Abstract: p-Nitrophenylphosphate (PNPP) is usually employed as the substrate for enzyme-linked immunosorbent assays. p-Nitrophenol (PNP), the product of PNPP, with the catalyst alkaline phosphatase (ALP), will passivate an electrode, which limits applications in electrochemical analysis. A novel anti-passivation ink used in the preparation of a graphene/ionic liquid/chitosan composited (rGO/IL/Chi) electrode is proposed to solve the problem. The anti-passivation electrode was fabricated by directly writing the graphene-ionic liquid-chitosan composite on a single-side conductive gold strip. A glassy carbon electrode, a screen-printed electrode, and a graphene-chitosan composite-modified screen-printed electrode were investigated for comparison. Scanning electron microscopy was used to characterize the surface structure of the four different electrodes and cyclic voltammetry was carried out to compare their performance. The results showed that the rGO/IL/Chi electrode had the best performance according to its low peak potential and large peak current. Amperometric responses of the different electrodes to PNP proved that only the rGO/IL/Chi electrode was capable of anti-passivation. The detection of cardiac troponin I was used as a test example for electrochemical immunoassay. Differential pulse voltammetry was performed to detect cardiac troponin I and obtain a calibration curve. The limit of detection was 0.05 ng/ml.

一种用于电化学免疫分析的抗钝化的电极浆料

[1]Aneesh K, Berchmans S, 2017. Highly selective sensing of dopamine using carbon nanotube ink doped with anionic surfactant modified disposable paper electrode. J Solid State Electrochem, 21(5):1263-1271.

[2]Bansod B, Kumar T, Thakur R, et al., 2017. A review on various electrochemical techniques for heavy metal ions detection with different sensing platforms. Biosens Bioelectron, 94:443-455.

[3]Budnikov HC, Shirokova VI, 2013. Term “Nano” in electroanalysis: a trendy prefix or a new stage of its development? J Anal Chem, 68(8):663-670.

[4]Cinti S, Basso M, Moscone D, et al., 2017. A paper-based nanomodified electrochemical biosensor for ethanol detection in beers. Anal Chim Acta, 960:123-130.

[5]Dinesh B, Saraswathi R, Kumar AS, 2017. Water based homogenous carbon ink modified electrode as an efficient sensor system for simultaneous detection of ascorbic acid, dopamine and uric acid. Electrochim Acta, 233:92-104.

[6]Ghosale A, Shrivas K, Shankar R, et al., 2017. Low-cost paper electrode fabricated by direct writing with silver nanoparticle-based ink for detection of hydrogen peroxide in wastewater. Anal Chem, 89(1):776-782.

[7]González-Sánchez MI, Valero E, Compton RG, 2016. Iodine mediated electrochemical detection of thiols in plant extracts using platinum screen-printed electrodes. Sens Actuators B Chem, 236:1-7.

[8]Idris A, Saleh TA, Sanhoob MA, et al., 2017. Electrochemical detection of thiocyanate using phosphate-modified zeolite carbon paste electrodes. J Taiwan Inst Chem Eng, 72: 236-243.

[9]Kuila T, Bose S, Khanra P, et al., 2011. Recent advances in graphene-based biosensors. Biosens Bioelectron, 26(12):4637-4648.

[10]Li S, Zhang Q, Lu YL, et al., 2017. One step electrochemical deposition and reduction of graphene oxide on screen printed electrodes for impedance detection of glucose. Sens Actuators B Chem, 244:290-298.

[11]Li SJ, Zuo Y, Huang WF, 2017. Establishment of a reference interval for high-sensitivity cardiac troponin I in healthy adults from the Sichuan area. Medicine, 96(14):e6252.

[12]Ma XY, Chao MY, Wang ZX, et al., 2012. Electrochemical detection of dopamine in the presence of epinephrine, uric acid and ascorbic acid using a graphene-modified electrode. Anal Methods, 4(6):1687-1692.

[13]Molazemhosseini A, Magagnin L, Vena P, et al., 2017. Single-use nonenzymatic glucose biosensor based on CuO nanoparticles ink printed on thin film gold electrode by micro-plotter technology. J Electroanal Chem, 789:50-57.

[14]Nesakumar N, Sethuraman S, Krishnan UM, et al., 2016. Electrochemical acetylcholinesterase biosensor based on ZnO nanocuboids modified platinum electrode for the detection of carbosulfan in rice. Biosens Bioelectron, 77: 1070-1077.

[15]Ping JF, Wu J, Ying YB, 2010. Development of an ionic liquid modified screen-printed graphite electrode and its sensing in determination of dopamine. Electrochem Commun, 12(12):1738-1741.

[16]Ping JF, Wang YX, Ying YB, et al., 2012a. Application of electrochemically reduced graphene oxide on screen-printed ion-selective electrode. Anal Chem, 84(7):3473-3479.

[17]Ping JF, Wu J, Wang YX, et al., 2012b. Simultaneous determination of ascorbic acid, dopamine and uric acid using high-performance screen-printed graphene electrode. Biosens Bioelectron, 34(1):70-76.

[18]Preechaworapun A, Dai Z, Xiang Y, et al., 2008. Investigation of the enzyme hydrolysis products of the substrates of alkaline phosphatase in electrochemical immunosensing. Talanta, 76(2):424-431.

[19]Saita T, Yamamoto Y, Hosoya K, et al., 2017. An ultra-specific and sensitive sandwich ELISA for imatinib using two anti-imatinib antibodies. Anal Chim Acta, 969:72-78.

[20]Sajid M, Nazal MK, Mansha M, et al., 2016. Chemically modified electrodes for electrochemical detection of dopamine in the presence of uric acid and ascorbic acid: a review. TrAC Trend Anal Chem, 76:15-29.

[21]Secor EB, Ahn BY, Gao TZ, et al., 2015. Rapid and versatile photonic annealing of graphene inks for flexible printed electronics. Adv Mater, 27(42):6683-6688.

[22]Tang WZ, Wu J, 2014. Amperometric determination of organophosphorus pesticide by silver electrode using an acetylcholinesterase inhibition method. Anal Methods, 6(3):924-929.

[23]Tang WZ, Zhou JZ, Yang QQ, et al., 2014. Determination of methyl parathion by solid-phase extraction on an ionic liquid-carbon nanotube composite electrode. Anal Methods, 6(15):5886-5890.

[24]Wang YX, Ping JF, Ye ZZ, et al., 2013. Impedimetric immunosensor based on gold nanoparticles modified graphene paper for label-free detection of Escherichia coli O157:H7. Biosens Bioelectron, 49:492-498.

[25]Yang SX, Chen YC, Nicolini L, et al., 2015. “Cut-and-Paste” manufacture of multiparametric epidermal sensor systems. Adv Mater, 27(41):6423-6430.

[26]Yu XW, Sheng KX, Shi GQ, 2014. A three-dimensional interpenetrating electrode of reduced graphene oxide for selective detection of dopamine. Analyst, 139(18):4525-4531.

[27]Zheng QQ, Yu YH, Fan K, et al., 2016. A nano-silver enzyme electrode for organophosphorus pesticide detection. Anal Bioanal Chem, 408(21):5819-5827.

[28]List of electronic supplementary materials

[29]Fig. S1 Absorbance of test solution with different kinds of blocking solutions

[30]Fig. S2 Absorbance of test solution with different concentrations of capture antibody

[31]Fig. S3 Absorbance of test solution with different concentrations of ALP-conjugated antibody