Preparation of cellophane-based substrate and its SERS performance on the detection of CV and acetamiprid

Accepted Manuscript Preparation of cellophane-based substrate and its SERS performance on the detection of CV and acetamiprid

Wenxian Wei, Qingli Huang PII: DOI: Reference:

S1386-1425(17)30972-1 doi:10.1016/j.saa.2017.11.062 SAA 15644

To appear in:

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

Received date: Revised date: Accepted date:

27 August 2017 28 November 2017 29 November 2017

Please cite this article as: Wenxian Wei, Qingli Huang , Preparation of cellophane-based substrate and its SERS performance on the detection of CV and acetamiprid. The address for the corresponding author was captured as affiliation for all authors. Please check if appropriate. Saa(2017), doi:10.1016/j.saa.2017.11.062

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT Preparation of cellophane-based substrate and its SERS performance on the detection of CV and acetamiprid Wenxian Wei*a, Qingli Huangb a. Testing center, Yangzhou University, Yangzhou city, Jiangsu 225009, China

City, Jiangsu 221004, China

PT

b. Research Facility Center for Morphology of Xuzhou Medical University, Xuzhou

Abstract: Cellophane was taken as platform to fabricate a new SERS substrate via

RI

silver mirror action. From Raman spectra, it can be found that the Raman signal of

SC

Ag-coated cellophane has little influence on the detection of analytes molecules. Raman mapping analysis showed that the cellophane-based SERS substrate has good

NU

uniformity. By using the Ag-coated cellophane, 10-6~10-9 M crystal violet (CV) could be detected by this substrate and the reproducibility of the substrate was also involved.

MA

Acetamiprid was also detected via Ag-coated cellophane. The result showed that cellophane is suitable to be taken as platform for preparation of SERS substrates.

1. Introduction

PT E

D

Keywords: cellophane, silver nanoparticles, SERS, crystal violet, acetamiprid

Recently, a range of analytical techniques combined with several types of sensor

CE

platforms have being used to detect chemical and biological hazardous molecules [1]. Surface-enhanced Raman spectroscopy (SERS) is a promising technique for the trace

AC

detection and analysis of hazards because of its good sensitivity and spectral selectivity [2-4]. Nowadays, SERS technique has made great progress in fields such as food safety [5, 6], explosives [7] and environment monitoring [8, 9]. The fabrication of the SERS substrate is one of the key processes for SERS analysis [10]. As well known, cellulosic matrices can be taken as an effective platform due to their abundance in nature, can be taken as an effective platform has been highlighted due to their abundance in nature, and being a biodegradable and biocompatible polymer [11]. Recently, many kinds of cellulosic matrices such as filter paper [12-17], sulfate

ACCEPTED MANUSCRIPT paper [18], bacterial cellulose [19] and cotton [20-22] have been used and various methods have been developed to fabricate metal nanoparticles onto the cellulosic matrices [23-27]. However, on the one hand, the SERS intensity with maximum difference could be close to 80% because of the roughness of the paper substrates. On the other hand, the uniformity caused by the roughness of the substrates will lead to

PT

poor accuracy of trace amounts of molecules [28]. As we known, cellophane is a kind of regenerated cellulose and has different

RI

crystallization from the paper. Cellophane is transparent, smooth, not hydrophilic and environment-friendly. To our best knowledge, cellophane has not been reported by

SC

using as SERS substrate. In this work, Ag nanoparticles were fabricated onto fibers of cellophane and its SERS activity was analyzed using crystal violet (CV) and

NU

acetamiprid as probe molecules. CV and acetamiprid which is a kind of commonly used pesticides were used because they are toxic and disturb the ecological system [29,

MA

30]. It is found that the established cellophane-based SERS substrate is suitable for the detection of trace amounts of hazardous molecules due to its low cost, easy

D

operation, good sensitivity and uniformity.

