 135, 110–118. Li, H.X., Ban, Y.P., Gao, Q., Wu, H.D., 2012c. Science of Advanced Materials 4, 935–940. Li, H., Lv, Y., Chen, L., Tian, H., Yu, L., Chen, S., 2010. Journal of Materials Science and Engineering 4, 44–50. Liu, Y., Wang, D., Xu, L., Hou, H., You, T., 2011. Biosensors and Bioelectronics 26, 4585–4590. Muench, F., Oezaslan, M., Rauber, M., Kaserer, S., Fuchs, A., Mankel, E., Brötz, J., Strasser, P., Roth, C., Ensinger, W., 2013. Journal of Power Sources 222, 243–252. Nagashree, K.L., Ahmed, M.F., 2010. Journal of Solid State Electrochemistry 14, 2307–2320. Navas Diaz, A., Ramos Peinado, M.C., Torijas Minguez, M.C., 1998. Analytica Chimica Acta 363, 221–227. Niu, X., Chen, C., Zhao, H., Chai, Y., Lan, M., 2012. Biosensors and Bioelectronics 36, 262–266. Payne, B.P., Biesinger, M.C., McIntyre, N.S., 2012. Journal of Electron Spectroscopy and Related Phenomena 185, 159–166. Qian, Y.Y., Xue, L., Hu, D.X., Li, G.P., Jiang, H., 2012. Dyes and Pigments 95, 373–376.
230
H. Li et al. / Biosensors and Bioelectronics 47 (2013) 225–230
Qiao, J., Tang, S., Tian, Y., Shuang, S., Dong, C., Choi, M.M.F., 2009. Sensors and Actuators B 138, 402–407. Rodrigues, J.V., Gomes, C.M., 2010. Free Radical Biology & Medicine 49, 61–66. Sang, Y., Zhang, L., Li, Y.F., Chen, L.Q., Xu, J.L., Huang, C.Z., 2010. Analytica Chimica Acta 659, 224–228. Song, M.J., Hwang, S.W., Whang, D., 2010. Talanta 80, 1648–1652. Suresh Babu, R., Prabhu, P., Sriman Narayanan, S., 2011. Colloids and Surfaces B: Biointerfaces 88, 755–763. Tarvin, M., McCord, B., Mount, K., Sherlach, K., Miller, M.L., 2010. Journal of Chromatography A 1217, 7564–7572.
Wen, T., Qu, F., Li, N.B., Luo, H.Q., 2012. Analytica Chimica Acta 749, 56–62. Xu, G., Li, H., Ma, X., Jia, X., Dong, J., Qian, W., 2009. Biosensors and Bioelectronics 25, 362–367. Yan, Q., Wang, Z., Zhang, J., Peng, H., Chen, X., Hou, H., Liu, C., 2012. Electrochimica Acta 61, 148–153. Yang, M., Jiang, J., Lu, Y., He, Y., Shen, G., Yu, R., 2007. Biomaterials 28, 3408–3417. Yang, Y., Mu, S., 2005. Biosensors and Bioelectronics 21, 74–78. Yin, Z., Wu, J., Yang, Z., 2011. Biosensors and Bioelectronics 26, 1970–1974. Zhang, X., Xu, Y., Zhao, y., Song, W., 2013. Biosensors and Bioelectronics 39, 338–341.
