Tetrahydro[5]helicene-based fluorescent probe for rapid and sensitive detection of bisulfite in living cells

Sensors & Actuators: B. Chemical 273 (2018) 1487–1494

Contents lists available at ScienceDirect

Sensors and Actuators B: Chemical journal homepage: www.elsevier.com/locate/snb

Tetrahydro[5]helicene-based fluorescent probe for rapid and sensitive detection of bisulfite in living cells

T

Kun-Peng Wanga, Yang Leia, Ying Sunb, Qingyang Zhangb, Shaojin Chena, Qi Zhanga, ⁎ ⁎ Hai-Yu Hub, , Zhi-Qiang Hua, a

Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, Key Laboratory of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, PR China b State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100050, PR China

A R T I C LE I N FO

A B S T R A C T

Keywords: Fluorescent probe Helicene Bisulfite Cell imaging

A new fluorescent probe tetrahydro[5]helicene-malononitrile derivative was designed and synthesized for selective detection of bisulfite. This fluorescent probe exhibites high response speed and selectivity toward HSO3− in PBS solution over other coexisting species accompanied by a distinct fluorescence color change from yellow to blue, which can be visually identified. The probe shows excellent sensitivity to HSO3− and the detection limit is as low as 0.27 μM. Once reacted with HSO3−, the signal-to-background ratio of fluorescence intensity can reach a 45-folds enhancement and the quantum yield dramatically increases from 1.9% to 52.3%. The response mechanism proved to be a nucleophilic addition reaction of probe with HSO3−, which was confirmed by 1H NMR, Mass titration and theory calculation. Additionally, the preliminary cell imaging experiments demonstrated that the probe could be used for intracellular bisulfite detection.

1. Introduction As a main toxic atmospheric pollutant, sulfur dioxide (SO2) might cause detrimental effects such as neurological disorders, allergic reactions, wheezing, cardiovascular diseases and lung cancer [1–4]. The toxicity of SO2 inhaled by human beings is mainly associated with HSO3−/SO32− because sulfur dioxide can easily dissolve in water to form two derivatives bisulfite (HSO3−) and sulfite (SO32−) anions [5–8]. The World Health Organization (WHO) prescribed the daily human intake of sulfite is 0–0.7 mg/Kg (calculated by SO2) and FDA (U.S. Food and Drug Administration) requires labeling of products with more than 10 μg/mL sulfite [9]. Thus, it is of great importance to develop a rapid and convenient method for the selective detection of HSO3−/SO32−. Until now, several analysis methods have been developed to detect sulfites in wines, beverages and food industries [10–12]. Among all of the detection strategies, the fluorescent method has been recognized as an effective tool for sensing bisulfite content because of the advantages such as high sensitivity and selectivity, simplicity and rapid analysis, easy readout and visible detection [13–18]. In the past decades, several fluorescent probes have been used to facilitate sensitive HSO3−/SO32− detection [19–24]. However, many of them suffer from some limits, such as long response time, low selectivity over ⁎

reactive sulfur especially for biothiols, and unsuitable in biological systems [25–27]. As a consequence, developing novel fluorescent probes for detection of HSO3−/SO32− is particularly meaningful and valuable. Recently, tetrahydro[5]helicene has been extensively used as fluorophore due to its excellent photophysical properties such as large Stokes shifts, intense fluorescence and adjustable emission by changing the substituents [28–30]. Moreover, the twisted structure of tetrahydro [5]helicene can prevent aggregation-caused fluorescence quenching (ACQ), resulting strong emission in both solution and solid state [31,32]. Herein, we report a novel fluorescent probe based on the tetrahydro[5]helicene-malononitrile derivative (HM) for the detection of bisulfite. In this work, the probe HM could be easily synthesized and displayed a rapid, colorimetric and ratiometric fluorescence response to bisulfite in the aqueous solution at the physiological pH. In addition, the probe HM had a high selectivity over other common anions and biological species, especially H2S, Cys, Hcy and GSH. The detection mechanism was demonstrated to be a nucleophilic addition of HM with bisulfite by 1H NMR titration and DFT calculation. More importantly, preliminary cell experiments also confirmed that this probe could be used for intracellular detection of HSO3−.

Corresponding authors. E-mail addresses: [email protected] (H.-Y. Hu), [email protected] (Z.-Q. Hu).

https://doi.org/10.1016/j.snb.2018.07.057 Received 15 March 2018; Received in revised form 11 July 2018; Accepted 12 July 2018 0925-4005/ © 2018 Elsevier B.V. All rights reserved.

Sensors & Actuators: B. Chemical 273 (2018) 1487–1494

K.-P. Wang et al.

Scheme 1. The synthesis route of probe HM.