PT E

2. Experimental 2.1 Materials

CE

All the chemical reagents used in this work, including silver nitrate (AgNO3), glucose, ammonium hydroxide (NH3·H2O), crystal violet (CV) and acetamiprid are

AC

analytically pure, and all the chemical reagents were used as received without further purification. Cellophane (CP) was obtained from Shanghai Duoxi Biological Technology Co.,Ltd. (Shanghai, China). Deionized water was used for all procedures. 2.2 Characterization Scanning electron microscope (SEM) images were obtained using a HITACHI S−4800 microscope (Japan). The phase purity of the products was characterized by X-ray diffraction (XRD, German Bruker AXSD8 ADVANCE X-ray diffractometer) using an X-ray diffractometer with Cu KR radiation (λ= 1.5418Å). The

ACCEPTED MANUSCRIPT ultraviolet-visible (UV-vis) diffuse reflectance spectra were obtained on an America Varian Cary 5000 spectrophotometer. Raman spectra were measured using a Britain Renishaw inVia Raman spectrometer at room temperature in the range of 500–1800 cm−1. CV and acetamiprid molecular was detected by using 532 nm and 785 nm laser respectively. The SERS mapping measurements were performed on a Thermo Fisher

PT

Scientific DXRxi Raman imaging microscope (USA) by using 532 nm laser. 2.3 Preparation of the cellophane-based substrate

RI

Cellophane was rinsed by deionized water and ethanol before used. The

SC

fabrication process is identical as reported in [24] except glucose was used as reducing agent and cellophane was chosen instead of filter paper. In brief, 2%

NU

NH3·H2O was added into the 10 mL 10 mM AgNO3 solution to form Ag(NH3)2+ and cellophane was vertically immersed into the solution for a few minutes. After that, 10

MA

mL 100 mM glucose solution were added into the Ag(NH3)2+ solution and the silver mirror reaction happened at room temperature. After the reaction was finished, the

D

cellophane-based substrate was taken out from the solution and rinsed with distilled

PT E

water and ethanol subsequently and then dried in air. 2.4 Sample preparation for SERS detection The cellophane-based substrate was fixed on the surface of the glass slide by

CE

double-sided adhesive tape and 10 μL CV (or acetamiorid) with various

AC

concentrations were dropped onto surfaces of the CP and after about 20 min Raman signals were collected. 3. Results and Discussion 3.1 Characterization of cellophane and Ag-coated CP Cellophane has large numbers of hydroxyl and ether groups which can act as active sites for metal ions adsorption. Therefore, Ag ions can be reduced to silver nanoparticles when proper reagent and conditions are provided [11]. Fig.1(a) shows the photograph of the cellophane before and after silver mirror

ACCEPTED MANUSCRIPT reaction. It can be found that the transparent cellophane turned dark brown after the silver mirror reaction, which meant Ag was generated on the surface of cellophane. Fig.1(b) and Fig.1(c) shows SEM images of cellophane before and after the impregnation with Ag. Compared the changes in the morphology, the surface of cellophane became rough because of depositing Ag nanoparticles, which is consistent

PT

with the EDS result shown in Fig.1(d). UV-Vis and XRD analysis were also performed and the results were shown in

RI

Fig.2 (a) and (b).

From the UV–Vis spectra (Fig. 2(a)), a maximum absorption peak at 410 nm can

SC

be observed after Ag was deposited on cellophane. This optical absorption corresponds to the absorption of the localized surface plasmon resonance of Ag NPs.

NU

XRD analysis was also used to characterize the phase structure of Ag in Ag-coated CP. According to Fig.2(b), except diffraction peaks of fibers from cellophane, four distinct

MA

peaks with 2θ values of 38.2°, 44.3°, 64.7° and 77.4°(marked with▼) which were attributed to the (111), (200), (220) and (311) crystalline planes of Ag can be

D

observed.

PT E

Therefore, it can be concluded that crystallized Ag nanoparticles were formed on the fibers of cellophane.

CE

3.2 Uniformity, sensitivity and reproducibility of the CP substrate Fig.3 (a) and (b) are the Raman spectra of Ag-coated CP and 10-3 M CV detected

AC

by bare cellophane. As seen in Fig.3 (a), it can be found that the substrate signals are barely observed which meant that the signal of Ag-coated CP substrate has little influence on the detection of analytes molecules. From Fig.3 (b) it can be found that bare cellophane has no SERS activities. Therefore, the as-prepared Ag-coated CP was taken as SERS substrate using CV as molecular probe and the sensitivity, uniformity and reproducibility of the substrate were analyzed. To analyze the uniformity of the enhancement of the Raman signal, Raman mapping was conducted on the Ag-coated CP using CV as probe molecular and the results were shown in Fig.4. The area of the map was 70 μm ×70 μm area with step

ACCEPTED MANUSCRIPT size of 10 μm and 64 spectrum were collected in all. The SERS signal intensity distributions of the bands around 1620 cm-1 and 1175 cm-1 were shown in Fig.4(a) and Fig.4(b) respectively The corresponding spectra were shown in Fig.4(c). It can be found that the SERS signal intensity is quite uniform except few points. On the mapping area, the value of relative standard deviation (RSD) of the bands at