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A photoelectrochemical sensor based on nickel hydroxyl-oxide modified n-silicon electrode for hydrogen peroxide detection in an alkaline solution Huaixiang Li n, Wenlong Hao, Jinchao Hu, Hongyan Wu College of Chemistry, Chemical Engineering and Materials Science, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, PR China
art ic l e i nf o
a b s t r a c t
Article history: Received 13 December 2012 Received in revised form 27 February 2013 Accepted 12 March 2013 Available online 22 March 2013
A novel photoelectrochemical hydrogen peroxide (H2O2) sensor was constructed with platinum (Pt) and nickel hydroxyl-oxide (NiOOH) double layers modified n-silicon electrode (NiOOH/Pt/n–n þ -Si). About 40 nm Pt layer and about 100 nm Ni layer were successively coated on the front surface of n–n þ -Si (1 1 1) wafers by vacuum evaporating. A stable layer of NiOOH was formed through oxidation of the Ni layer on the coated silicon wafer by the electrochemical method. The surface of modified electrode was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The NiOOH/Pt/n–n þ -Si electrode has been used for determination of H2O2 with a two-electrode cell in the absence of reference electrode by photocurrent measurement at a zero bias. The photoelectrochemical sensor showed a good linear response to H2O2 concentrations in a range from 1.0 10−5 to 6 10−5 M with a determination limit (S/N¼3) of 2.2 μM. The NiOOH/Pt/ n–n þ -Si electrode exhibited excellent reproducibility and stability. Particularly, the facile measurement requirements made this novel modified electrode promising for the development of outdoor H2O2 sensors. & 2013 Elsevier B.V. All rights reserved.
Keywords: Hydrogen peroxide Nickel hydroxyl-oxide Photoelectrochemical sensor Silicon electrode
1. Introduction Hydrogen peroxide (H2O2) is a reactive oxygen metabolic byproduct that serves as a key regulator for a number of oxidative stress-related states. H2O2 is involved in several biological events and intracellular pathways, which have been linked to several diseases (Yan et al., 2012). Therefore, rapid and accurate determination of hydrogen peroxide (H2O2) is of practical importance in various fields such as food, clinical and environmental analyses (Song et al., 2010). Currently, several analytical techniques for determination of H2O2 have been reported, including visible absorption spectrometer (Rodrigues and Gomes 2010; Xu et al., 2009), spectrofluorometer (Sang et al., 2010), fluorescence probe (Wen et al., 2012; Qian et al., 2012), chemiluminescence (Navas Diaz et al., 1998), electrochemiluminescence (Chovin et al., 2004; Jiao et al., 2008), high performance liquid chromatography (Tarvin et al., 2010), sensors based on injection of the recognition element (Kriz et al., 2001), electrogenerated chemiluminescence (Han et al., 2011) and electrochemical analysis (Yin et al., 2011). Among them, electrochemical analysis has been widely used, due to several advantages that include fast response, high sensitivity and perfect selectivity. However, one common drawback of the electrochemical analysis is the required reference electrode which has been proved to be an impediment for the sensor miniaturization. On the other
n
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0956-5663/$ - see front matter & 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.bios.2013.03.028
hand, reference electrode can cause more or less contaminants for the accurate measurement. A new photo-electrochemical sensor based on two-electrode system was newly developed by our group; it has been successfully applied to ascorbic acid (Li et al., 2012a). Photo-electrochemistry is mainly used in the field of solar cell and its usage in biosensor is much limited compared with other techniques (Zhang et al., 2013). So it is still necessary to improve the utilization of photoelectrode in the aspect of analytical detection. In our previous studies, Prussian blue and nickel hexacyanoferrate have been successfully applied in the construction of photoelectrochemical H2O2 sensors (Li et al., 2012b, c) but these electrodes suffered from poor long-term stability in alkaline solution. Therefore, the development of new material modified electrodes with excellent catalytic properties to the oxidation of H2O2 in an alkaline solution would be highly beneficial. In the present study, we have improved the photoelectrochemical sensor to detect H2O2 using an n-silicon electrode modified with a platinum (Pt) film and nickel hydroxyl-oxide (NiOOH) layer. The photocurrent response of the modified electrode to H2O2, selectivity and stability of the sensor have been studied in detail.