2. Experimental

resulting mixture was stirred for 12 h at 90 °C. After cooling to room temperature, the mixture was extracted with ethyl acetate (100 mL). The organic layer was washed with water, dried over anhydrous MgSO4, and then concentrated in vacuum. The residue was purified by column chromatography with ethyl acetate and petroleum ether (1:5, v/v) as eluent to give compound 4 (700 mg, 85%). 1H NMR (500 MHz, CDCl3) δ = 10.04 (s, 2 H), 7.91 (d, J = 8.2 Hz, 4 H), 7.70 (d, J = 8.2 Hz, 4 H), 7.30 (s, 2 H), 6.78 (s, 2 H), 4.36 – 4.29 (m, 2 H), 4.29 – 4.21 (m, 2 H), 3.32 (s, 6 H), 3.15 – 3.06 (m, 2 H), 2.92 – 2.84 (m, 4 H), 2.78 – 2.67 (m, 2 H), 1.79 (m, 4 H), 1.26 (m, 4 H), 1.03 (t, J = 7.4 Hz, 6 H) ppm. Compound HM: To a stirred solution of 4 (0.6 g, 0.83 mmol) and malononitrile (0.16 g, 2.4 mmol) in ethanol (20 mL), two drops of piperidine was added. Under argon atmosphere, the reaction mixture was stirred at room temperature for 2 h. The residue was collected through filtration and washed with ethanol to provide HM as yellow solid without further purification (0.5 g, 73%). 1H NMR (500 MHz, DMSO) δ = 8.56 (s, 2 H), 8.00 (d, J = 8.4 Hz, 4 H), 7.77 (d, J = 8.4 Hz, 4 H), 7.47 (s, 2 H), 6.80 (s, 2 H), 4.25 (m, 4 H), 3.28 (s, 6 H), 3.10 – 2.73 (m, 6 H), 2.59 – 2.52 (m, 2 H), 1.70 – 1.62 (m, 4 H), 1.39 (m, 4 H), 0.92 (t, J = 7.4 Hz, 6 H) ppm. 13C NMR (126 MHz, CDCl3) δ 168.1, 159.3, 154.2, 144.7, 137.8, 135.2, 135.0, 131.9, 130.7, 130.4, 129.6, 129.4, 127.9, 114.3, 114.0, 112.8, 81.9, 65.7, 55.2, 30.6, 28.1, 27.7, 19.3, 13.8 ppm. HRMS (ACPI): m/z [M + NH4]+ calcd for [C54H50O6N5]+: 864.3756, found: 864.3742. For peaks assignment in the spectra, see Supplementary material. The synthetic route to probe HM is depicted in Scheme 1.

2.1. Materials and instruments Unless otherwise stated, all reagents used in this work were purchased from commercial suppliers (Heowns, Adamas-beta, Energy Chemical). Distilled water was used after passing through a water ultrapurification system. The 1H NMR and 13C NMR spectra were recorded on a Bruker AV-500 spectrometer. The absorption and fluorescent spectra were recorded with PerkinElmer Lambda 950 spectrophotometer and PerkinElmer LS-55 spectrofluorimeter. A Delta 320 pH-meter [Mettler-Toledo Instruments (Shanghai) Co, China] was used to determine pH value. 2.2. Synthesis Compound 2: Compound 2 was prepared according to a literature method [31,33]. Briefly, to a solution of 1 (10.3 g, 25 mmol) in CH2Cl2 (100 mL), bromine (16 g, 50 mmol) in acetic acid (15 mL) was added slowly for 2 h at room temperature. After stirring for another 3 h, saturated aqueous Na2SO3 was added. The organic layer was concentrated in vacuo to give a crude product, which was further purified by recrystallization from CH2Cl2 to afford compound 2 (10 g, 70%) as yellow solid. m. p.: 240–243 °C. Compound 3: A mixture of 2 (1.71 g, 3 mmol), 1-butanol (10 g), 1bromobutane (10 g) and DBU (8 g) in acetonitrile (40 mL) was refluxed overnight, and then cooled to room temperature. The solvent was removed by rotatory evaporation. The residue was dissolved in ethyl acetate (100 mL), washed with saturated brine (3 × 100 mL), dried over anhydrous MgSO4, and concentrated in vacuum. The crude solid was purified by chromatography on silica gel using ethyl acetate /petroleum ether (60–90 °C) as eluent to give a pure white product in 75% yield (1.57 g). 1H NMR (500 MHz, CDCl3) δ = 7.47 (s, 2 H), 6.57 (s, 2 H), 4.38 – 4.22 (m, 4 H), 3.36 (s, 6 H), 3.03 (d, J = 15.8 Hz, 2 H), 2.81 – 2.72 (m, 4 H), 2.68 – 2.60 (m, 2 H), 1.71 (dq, J = 13.7, 6.8 Hz, 4 H), 1.44 (dq, J = 14.8, 7.3 Hz, 4 H), 0.96 (t, J = 7.4 Hz, 6 H) ppm. Compound 4: Compound 3 (760 mg, 1.14 mmol), K2CO3 (1.57 g, 11.4 mmol), and (4-formylphenyl)boronic acid (512 mg, 3.42 mmol) were dissolved in DMF (100 mL) and water (100 mL) under argon atmosphere. Catalytic amount of Pd(PPh3)4 (5% mol) was added and the