PT

1620 cm-1 and 1175 cm-1 were about 15.9 % and 15.1%, respectively, which means the cellophane-based substrate reveals good uniformity. Besides, it can be found that

RI

among the total 64 spectra, 30 spectra displayed 7.5 % RSD value of the intensity of Raman bands at 1620 cm-1 by the rule of three. As reported in [24], the RSD value is

SC

10.83% using filter paper as substrate while 30 spots were collected. Therefore, SERS intensity collected from the Ag-coated CP is more uniform than from paper-based

NU

substrates, which maybe caused of the smoother surface of the cellophane compared to filter paper-based substrate as seen in Fig.1(b).

MA

Fig.5 shows results of SERS spectra with different CV concentrations from 10-6 M to 10-9 M detected by the Ag-coated CP substrate. As seen in Fig.4, the intensity of

D

peak increased gradually with the increasing concentrations of CV. As shown in Fig.5,

PT E

typical Raman peaks of CV at 805 cm-1 (out of plane ring C-H bend), 915 cm-1 (ring skeletal vibration of radial orientation), 1175 cm-1 (in plane ring C-H bending), 1300 cm-1 (ring C-C stretching) and 1536, 1587, 1620 cm-1 (ring C-C stretching) can be

CE

obviously observed [31, 32]. The intensity of peak increased gradually with the increasing concentrations of CV. And, it can be found that 1620 cm-1 can be observed

AC

till the concentration of CV decreased to 10-9 M. The Raman enhancement factor (EF) is calculated to quantify the SERS activity. As known, EF is acquired from an average number of adsorbed molecules (N) in the scattering volume of SERS and non-SERS areas, and it assumes N = cV, where c is the concentration and V is the scattering volume which were the same because the probe molecules were uniformly distributed on paper [33, 34]. Therefore, EF was 𝐼

𝐶

calculated using the following equation: EF= (𝐼 SERS ) ( 𝐶Raman ) , where c is the Raman

SERS

concentration of CV and I is the height of CV Raman peak. Therefore, the measured

ACCEPTED MANUSCRIPT SERS intensities of 10-6 M~10-9 M CV (1620 cm−1) on the Ag–coated CP and the Raman intensity of 10-3 M CV on the bare cellophane (Fig.3(b)) were

compared,

and the calculated EFs for CV were in the range of 1.7 ×104 to 2 × 105, comparable to those of 7.5×103 [27] and 1.0×105 [35] obtained by paper-based and regular substrates respectively in previous studies .

PT

Besides, eight different Ag-coated CP substrates were tested for the sample-to-sample repeatability analysis, and RSD of 8.8% for SERS intensities of the

RI

1620 cm-1 band was obtained as seen in Fig.6, demonstrating favorable

3.3 Detection of acetamiprid in water–methanol

SC

reproducibility of the Ag NPs-coated paper.

detected by Ag-coated CP substrate.

NU

Acetamiprid was dissolved in 10 mL deionized water–methanol (1:1) and

MA

Fig.7 (a) is the molecular structure of acetamiprid while Fig. 7 (b) shows normal Raman spectrum of acetamiprid in the solid state and the SERS spectrum of 100

D

μg·mL-1 acetamiprid absorbed onto the Ag-coated CP substrate. From Fig.7 (b), it is

PT E

clear that SERS spectrum of acetamiprid is different from the Raman spectrum of the solid powder in intensity and Raman shift, which can be shown that there are some interactions between acetamiprid and silver nanoparticles. Compared to the Raman

CE

spectrum of acetamiprid, it should be noted that the SERS spectrum has a strong peak at 1033 cm-1 which comes from the ring breathing vibrational mode of pyridine,

37].

AC

proving that acetamiprid is close to the silver surface through the pyridine ring [36,

As shown in Fig.7 (c), acetamiprid with concentrations of 4.5×10-6, 4.5×10-5, 4.5×10-4 M were detected with the help of Ag-coated CP. It can be found that characteristic bands at around 1033 cm−1 can be obviously observed till the concentration of acetamiprid decreased to 4.5×10-6 M (1 μg·mL-1), meaning that the Ag-coated CP also reveals good sensitivity in detecting acetamiprid. 3.4 Time stability of the prepared CP substrate

ACCEPTED MANUSCRIPT Fig. 8 describes the time stability of the Raman signal of the CP substrates which were stored in ethanol. The SERS spectra were collected during designated days within a month. From Fig.8, it can be found that there was almost no change in the intensity of the SERS signal within 30 days, meaning that the CP substrates demonstrate good stability during preservation.