2. Experimental 2.1. Chemicals and materials N-type, (1 1 1) oriented 3-inched silicon wafers doped with phosphorus heavy (resistivity: 0.003 Ω cm) with 10–13 μm n-type
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epitaxial layer (resistivity: 3–5 Ω cm) were purchased from Semiconductor Materials Factory, Shanghai Nonferrous Metals Institute and referred to as n–n þ -Si. High purity platinum (Pt) and nickel (Ni) wires ( 499.99%) were purchased from Shanghai Chemical Reagent Station. Hydrogen peroxide (H2O2 30% wt) and other reagents were purchased from Tianjin Guangfu Chemical Reagent Company. Unless otherwise stated, the reagents used in the experiment were of analytical grade and used as received without further purification. 2.2. Preparation of modified electrode Nickel hydroxyl-oxide (NiOOH) was formed by electrochemical oxidation of the Ni film on the Pt coated n–n þ -Si electrode in hydroxide (KOH) solution. Before the formation of NiOOH layer, n–n þ -Si wafers were cleaned in hydrogen fluoride (HF 40% wt) solution, rinsed with doubly distilled water and then dried with nitrogen gas. About 40 nm Pt layer and about 100 nm Ni layer were successively coated on the front surface of n–n þ -Si (1 1 1) wafers by a high vacuum evaporating system (DM 220 Shanghai Optical Electron Company, China). In order to increase ohmic contact area, the back of the Si wafers was coated with about 300 nm aluminum (Al) film. The coated wafers were heated in argon atmosphere at 673 K for 40 min and were referred to as Ni/Pt/n–n þ -Si electrodes herein. A copper wire was glued to the Al coated side of the Ni/Pt/n–n þ -Si as the lead-terminal. Limiting a 1.0 cm2 area to contact electrolyte solution, the other part of the Ni/Pt/ n–n þ -Si electrode was covered by epoxy resin for insulation. Cyclic voltammetry (CV) was performed using an LK 2005 electrochemical workstation (Lanlike Company, Tianjin, China) to generate the NiOOH layer in 100 mL of 0.2 M KOH solution at a scan rate of 50 mV s−1 by using Ni/Pt/ n–n þ -Si electrode as the working electrode. A KCl saturated calomel electrode (SCE) was used as the reference electrode and a platinum plate was used as an auxiliary electrode. The electrolyte solution was stirred by bubbling with high purity nitrogen (99.999%) during measurements. Illumination was made from a 50 W bromine tungsten lamp located 20 cm from the working electrode. The electrode was abbreviated as NiOOH/Pt/n–n þ -Si after electrochemical treatment.
by bubbling highly pure nitrogen during the photocurrent measurements.
3. Results and discussion 3.1. Formation of NiOOH layer on Ni/Pt/n–n þ -Si electrode Several studies have been devoted to investigation of the electrochemical behavior of nickel compound electrodes in alkaline solution (Chen et al., 2009; Yang et al., 2007; Suresh Babu et al., 2011). It is confirmed that the anodic oxidation of the nickel electrode in alkaline solution is related to the Ni/Ni(OH)2 and Ni (OH)2/NiOOH redox reactions (Qiao et al., 2009; Nagashree and Ahmed, 2010). So the CV was performed in this work to generate the nickel hydroxide and nickel hydroxyl-oxide layer in 100 mL of 0.2 M KOH solution at a scan rate of 50 mV s−1 by using Ni/Pt/ n– n þ -Si electrode as the working electrode. Fig. 1 presents the CV curves of this process. In the anodic sweep, two oxidation peaks were observed, corresponding to the oxidations of Ni to Ni(OH)2 at 0.09 V and Ni(OH)2 to NiOOH at 0.32 V. In the cathodic sweep, the reduction of NiOOH to Ni(OH)2 took place at 0.06 V. In the following potential cycling, the position of the oxidation peaks remained nearly constant and the position of reduction peak of NiOOH to Ni(OH)2 was negatively shifted gradually to 0.02 V. The oxidation currents of Ni(OH)2 to NiOOH and reduction currents of NiOOH to Ni(OH)2 increased with the increase of cycles. These current changes in the CV cycles were due to the conversion of the crystal structures of nickel hydroxide and nickel hydroxyl-oxide, which is consistent with the work of Yan et al. (2012). 3.2. Characterization of the modified electrode Fig. 2 shows the SEM images of Ni/Pt/n–n þ -Si surface before (A) and after (B) the cyclic voltammograms in 0.2 M KOH solution. It can be seen in Fig. 2 that the surface of modified electrode became slightly rough after the formation of Ni(OH)2 and NiOOH layer and with some etch pits. The transformation from Ni to Ni (OH)2 and NiOOH on the surface of modified electrode was further confirmed by XPS.