2.3. General procedure for detection Stock solutions (1 mM) of Cys, Hcy, GSH, CO32−, SO42−, F−, Cl−, Br , I−, HPO42−, H2PO4−, NO3−, NO2−, SCN−, HSO4−, SO42−, AcO−, HS−, SO32− and HSO3− were prepared by dissolving proper amounts of sodium salts in distilled water. Stock solution of probe HM (1 mM) was prepared in ethanol. The fresh stock solutions were diluted with ethanol and PBS buffer to desired concentrations. All the detection experiments were measured in Ethanol−PBS buffer solution (10.0 μM, pH = 7.4, 1:1, v/v) at 25 °C. Fluorescence measurements were carried out with excitation and emission slit width of 5 nm and the excitation wavelength was 380 nm. −

1488

Sensors & Actuators: B. Chemical 273 (2018) 1487–1494

K.-P. Wang et al.

indicating that the response to HSO3− was completed within 4 min. The photostability of HM before and after adding HSO3− were also evaluated by consecutive illumination for 20 min. Clearly, as shown in Fig. 1a, the intensities were kept constant for at least 15 min, suggesting the probe has good photostability. The thermostability of probe HM was also investigated (see Fig. S6 in Supplementary material). As shown in Fig. S6, the fluorescence intensities maintained almost stable after HM solutions before and after adding HSO3− were incubated at different temperatures for 10 min. Owing to the good photostability and thermostability of the fluorescence, the probe HM is potential for fluorescence application in atmosphere system and suitable for real-time detection in living cells [34]. The effect of pH on the sensing behavior was also evaluated through the fluorescence of HM and HM-HSO3− at wide pH range (pH 2–12) (Fig. 1b). The fluorescence intensity of HM at 452 nm was recorded in the absence and presence of HSO3−. In Fig. 1b, there was no obvious fluorescence of free HM in the pH range of 2–9 while a slight increase was observed beyond pH 10. However, upon addition of HSO3−, there was an abrupt increase and decrease in the fluorescence intensity of HM at pH range of 4–7 and 8–10 respectively. The fluorescence intensity of HM remained almost unchanged in the pH range of 7–8. Therefore, HM was suitable for HSO3− detection in the physiological pH (7.4) and pH 7.4 was selected for the following experiments [35]. Absorption and fluorescence titration experiments were also carried out to evaluate the sensitivity, as shown in Fig. 1c and d. Upon addition of an increasing amount of HSO3−, the maximum absorption band at 378 nm decreased gradually and the absorption peak at 283 nm increased with a well-defined isosbestic point at 340 nm, indicating the formation of single new species (Fig. 1c) [36]. Similar to the evolution

2.4. The cytotoxicity of HM The cytotoxicity of HM was tested by the standard MTS assay. The HeLa cells were seeded on a 96-wells in 100 μL Dulbecco’s modified Eagle’s medium (DMEM) with 10% FBS and incubated for overnight. Upon incubation with HM at 37 °C for 48 h, 20 μL MTS was added into each well. After incubation at 37 °C for 4 h, the absorbance at 490 nm was recorded with a 2300 EnSpire multimode plate reader. All the measurements were repeated for three times. 2.5. Confocal imaging The HeLa cells were cultured for 24 h in DMEM with 10% fetal bovine serum (FBS) under humidified atmosphere of 5% CO2 at 37 °C. The HeLa cells were incubated with 10 μM HM for 1 h. Then the cells were washed with FBS for three times at 37 °C. The cells were further incubated with 50 μM NaHSO3 for 1 h. The cells were washed twice with PBS. The washed cells were performed confocal fluorescence imaging with ZEISS LSM 710 Confocal Microscope (Nikon Eclipse TE2000-E). 3. Results and discussion 3.1. Sensitivity Reaction time is an important factor for probes; therefore, the fluorescence intensity was plotted as a function of time in Fig. 1a. Upon the addition of HSO3−, the fluorescence intensity of HM at 452 nm promptly increased and reached a plateau over a period of 220 s,

Fig. 1. (a) Time course fluorescence responses of the probe (10 μM) to HSO3− (400 μM) in EtOH/PBS(1:1, v/v, pH = 7.4); (b) pH-dependent fluorescence spectra of HM (10 μM) in the absence (◆) or presence (●) of HSO3−; UV–vis absorption spectral (c) and fluorescence spectral (d) changes of HM (10 μM in EtOH/PBS) upon addition of an increasing amount of HSO3− (0–400 μM); Inset (c): The absorption at 283 nm versus concentration of NaHSO3; Inset (d): The fluorescence intensity at 452 nm versus concentration of NaHSO3. 1489

Sensors & Actuators: B. Chemical 273 (2018) 1487–1494

K.-P. Wang et al.