PT

4 Conclusion Ag nanoparticles were fabricated on the fibers of cellophane via silver mirror

RI

reaction. The dispersion of detection signals of SERS spectra declares the excellent

SC

SERS signal uniformity of the Ag-coated CP compared to filter paper in previous reports. Moreover, it can be found that using the cellophane-based substrate, as low as

NU

10-9 M of CV and 4.5×10-6 M of acetamiprid can be detected. It can be concluded that cellophane is suitable to be used as the platform for preparation of SERS substrates.

MA

The as-prepared Ag-coated CP substrate can be used for rapid detection of hazardous molecules with low concentrations.

D

Acknowledgement

PT E

This work is funded by the National Natural Science Foundation of China (No. 21505118) and Natural Science Foundation of Jiangsu Province of China (BK

References

CE

20150438).

AC

1. W. Fang, X. Zhang, Y. Chen, L. Wan, W. Huang, A. Shen and J. Hu, Anal. Chem. 87, 9217 (2015)

2. Q.L. Huang, J. Li, W.X. Wei, Y. P. Wu and T. Li, RSC Adv. 7, 26704 (2017) 3. N. L. Gruenke, M. F. Cardinal, M. O. McAnally, R. R. Frontiera, G. C. Schatz and R. P. Van Duyne, Chem. Soc. Rev. 45, 2263 (2016) 4. B. Sharma, R. R. Frontiera, A. I. Henry, E. Ringe and R. P. Van Duyne, Mater. Today 15, 16 (2012) 5. W. Ji, L.Wang, H.Qian and W.R. Yao, Spectrosc. Lett. 47, 451 (2014) 6. W. Ji and W.R. Yao, Spectrochim. Acta, Part A 144, 125 (2015)

ACCEPTED MANUSCRIPT 7. C.L. Zhang, K.J. Wang, D.J. Han and Q. Pang, Spectrochim. Acta, Part A 122, 387 (2014) 8. C.Q. Han, J. Chen, X.M. Wu, Y.W. Huang and Y.P. Zhao, Talanta 128, 293 (2014) 9. S. Thatai, P. Khurana, S. Prasad and D. Kumar, Talanta 134, 568 (2015) 10. X. Li, K. Zhang, J.J. Zhao, J.Ji, C. Ji and B.H. Liu, Talanta 147, 493 (2016) 11. B.S. Pereira, M.F. Silva, P.R.S. Bittencourt, D.M.F. Oliveira, E.A.G. Pineda and A.A.W.

PT

Hechenleitner, Carbohyd. Polym. 133, 277 (2015) 12. J.E.L. Villa and R.J. Poppi, Analyst 141, 1966 (2016)

RI

13. M.L. Cheng, B.C. Tsai and J. Yang, Anal. Chim. Acta. 708, 89 (2001)

14. W.L.J. Hasi, S. Lin, X.lin, X.T.Lou, F. Yang, D. Y. Lin and Z.W. Lu, Anal. Methods 6, 9547

SC

(2014)

15. W.L.J. Hasi, X. Lin, X.T. Lou, S. Lin, F.Yang, D.Y. Lin and Z.W. Lu, Appl. Phys. A 118, 799

NU

( 2015)

16. Y. H. Ngo, D. Li, G. P. Simon and G. Garnier, J. Colloid Interface Sci. 392, 237 (2013)

MA

17. K. Zhan, J.J. Zhao, H.Y. Xu, Y.X. Ji and B. H. Liu, ACS Appl. Mater. Interfaces 7, 16767 (2015)

D

18. R. Zhang, B.B Xu, X.Q. Liu, Y.L. Zhang, Y. Xu, Q.D. Chen, H.B. Sun, Chem. Commun. 48,

PT E

5913 (2012)

19. J. Wu, Y. Zheng, W. Song, J. Luan, X.X. Wen, Z. Wu, X. Chen, Q. Wang and S. Guo, Carbohydr. Polym. 102, 762 (2014)

CE

20. L.L. Qu, Y.Y. Geng, Z.N. Bao, S. Riaz and H. Li, Microchim Acta 183, 1307 (2016) 21. R. Aladpoosh and M. Montazer. Carbohydr. Polym. 141, 116 (2016)