2.3. Characteristics of the modified electrode
2.4. Hydrogen peroxide detection
300 Ni(OH)2
NiOOH
5
200 Current density / µA cm-2
The morphology of the modified electrode was observed with a scanning electron microscope (SEM, HITACHI H-800). X-ray photoelectron spectroscopy (XPS) was used to determine film composition on a Perkin-Elmer PHI-5600 system using monochromatic Al Kα radiation (1486.6 eV). The X-ray generator was operated at 250 W (12.5 kV). The specimens were analyzed using a spherical capacitance analyzer (SCA) at an electron take-off angle of 451. The analyzer energy resolution (the energy difference between two recorded data points) was 0.4 eV for survey scans and 0.1 eV for multiplex scans. The peak positions were calibrated against the carbon 1s peak at 284.6 eV (Li et al., 2010).
1
100
0 1
Photocurrent measurements were performed with a home built photoelectrochemical cell (PEC) with two electrode system consisting of the NiOOH/Pt/n–n þ -Si photoelectrode and a counter electrode of stainless steel plate (non-magnetic material quality: 302, ST–13 tweezers, VETUS, Hongkong). A 50 W halogen lamp (about 50 mW cm-2) was used as the illuminating source located about 20 cm from the PEC. The photocurrent responses with time were measured without applied voltage (at a zero bias) on the LK2005 electrochemical working station. All tested solutions were deaerated
-100
5 NiOOH
-200 -0.6
-0.4
Ni(OH)2
0.0 -0.2 0.2 Potential / V vs SCE
0.4
0.6
Fig. 1. The cyclic voltammograms of Ni/Pt/n–n þ -Si in 0.2 M KOH solution for 5 cycles under illumination.
H. Li et al. / Biosensors and Bioelectronics 47 (2013) 225–230
227
Fig. 2. SEM images of Ni/Pt/n–n þ -Si surface before (A) and after (B) the cyclic voltammograms in 0.2 M KOH solution.
1100 1000
1200000 Ni 2p3/2 from NiOOH/Pt/n-n+-Si 855.1
Ni 2p3/2 from Ni/Pt/n-n+-Si 1000000 852.7
900
859.2 800000
700
CPS
CPS
800
600000
600 400000
500 400
200000
300 0 840
845
855 850 Binding energy / eV
860
865
840
850 Binding energy / eV
860
10000 O 1s from NiOOH/Pt/n-n+-Si 531.3
8000
4000
528.9
CPS
6000 533.8
2000
51 6 51 8 52 0 52 2 52 4 52 6 52 8 53 0 53 2 53 4 53 6 53 8 54 0
0
Binding energy / eV þ
Fig. 3. XPS detailed spectra of Ni 2p3/2 (A) from Ni/Pt/n–n -Si, (B) from NiOOH/Pt/n–n þ -Si, and XPS spectra of O 1s (C) from NiOOH/Pt/n–n þ -Si.