Fig. 4. The fluorescence response of HM (10 μM) toward HSO3− (400 μM) and various analytes (400 μM). Green bars represent the solution of HM (10 μM) in the presence of various analytes (400 μM). Red bars represent the addition of HSO3− (200 μM) to the above solution, respectively (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).

Fig. 2. The linear relationship between fluorescence intensity 452 nm upon the addition of HSO3− (0–50 μM).

trend of absorption spectra, the maximum emission band at 530 nm gradually decreased while the band at 452 nm increased significantly until the concentration of HSO3− reached 200 μM (Fig. 1d), indicating that HSO3− was the critical factor of the fluorescence increase [37]. From the titration experiment, the fluorescence intensity at 452 nm was plotted as a function of the HSO3− concentration below 50 μM, and a linear relationship was afforded with the correlation coefficient of R2 = 0.994 (Fig. 2). The detection limit was calculated to be 2.7 × 10−7 M according to the formula (3δblank/k, where δblank is the standard deviation of the blank solution and k is the slope of the calibration plot), which was superior to most of previous reported fluorescent probes for HSO3− [38,39].

interference capability over other species coexisted in the environment is an important characteristic feature. To evaluate the selectivity of probe HM for HSO3− and SO32−, UV–vis absorption and fluorescence spectra of HM toward 19 kinds of environmentally and biologically relevant species (HSO3−, SO32−, Cys, Hcy, HS−, GSH, F−, Cl−, Br−, I−, AcO−, SCN−, NO2−, NO3−, HSO4−, H2PO4−, HPO42−, SO42−, CO32−). As shown in Fig. 3a and b, most of the analytes showed no significant influence on the absorption and fluorescence spectra of HM solution. However, upon addition of HSO3− or SO32−, the absorption intensity at 378 nm decreased and the peak at 283 nm increased remarkably (Fig. 3a) accompanied with a remarkable fading, which was obvious under the naked eyes (Fig. 3c). The significant color change

3.2. Selectivity In practical application of the probe, the high selectivity and anti-

Fig. 3. (a) The absorption spectra and (b) Ratiometric responses (I452/I530) of HM (10 μM) with various species (400 μM) in EtOH/PBS(1:1, v/v, pH = 7.4); Inset (b): Fluorescence spectra of probe HM with various species (λex = 380 nm); Images of HM (10 μM) upon the addition of various species (c) in the sunlight and (d) excited by 365 nm UV light; Species: (1) blank, (2) HSO3−, (3) Cys, (4) SO32−, (5) Hcy, (6) HS−, (7) GSH, (8) F−, (9) Cl−, (10) Br−, (11) I−, (12) AcO−, (13) SCN−, (14) NO2−, (15) NO3−, (16) HSO4−, (17) H2PO4−, (18) HPO42−, (19) SO42−, (20) CO32−. 1490

Sensors & Actuators: B. Chemical 273 (2018) 1487–1494

K.-P. Wang et al.

Fig. 5. The mechanism and 1H NMR spectral change of HM in the absence (a) and presence (b) of 1 equiv. of NaHSO3 in DMSO-d6 : D2O = 9 : 1 (v/v).

Fig. 6. DFT calculated HOMO, LUMO of HM and HM-HSO3− with corresponding energy gap by Hybrid-B3LYP.

Scheme 2. The proposed response mechanism for HSO3−.

was due to the interruption of π-conjugation by HSO3−. In the presence of SO32− and HSO3−, the fluorescence ratio I452/I530 increase 42-fold and 45-fold, respectively. From Fig. 2d, HM emitted the strong blue fluorescence in the presence of HSO3− or SO32− under UV light, different to the yellow fluorescence with other species. The quantum yields of HM were measured to be 1.9% and 52.3% in the absence and presence of HSO3− using quinine sulfate in 0.1 N sulfuric acid (ΦF = 54.6%) as standard. In the presence of HS−, the absorption and fluorescence spectra displayed a certain variation, which is still far lower than that in the presence of HSO3− or SO32− [40]. The tolerance of HM over other species was also evaluated in the presence of excessive common competitive analytes. In the presence of other competing analytes, HSO3− resulted in similar response with almost no interference could be observed (Fig. 4). The results confirmed that HM had the excellent selectivity towards SO32− and HSO3− with

high anti-interference capability over other anions and biological species [41,42]. Therefore, HM has potential applications for detection of HSO3− in complex biological environments [43]. 3.3. The interaction mechanism In order to explore the probable recognition mechanism, the 1H NMR-titration experiments were performed (Fig. 5). As expected, the nucleophilic agent HSO3− attacked the active site and changed the chemical environment of the protons in the probe, which led to signal shift (Fig. 5b) [44]. Before reaction, the peak (H1) at 8.56 ppm could be ascribed to the H atom of alkene proton, while the peaks (H2 and H3) at 7.77 and 8.00 ppm could be the adjacent benzene proton. After addition of HSO3−, the peak of H1 at 8.56 ppm disappeared and reappeared at 4.4 ppm, implying that the double bond was added by HSO3− and the π 1491

Sensors & Actuators: B. Chemical 273 (2018) 1487–1494

K.-P. Wang et al.