AC

22. M. Rana, B. Hao, L. Mu, L. Chen and P.C. Ma, Compos. Sci. Technol. 122, 104 (2016) 23. W.X. Wei and Q.L. Huang. Spectrochim. Acta, Part A 179, 211 (2017) 24. Y.Q. Zhu, M.Q. Li, D.Y. Yu and L.B. Yang, Talanta 128, 117 (2014) 25. W.W. Yu and I.M. White, Analyst 138, 1020 (2013) 26. Y.H. Ngo, D. Li, G.P. Simon and G. Garnier, Langmuir 28, 8782 (2012) 27. D. Li, Q. X. Zhu, D.Y. Lv, B.X. Zheng, Y.H. Liu, Y.F. Chai and F. Lu, Anal. Bioanal. Chem. 407, 6031 (2015) 28. C.H. Lee, M.E. Hankus, L.Tian, P. M. Pellegrino and S. Singamaneni, Anal. Chem.83, 8953 (2011)

ACCEPTED MANUSCRIPT 29. A. Molla, M. Sahu and S. Hussain, Sci. Rep. 6, 26034 (2016) 30. W. Wijaya, S. Pang, T. P. Labuza and L.L He, J. Food Sci. 79, T743 (2014) 31. L.H. Fu, B. Liu, L.Y. Meng and M.G. Ma, Mater. Lett. 171, 277 (2016) 32. X. Liu, Y. Shao, Y. Tang and K.F. Yao, Sci. Rep. 4, 5308 (2014) 33. W. Kim, Y.H. Kim, H.K. Park and S. Choi, Appl. Mater. Interfaces 7, 27910 (2015)

PT

34. E.C.L. Ru, E.Blackie, M. Meyer and P. G.Etchegoin, J. Phys. Chem. C. 111, 13794 (2007) 35. J. Ye, J.A. Hutchison, H. Uji-i, J. Hofkens, L. Lagae, G. Maes, G. Borghs, P.V. Dorpe,

RI

Nanoscale 4, 1606 (2012) 36. J.A. Creighton. Surf. Sci. 124, 209 (1983)

SC

37. E. Pieta, E. Proniewicz,, A. Kudelski, T. K. Olszewski and B. Boduszek, Vib. Spectrosc.83,

AC

CE

PT E

D

MA

NU

115 (2016)

ACCEPTED MANUSCRIPT

Figure Captions Fig.1 (a) Photograph of cellophane before and after silver mirror reaction; SEM of (b) cellophane and (c) Ag-coated CP; (d) EDS of Ag-coated CP. Inset is the higher resolution image Fig.2 (a) UV-Vis and (b) XRD spectra of cellophane and Ag-coated CP

PT

Fig.3 (a) Raman spectra of Ag-coated CP (b) 10-3 M CV detected by bare cellophane

RI

Fig.4 Raman mapping images of (a) the bands around 1620 cm-1 (b) around 1175 cm-1 and (c) the corresponding Raman spectra

SC

Fig.5 SERS spectra collected by using CP substrate for CV solutions of different concentrations. Inset is the enlarged SERS spectra of 10-9 M CV

NU

Fig.6 SERS signals collected of CV from eight different Ag-coated CP Fig.7 (a) Molecualr structure of acetamiprid (b) Raman and SERS specta of

MA

acetamiprid (c) SERS sprectra of acetamiprid with different concentrations Fig.8 SERS spectra of CV using Ag-coated CP during designated days within 30 days.

AC

CE

PT E

D

Inset: SERS intensity distribution of the 1620 cm-1 bands

MA

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

Fig. 1a

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

NU

Fig. 1b

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

NU

Fig. 1c

MA

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

Fig. 1d

MA

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

Fig. 2a

MA

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

Fig. 2b

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

Fig. 3a

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

Fig. 3b

MA

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

Fig. 4a

MA

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

Fig. 4b

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

Fig. 4c

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

NU

SC

Fig. 5

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

Fig. 6

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

NU

SC

RI

Fig. 7a

MA

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

Fig. 7b

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

Fig. 7c

NU

SC

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

Fig. 8

RI

PT

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

NU

SC

Graphical abstract

ACCEPTED MANUSCRIPT

AC

CE

PT E

D

MA

NU

SC

RI

PT

Highlights  Ag nanoparticles are fabricated on the fibers of cellophane via silver mirror action.  The cellophane-based SERS substrate reveals good uniformity.  CV and acetamiprid have been detected via Ag-coated cellophane.  Cellophane is suitable to be taken as platform for preparation of SERS substrates.