In this investigation, the analytical considerations regarding the electrode surface were drawn mainly by comparison with the XPS data obtained with Ni/Pt/ n–n þ -Si electrodes before and after electrochemical treatments. Fig. 3 shows the typical XPS spectra of the Ni 2p3/2 signal from the Ni/Pt/n–n þ -Si electrode and those from the electrode after continuous cycling of potential between −0.5 and 0.5 V (vs SCE) in alkaline solutions. The peak at 852.7 eV binding energy of the Ni 2p3/2 in Fig. 3 (A) can be assigned to Ni
metal (Grosvenor et al., 2006). Fig. 3(B) shows curve fitting of the Ni 2p3/2 XPS signal from the NiOOH/Pt/n–n þ -Si sample, which gives generally two well resolved peaks at 855.1 eV 70.3 and 859.2 eV 70.3 of binding energy assigned to Ni(OH)2 and NiOOH species, respectively (Casella and Contursi, 2013; Muench et al., 2013). Fig. 3(C) shows curve fitting of the O 1s XPS signal from NiOOH/ Pt/n–n þ -Si electrode. Three resolved peaks at 528.9 eV 70.4,
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2NiOOH þH2O2-O2 þ 2Ni(OH)2
(2)
At the same time, an equivalent number of photo-generated electrons from the conduction band (CB) of Si has to transfer through outer circuit to the counter electrode (stainless steel), where H2O2 would be reduced: H2O2 þ2e−(CB)-2OH−
(3)
When the photoelectrode is used in aqueous solution without adding H2O2 (only a KOH) the photo-generated electrons could not produce the water decomposition reaction, showing almost zero photocurrent.
20µM H2O2
20µM L-Cysteine
20µM AA
20µM H2O2 20µM Urea
20µM L-Cysteine
20µM Glucose
8
20µM Ascorbic acid
12
20µM Glucose
3.3.2. Selectivity of the NiOOH/Pt/n–n þ -Si electrode The selectivity of the sensor was also evaluated against urea, ascorbic acid, glucose and l-cysteine since they are commonly present in the physiological samples and they pose interference in the analysis of H2O2 in such samples (Annamalai et al. 2012). Fig. 5 shows photocurrent responses of the NiOOH/Pt/n–n þ -Si electrode for them in a deaerated solution of 0.2 M KOH under illumination. The photocurrent responses were obtained by successive injection of (a) 10 μM H2O2, (b) 20 μM urea, (c) 20 μM ascorbic acid, (d) 20 μM glucose, (e) 20 μM l-cysteine, (f) 20 μM H2O2, (g) 20 μM urea, (h) 20 μM ascorbic acid, (i) 20 μM glucose, (j) 20 μM l-cysteine, and (k) 20 μM H2O2. Data were recorded in
4
0 0
200
400
600
800 Time / s
1000
1200
1400
Fig. 5. Photocurrent response of NiOOH/Pt/n–n þ -Si electrode toward successive addition of H2O2 and interlacing addition of urea, ascorbic acid, glucose and l– cysteine, in the solution of 0.2 M KOH at zero bias under stirring and illumination.
16
20 18 16 14 12 10 8 6 4 2 0
14 Photocurrent /µΑ cm−2
Photocurrent /µA cm-2
3.3.1. Photocurrent responses of the NiOOH/Pt/n–n þ -Si electrode toward H2O2 On the basis of the photoelectrochemical principle (Li et al., 2012a), we tried using photocurrent measurements to track the response of H2O2, based on the NiOOH/Pt/n–n þ -Si electrode. Fig. 4 shows the typical photocurrent–time recording obtained at the NiOOH/Pt/n–n þ -Si electrode with a stainless steel plate counter electrode without applied bias (at zero bias). This two electrode system has successfully averted from inconvenient reference electrode. The photocurrent immediately changed after the addition of H2O2 and reached another steady-state current within several seconds. The response photocurrent increased stepwise for successive additions 