Fig. 7. (a) Fluorescence imaging of HeLa cells incubated with probe (10 μM); (b) bright imaging of (a); (c) overlay of (a) and (b); (d) fluorescence imaging of HeLa cells incubated with probe for 1 h, and further incubated with NaHSO3 (50 μM) for 1 h; (e) bright imaging of (d); (f) overlap of (d) and (e).

microscope. As shown in Fig. 7, very weak fluorescence was observed from the HeLa cells incubated with HM (Fig. 7a–c). However, cells were pretreated with HSO3− for 1 h, followed by treatment with HM for an additional 1 h, a strong fluorescence could be observed (Fig. 7d–f), indicating good membrane permeability and visual determination of trace HSO3− in living cells [48,49].

conjugation structure was interrupted. In addition, the peaks of H2 and H3 shifted to 7.5 and 7.6 ppm respectively, because the conjugation with withdrawing cyano moieties was interrupted and resulted the raise of charge density. Further evidence for the mechanism was obtained from the ESI-MS spectrum of HM-HSO3− and the mass peak at m/z 504.1369 was corresponding to [HM-2HSO3]2− (see Fig. S4 in Supplementary material). Accordingly, the recognition mechanism could be reasonably explained by a nucleophilic addition reaction of the polarized C]C bond with HSO3−. Additionally, further theory calculations of HM and HM-HSO3− were performed to have a deep insight of the proposed mechanism. The HOMO, LUMO of HM has a delocalized electron cloud and the electron distribution shifts from the helicene moiety (donor) to the conjugated cyano moiety (acceptor) after excitation, indicating the strong intramolecular charge transfer character (ICT) via conjugated alkenylbridge (Fig. 6) [45]. The decreased electron density of the alkenylbridge by the withdrawing moieties is conducive to nucleophilic addition from HM to HM-HSO3−. After the addition of HSO3−, the electron density of HM-HSO3− is mainly localized on the helicene moiety, and the ICT process is completely changed [46]. The DFT calculation precisely demonstrates that the nucleophilic addition by HSO3− changes the π conjugation of HM and disturbs the ICT process, resulting in corresponding optical changes in absorption and emission spectra. On the basis of the above experiment results and related literatures, the reaction mechanism of HM toward HSO3− is proposed and illustrated in Scheme 2, i.e., nucleophilic addition reaction of the vinyl group with HSO3−.

4. Conclusion In conclusion, we have developed a new fluorescent probe HM for bisulfite detection via the Michael addition reaction mechanism, which was confirmed by 1H NMR titration and DFT calculations. HM has manifested high response speed and high sensitivity towards HSO3− /SO32− in the aqueous medium at physiological pH. Upon addition of HSO3− /SO32−, the absorption and emission spectra of HM exhibited obvious blue-shift, corresponding to an obvious color change from yellow to colorless which can be differentiated by naked eyes. In addition, HM showed an extra-low detection limit (2.7 × 10−7 M) and high selectivity toward HSO3− /SO32− over HS−, Cys, Hcy, GSH and other anions. More importantly, HM has been successfully applied to detect intracellular HSO3−/SO32− in cancerous cells. Acknowledgements This work was supported by the National Natural Science Foundation of China (21702116), the opening fund of Beijing National Laboratory for Molecular Sciences (BNLMS20160110) and the Doctoral Fund of QUST (010022726).

3.4. Response in vitro

Appendix A. Supplementary data

For practical application, the detection ability in living cells was necessary. To verify the feasibility of HM as a fluorescence probe in vivo, the cytotoxicity of HM was tested by the standard MTS assay [47]. After incubation with HM for 48 h, more than 80% of HeLa cells survived even when the concentration of HM was as high as 100 μM (Fig. S5 in Supplementary material). Therefore, the results of high viability in the presence of HM demonstrated that HM had low toxicity for living cells and could be a good candidate for bio-probe. Finally, cell-imaging experiments with HM were performed with confocal fluorescence

Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.snb.2018.07.057. References [1] S. Iwasawa, Y. Kikuchi, Y. Nishiwaki, M. Nakano, T. Michikawa, T. Tsuboi, J. Occup. Health 51 (2009) 38–47. [2] M. Reist, P. Jenner, B. Halliwell, Sulphite enhances peroxynitrite-dependent α1antiproteinase inactivation. A mechanism of lung injury by sulphur dioxide? FEBS

1492

Sensors & Actuators: B. Chemical 273 (2018) 1487–1494

K.-P. Wang et al.