6 times 1 10−5 M H2O2 into the 0.2 M KOH. From Fig. 4, it can be seen that the photocurrent response time of the sensor to H2O2 is less than 5 s despite no applied voltage. The plot of the photocurrent as a function of H2O2 concentration is shown in Fig. 4(B), which illustrates that the prepared NiOOH/Pt/n–n þ -Si electrodes exhibited a good linear response to H2O2 concentrations in a range from 1 10−5 to 6 10−5 M with a detection limit (S/ N¼3) of 2.2 μM. The regression equation, photocurrent (μA cm−2)¼ 229xþ1.2457, has a correlation coefficient of 0.9951. After Pt film and n-Si being structured into a Schottky junction, the electrons will flow from Si to Pt film until their Fermi levels equal, resulting in an internal electrostatic field. In this process, the energy bands of Si shift upside with its Fermi lever (Li et al., 2012a). When this Pt/Si junction is irradiated, the incident photons induce sublayer Si through the Pt transparent top layer to generate photo-generated electrons and holes. These electrons and holes are then driven by the internal electrostatic field to outer circuit through n þ -Si and the surface of Pt/n-Si, respectively. When the surface of the photoelectrode is coated by Ni(OH)2 and NiOOH layer, the photo-generated holes (h þ ) could induce following reactions:
(1)
20µM Urea
3.3. Results of determination H2O2
Ni(OH)2 þh þ (VB) þOH−-NiOOHþH2O
10µM H2O2
531.3 eV 70.3 and 533.8 eV 71.3 binding energy can tentatively be assigned to O2−, OH−, metal–oxygen species and adsorbed water (Grosvenor et al., 2006; Chen et al., 2010; Payne et al., 2012). Generally the specific assignment of the O 1s contributions is complex and rather ambiguous owing to the partial overlapping of the various oxygen species (Dalavi et al., 2013). Nevertheless, these XPS results support the formation of Ni(OH)2 and NiOOH species on the surface of modified electrode by cycling the potential in 0.2 M KOH solution under illumination.
Phtocurrent /µΑ cm−2
228
12 10 8 6 4 2 0
0
200
400 600 Time / s
800
0.00 0.01 0.02 0.03 0.04 0.05 0.06 H2O2 Concentration / mM
Fig. 4. (A) The photocurrent response of the NiOOH/Pt/n–n þ -Si electrode to successive additions of 10 μM H2O2 to 0.2 M KOH solution at zero bias and (B) the calibration graph derived from the photocurrent–time measurements.
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Table 1 Amperometric sensing of H2O2 using different modified electrodes. Electrode
Applied potential (V)
pH
Detection limit (μM)
Linear rang (mM)
Intermittent usage time (day)
Reference
PAnFca SPGFE/Pt–PdBNCb Pt/Te-microtubes Ni(OH)2/SiNWc PtIr/Nafion/MWCNTd Pt/CNF electrodee NiOOH/Pt/n–nþ -Si
0.56 (SCE) −0.4 (Ag/AgCl) −0.15 (SCE) 0.2 (Ag/AgCl) 0.25 (SCE) 0 0
5 0.69 7 13.7 7.4 7.4 13.3
4 0.87 1.7 3.3 2.5 0.6 2.2
0.004–0.064 0.005–6 0.0017–25 0–5 0.0025–0.075 0.001–0.8 0.01–0.06
— — — 7 40 30 60
Yang and Mu (2005) Niu et al. (2012) Guascito et al. (2011) Yan et al. (2012) Chen et al. (2012) Liu et al. (2011) This work
a
Polyaniline doped with ferrocenesulfonic acid. Screen-printed gold nanofilm electrode/Pt–Pd bimetallic nanoclusters. Ni(OH)2/ silicon nanowire. d Multiwalled carbon nanotubes. e Carbon nanofiber. b c
the absence of reference electrode and without applied voltage between the NiOOH/Pt/n–n þ -Si and the stainless steel counter electrode. The results clearly indicate that apart from a small decrease in photocurrent observed with addition of 20 μM ascorbic acid, other species such as urea, glucose and l-cysteine injections cause no obvious photocurrent fluctuation, showing little interference in the aforementioned H2O2 detection system. 3.3.3. Portability, stability and reproducibility of the NiOOH/pt/n–n þ -Si electrode system A particular advantage of the present photoelectrochemical sensor is its portability. The NiOOH/Pt/n–n þ -Si electrode after 1 month of intermittent usage was integrated with a stainless steel counter in glass container of 100 mL 0.2 M KOH solution into a photoelectrochemical sensor for determination of H2O2. Photocurrent measurement could be performed under natural sunlight illumination by a digital multimeter (FK830L, FUKE). Measurement time lasted from 16:20 to 16:28 (p.m.) on 13th September (a cloudless day in Jinan, northern latitude 36.401 and east longitude 117.001). The photocurrent responses of the aforementioned system with successive injection of 10 μM H2O2 were similar to the results observed in Section 3.3.1, which demonstrated the portability of the present photoelectrochemical sensor. Another advantage of the present NiOOH/Pt/n–n þ -Si electrode is its good long-term stability. The long-term storage stability of the NiOOH/Pt/n–n þ -Si electrode has been studied over 2 months period by monitoring its photocurrent response to 20 μM hydrogen peroxide solution in 0.2 M KOH solution with intermittent usage (every 2–3 days) and being stored in the 0.2 M KOH solution at room temperature. Its photocurrent response was over 90% of its original counterpart after 2 months of usage and storage. This relatively high stability could be attributed to the chemical composition of the NiOOH film and benign measurement conditions, including no reference electrode and no applied voltage. For comparison with other works, the analytical parameters obtained with different H2O2 amperometric sensors are listed in Table 1, including applied potential, pH, detection limit, linear range, and intermittent usage time. The fabrication reproducibility of five electrodes, made independently, showed an acceptable reproducibility with a relative standard deviation (RSD) of 7.4% for the photocurrents determined at a H2O2 concentration of 10 μM. With one sensor, the mean steady state photocurrent was 2.3 μA with a RSD of 4.7% for eight determinations at a H2O2 concentration of 10 μM. 4. Conclusions A novel photoelectron-chemical sensor for the determination of hydrogen peroxide was developed with a platinum and nickel
hydroxyl-oxide double layers modified n-silicon electrode. A key point of this paper, which gave the sensor special properties different from other ones based on three electrode measurement, is using a two electrode cell. In particular, the sensor would work at a zero bias, which provided a portable and simple device for rapid determination of hydrogen peroxide outdoors. With its simplicity, selectivity, and stability, this strategy shows great promise in the photoelectrochemical detection not only for hydrogen peroxide, but also for other species.