lett. 423 (1998) 231–234. [3] Y. Zhang, L. Guan, H. Yu, Y. Yan, L. Du, Y. Liu, M. Sun, D. Huang, S. Wang, Reversible fluorescent probe for selective detection and cell imaging of oxidative stress indicator bisulfite, Anal. Chem. 88 (2016) 4426–4431. [4] Y. Yan, K. Zhang, H. Yu, H. Zhu, M. Sun, T. Hayat, A. Alsaedi, S. Wang, Sensitive detection of sulfide based on the self-assembly of fluorescent silver nanoclusters on the surface of silica nanospheres, Talanta 174 (2017) 387–393. [5] V.S. Lin, W. Chen, M. Xian, C.J. Chang, Chemical probes for molecular imaging and detection of hydrogen sulfide and reactive sulfur species in biological systems, Chem. Soc. Rev. 44 (2015) 4596–4618. [6] W. Zhang, T. Liu, F. Huo, P. Ning, X. Meng, C. Yin, Reversible ratiometric fluorescent probe for sensing bisulfate/H2O2 and its application in Zebrafish, Anal. Chem. 89 (2017) 8079–8083. [7] X. Cheng, H. Jia, J. Feng, J. Qin, Z. Li, “Reactive” probe for hydrogen sulfite: Good ratiometric response and bioimaging application, Sens. Actuators B 184 (2013) 274–280. [8] H. Yu, L. Du, L. Guan, K. Zhang, Y. Li, H. Zhu, M. Sun, S. Wang, A ratiometric fluorescent probe based on the pi-stacked graphene oxide and cyanine dye for sensitive detection of bisulfite, Sens. Actuators B 247 (2017) 823–829. [9] J. Wang, Y. Hao, H. Wang, S. Yang, H. Tian, B. Sun, Y. Liu, Rapidly responsive and highly selective fluorescent probe for bisulfite detection in food, J. Agric. Food Chem. 65 (2017) 2883–2887. [10] T. Fazio, C.R. Warner, A review of sulphites in foods: analytical methodology and reported findings, Food Addit. Contam. 7 (1990) 433–454. [11] Chinese Standards for Food Additives―GB2760-2015. [12] Q. Zhang, Y. Zhang, S. Ding, H. Zhang, G. Feng, A nearinfrared fluorescent probe for rapid, colorimetric and ratiometric detection of bisulfite in food, serum, and living cells, Sens. Actuators B 211 (2015) 377–384. [13] K.P. Wang, Y. Lei, J.P. Chen, Z.H. Ge, W. Liu, Q. Zhang, S. Chen, Z.Q. Hu, The coumarin conjugate: synthesis, photophysical properties and the ratiometric fluorescence response to water content of organic solvent, Dyes Pigm. 151 (2018) 233–237. [14] M. Li, X.J. Li, H.Y. Lu, C.F. Chen, Tetrahydro[5]helicene thioimide-based fluorescent and chromogenic chemodosimeter for highly selective and sensitive detection of Hg2+, Sens. Actuators B 202 (2014) 583–587. [15] Y. Sun, Y. Li, X. Ma, L. Duan, An A–p–A0 structural ratiometric fluorescent probe based on benzo[e]indolium for bisulfite and its application in sugar samples and living cells, RSC Adv. 6 (2016) 79830–79835. [16] X. Cheng, H. Jia, J. Feng, J. Qin, Z. Li, “Reactive” probe for hydrogen sulfite: “turnon” fluorescent sensing and bioimaging application, J. Mater. Chem. B 1 (2013) 4110–4114. [17] M. Sun, H. Yu, K. Zhang, S. Wang, T. Hayat, A. Alsaedi, D. Huang, Palladacycle based fluorescence turn-on probe for sensitive detection of carbon monoxide, ACS Sens. 3 (2018) 285–289. [18] L. Yu, Y. Li, H. Yu, K. Zhang, X. Wang, X. Chen, J. Yue, T. Huo, H. Ge, K.A. Alamry, H.M. Marwani, S. Wang, A fluorescence probe for highly selective and sensitive detection of gaseous ozone based on excited-state intramolecular proton transfer mechanism, Sens. Actuators B 266 (2018) 717–723. [19] X. Zhu, L. Zhu, H. Liu, X. Hu, R. Peng, J. Zhang, X.B. Zhang, W. Tan, A two-photon fluorescent turn-on probe for imaging of SO2 derivatives in living cells and tissues, Anal. Chim. Acta 937 (2016) 136–142. [20] Y. Huang, D. Ou, C. Wang, C. Huang, Q. Li, Z. Li, Synthesis of a cyclen-containing disubstituted polyacetylene with strong green photoluminescence and its application as a sensitive chemosensor towards sulfide anion with good selectivity and high sensitivity, Polym. Chem. 5 (2014) 2041–2049. [21] Y.Q. Sun, J. Liu, J. Zhang, T. Yang, W. Guo, Fluorescent probe for biological gas SO2 derivatives bisulfite and sulfite, Chem. Commun. 49 (2013) 2637–2639. [22] W. Zhang, T. Liu, F. Huo, P. Ning, X. Meng, C. Yin, Reversible ratiometric fluorescent probe for sensing bisulfate/H2O2 and its application in zebrafish, Anal. Chem. 89 (2017) 8079–8083. [23] Z. Chen, F. Chen, Y. Sun, H. Liu, H. He, X. Zhang, S. Wang, A novel ratiometric fluorescent probe for selective detection of bisulfite in living cells, RSC Adv. 7 (2017) 2573–2577. [24] M. Sun, H. Yu, K. Zhang, Y. Zhang, Y. Yan, D. Huang, S. Wang, Determination of gaseous sulfur dioxide and its derivatives via fluorescence enhancement based on cyanine dye functionalized carbon nanodots, Anal. Chem. 86 (2014) 9381–9385. [25] K. Xiang, S. Chang, J. Feng, C. Li, W. Ming, Z. Liu, Y. Liu, B. Tian, J. Zhang, A colorimetric and ratiometric fluorescence probe for rapid detection of SO2 derivatives bisulfite and sulfite, Dyes Pigm. 134 (2016) 190–197. [26] Y. Sun, S. Fan, S. Zhang, D. Zhao, L. Duan, R. Li, A fluorescent turn-on probe based on benzo[e]indolium for bisulfite through 1,4-addition reaction, Sens. Actuators B 193 (2014) 173–177. [27] R.Y. Tsien, M. Poenie, Fluorescence ratio imaging: a new window into intracellular ionic signaling, Trends Biochem. Sci. 11 (1986) 450–455. [28] Y. Shen, C.F. Chen, Helicenes: synthesis and applications, Chem. Rev. 112 (2012) 1463–1535. [29] M. Li, H.-Y. Lu, C. Zhang, L. Shi, Z. Tang, C.-F. Chen, Helical aromatic imide based enantiomers with full-color circularly polarized luminescence, Chem. Commun. 52 (2016) 9921–9924. [30] M. Li, Y. Niu, H.-Y. Lu, C.-F. Chen, Tetrahydro[5]helicene-based dye with remarkable and reversible acid/base stimulated fluorescence switching properties in solution and solid state, Dyes Pigm. 120 (2015) 184–189. [31] M. Li, L.-H. Feng, H.-Y. Lu, S. Wang, C.-F. Chen, Tetrahydro[5]helicene-based nanoparticles for structure dependent cell fluorescent imaging, Adv. Funct. Mater. 24 (2014) 4405–4412. [32] M. Li, W. Yao, J.-D. Chen, H.-Y. Lu, Y.S. Zhao, C.-F. Chen, Tetrahydro[5]helicene-