Acknowledgments This work was supported by the National Natural Science Foundation of China (No.: 21175084). The authors wish to thank Mr. Sun J.T. and Mr. Shao H.F. for their help in measurements of SEM and XPS. References Annamalai, S.K., Palani, B., Pillai, K.C., 2012. Colloids and Surfaces A: Physicochemical and Engineering Aspects 395, 207–216. Casella, I.G., Contursi, M., 2013. Journal of Electroanalytical Chemistry 692, 80–86. Chen, W., Tang, J., Cheng, H.J., Xia, X.H., 2009. Talanta 80, 539–543. Chen, K.J., Pillai, K.C., Rick, J., Pan, C.J., Wang, S.H., Liu, C.C., Hwang, B.J., 2012. Biosensors and Bioelectronics 33, 120–127. Chen, L.S., Zhou, H.W., Li, H.X., Yu, L., 2010. Science of Advanced Materials 2, 528–533. Chovin, A., Garrigue, P., Sojic, N., 2004. Electrochimica Acta 49, 3751–3757. Dalavi, D.S., Devan, R.S., Patil, R.S., Ma, Y.R., Patil, P.S., 2013. Materials Letters 90, 60–63. Grosvenor, A.P., Biesinger, M.C., Smart, R.St.C., McIntyre, N.S., 2006. Surface Science 600, 1771–1779. Guascito, M.R., Chirizzi, D., Malitesta, C., Mazzotta, E., Siciliano, M., Siciliano, T., Tepore, A., Turco, A., 2011. Biosensors and Bioelectronics 26, 3562–3569. Han, J.H., Jang, J., Kim, B.K., Choi, H.N., Lee, W.Y., 2011. Journal of Electroanalytical Chemistry 660, 101–107. Jiao, T., Leca-Bouvier, B.D., Boullanger, P., Blum, L.J., Girard-Egrot, A.P., 2008. Colloids and Surfaces A: Physicochemical and Enginering Aspects 321, 143–146. Kriz, K., Anderlund, M., Kriz, D., 2001. Biosensors and Bioelectronics 16, 363–369. Li, H., Qi, G., Chen, L., Hao, W., 2012a. Sensors and Actuators B 173, 540–546. Li, H., Ban, Y., Gao, Q., Wei, Q., 2012b. Integrated Ferroelectrics 135, 110–118. Li, H.X., Ban, Y.P., Gao, Q., Wu, H.D., 2012c. Science of Advanced Materials 4, 935–940. Li, H., Lv, Y., Chen, L., Tian, H., Yu, L., Chen, S., 2010. Journal of Materials Science and Engineering 4, 44–50. Liu, Y., Wang, D., Xu, L., Hou, H., You, T., 2011. Biosensors and Bioelectronics 26, 4585–4590. Muench, F., Oezaslan, M., Rauber, M., Kaserer, S., Fuchs, A., Mankel, E., Brötz, J., Strasser, P., Roth, C., Ensinger, W., 2013. Journal of Power Sources 222, 243–252. Nagashree, K.L., Ahmed, M.F., 2010. Journal of Solid State Electrochemistry 14, 2307–2320. Navas Diaz, A., Ramos Peinado, M.C., Torijas Minguez, M.C., 1998. Analytica Chimica Acta 363, 221–227. Niu, X., Chen, C., Zhao, H., Chai, Y., Lan, M., 2012. Biosensors and Bioelectronics 36, 262–266. Payne, B.P., Biesinger, M.C., McIntyre, N.S., 2012. Journal of Electron Spectroscopy and Related Phenomena 185, 159–166. Qian, Y.Y., Xue, L., Hu, D.X., Li, G.P., Jiang, H., 2012. Dyes and Pigments 95, 373–376.
230
H. Li et al. / Biosensors and Bioelectronics 47 (2013) 225–230
Qiao, J., Tang, S., Tian, Y., Shuang, S., Dong, C., Choi, M.M.F., 2009. Sensors and Actuators B 138, 402–407. Rodrigues, J.V., Gomes, C.M., 2010. Free Radical Biology & Medicine 49, 61–66. Sang, Y., Zhang, L., Li, Y.F., Chen, L.Q., Xu, J.L., Huang, C.Z., 2010. Analytica Chimica Acta 659, 224–228. Song, M.J., Hwang, S.W., Whang, D., 2010. Talanta 80, 1648–1652. Suresh Babu, R., Prabhu, P., Sriman Narayanan, S., 2011. Colloids and Surfaces B: Biointerfaces 88, 755–763. Tarvin, M., McCord, B., Mount, K., Sherlach, K., Miller, M.L., 2010. Journal of Chromatography A 1217, 7564–7572.
Wen, T., Qu, F., Li, N.B., Luo, H.Q., 2012. Analytica Chimica Acta 749, 56–62. Xu, G., Li, H., Ma, X., Jia, X., Dong, J., Qian, W., 2009. Biosensors and Bioelectronics 25, 362–367. Yan, Q., Wang, Z., Zhang, J., Peng, H., Chen, X., Hou, H., Liu, C., 2012. Electrochimica Acta 61, 148–153. Yang, M., Jiang, J., Lu, Y., He, Y., Shen, G., Yu, R., 2007. Biomaterials 28, 3408–3417. Yang, Y., Mu, S., 2005. Biosensors and Bioelectronics 21, 74–78. Yin, Z., Wu, J., Yang, Z., 2011. Biosensors and Bioelectronics 26, 1970–1974. Zhang, X., Xu, Y., Zhao, y., Song, W., 2013. Biosensors and Bioelectronics 39, 338–341.