[33]

[34]

[35]

[36]

[37]

[38]

[39]

[40]

[41]

[42]

[43]

[44]

[45]

[46]

[47] [48]

[49]

based full-color emission dyes in both solution and solid states: synthesis, structures, photophysical properties and optical waveguide applications, J. Mater. Chem. C 2 (2014) 8373–8380. Y. Lei, K.P. Wang, S. Chen, Q. Zhang, Z.Q. Hu, A fluorescent probe based on tetrahydro[5]helicene for highly selective recognition of hydrogen sulfide, Spectrochim. Acta A 204 (2018) 295–300. L. Zhu, J. Xu, Z. Sun, B. Fu, C. Qin, L. Zeng, X. Hu, A twisted intramolecular charge transfer probe for rapid and specific detection of trace biological SO2 derivatives and bio-imaging applications, Chem. Commun. 51 (2015) 1154–1156. J. Chao, Z. Li, Y. Zhang, F. Huo, C. Yin, Y. Liu, Y. Li, J. Wang, A single fluorescent probe for multiple analyte sensing: efficient and selective detection of CNe, HSO3e and extremely alkaline pH, J. Mater. Chem. B 4 (2016) 3703–3712. Y. Yang, B. Bai, W. Xu, Z. Xu, J. Zhang, W. Li, A highly sensitive fluorescent probe for the detection of bisulfite ion and its application in living cells, Dyes Pigm. 136 (2017) 830–835. K.P. Wang, Y. Chen, Y. Liu, A polycation-induced secondary assembly of amphiphilic calixarene and its multi-stimuli responsive gelation behavior, Chem. Commun. 51 (2015) 1647–1649. Q. Zhang, Y.C. Liu, D.M. Kong, D.S. Guo, Tetraphenylethene derivatives with different numbers of positively charged side arms have different multimeric G-quadruplex recognition specificity, Chem. Eur. J. 21 (2015) 13253–13260. K.P. Wang, Y. Lei, S.J. Zhang, W.J. Zheng, J.P. Chen, S. Chen, Q. Zhang, Y.B. Zhang, Z.Q. Hu, Fluorescent probe for Fe(III) with high selectivity and its application in living cells, Sens. Actuators B 252 (2017) 1140–1145. J. Xu, J. Pan, X. Jiang, C. Qin, L. Zeng, H. Zhang, J.F. Zhang, A mitochondriatargeted ratiometric fluorescent probe for rapid, sensitive and specific detection of biological SO2 derivatives in living cells, Biosens. Bioelectron. 77 (2016) 725–732. Q. Li, Y. Liu, P. Gao, C. Xie, X. Su, X. Li, Q. Zhao, An iridium complex-based phosphorescent probe for recognition to bisulfite and cyanide in neutral aqueous system, Sens. Actuators B 252 (2017) 142–151. K.P. Wang, S.J. Zhang, C.D. Lv, H.S. Shang, Z.H. Jin, S. Chen, Q. Zhang, Y.B. Zhang, Z.Q. Hu, A highly sensitive and selective turn-on fluorescent sensor for dihydrogen phosphate in living cells, Sens. Actuators B 247 (2017) 791–796. Y. Liu, K. Li, M.Y. Wu, Y.H. Liu, Y.M. Xie, X.Q. Yu, A mitochondria-targeted colorimetric and ratiometric fluorescent probe for biological SO2 derivatives in living cells, Chem. Commun. 51 (2015) 10236–10239. K.P. Wang, D.S. Guo, H.X. Zhao, Y. Liu, Synthesis of doubly ethyl-bridged bis(psulfonatocalix[4]arene) and its supramolecular polymerization with viologen dimer, Chem. Eur. J. 20 (2014) 4023–4031. Y. Zhu, W. Du, M. Zhang, Y. Xu, L. Song, Q. Zhang, X. Tian, H. Zhou, J. Wu, Y. Tian, A series of water-soluble A–π–A′ typological indolium derivatives with two-photon properties for rapidly detecting HSO3−/SO32− in living cells, J. Mater. Chem. B 5 (2017) 3862–3869. U. Diwan, V. Kumar, R.K. Mishra, N.K. Rana, B. Koch, M.K. Singh, K.K. Upadhyay, A pyrene-benzthiazolium conjugate portraying aggregation induced emission, a ratiometric detection and live cell visualization of HSO3−, Anal. Chim. Acta 929 (2016) 39–48. Q. Zhang, Q. Wang, Y. Sun, L. Zuo, V. Fetz, H.Y. Hu, Superior fluorogen-activating protein probes based on 3-indole-malachite green, Org. Lett. 19 (2017) 4496–4499. S. Yu, X. Yang, Z. Shao, Y. Feng, X. Xi, R. Shao, Q. Guo, X. Meng, A TICT based twophoton fluorescent probe for bisulfite anion and its application in living cells, Sens. Actuators B 235 (2016) 362–369. Q. Zhang, Q. Wang, S. Xu, L. Zuo, X. You, H.Y. Hu, Aminoglycoside-based novel probes for bacterial diagnostic and therapeutic applications, Chem. Commun. 53 (2017) 1366–1369.

Kun-Peng Wang received his PhD in Organic Chemistry from Nankai University in 2015. He is working in College of Chemistry and Molecular Engineering of Qingdao University of Science and Technology as a lecture now. His current interests include supramolecular chemistry, molecular recognition and assembly, chemical and biological sensors. Yang Lei is currently a master candidate in College of Chemistry and Molecular Engineering of Qingdao University of Science and Technology. His main research fields are fluorescent probes design and chemical sensors. Ying Sun is currently a master candidate working in the Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences. Her research is focused on fluorescent probes and their biological applications. Qingyang Zhang is an assistant professor working in the Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College. His research is the development of novel imaging agents for molecular imaging. Shaojin Chen is working in College of Chemistry and Molecular Engineering of Qingdao University of Science and Technology as a lecture now. His main research fields are fluorescent probes design and chemical sensors. Qi Zhang is working in College of Chemistry and Molecular Engineering of Qingdao University of Science and Technology as a lecture now. Her main research fields are fluorescense and new materials. Hai-Yu Hu received her PhD in organic chemistry from Institute of Chemistry, Chinese Academy of Sciences in 2009. She is currently working in State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica,

1493

Sensors & Actuators: B. Chemical 273 (2018) 1487–1494

K.-P. Wang et al.

Zhi-Qiang Hu received his PhD in organic chemistry from Institute of Chemistry, Chinese Academy of Sciences in 2005. He is working in College of Chemistry and Molecular Engineering of Qingdao University of Science and Technology as a professor now. His current interests include molecular recognition, molecular assembly, chemical and biological sensors.

Peking Union Medical College and Chinese Academy of Medical Sciences as a professor. Her research interests focus on small-molecule fluorescent/MRI probes for bioimaging and sensing.

1494