Abstract
Nanostructured electrochemical sensors often suffer from irreversible aggregation and poor adhesion to the supporting materials, resulting in reduced sensitivity and selectivity over time. We describe a versatile method for fabrication of a H2O2 sensor by immobilizing copper nanoparticles (Cu NPs; 20 nm) on graphene oxide (GO) sheets via in-situ reduction of copper(II) on a polydopamine (PDA) coating on a glassy carbon electrode. The PDA film with its amino groups and catechol groups acts as both a reductant and an adhesive that warrants tight bonding between the Cu NPs and the support. The modified electrode, best operated at a working voltage of -0.4 V (vs. Ag/AgCl), has a linear response to H2O2 in the 5 μM to 12 mM concentration range, a sensitivity of 141.54 μA∙mM‾1∙cm‾2, a response time of 4 s, and a 1.4 μM detection limit (at an S/N ratio of 3). The sensor is highly reproducible and selective (with minimal interference to ascorbic acid and uric acid). The method was applied to the determination of H2O2 in sterilant by the standard addition method and gave recoveries between 97% and 99%.
MeSH terms
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Ascorbic Acid / chemistry
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Biosensing Techniques / instrumentation
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Biosensing Techniques / methods
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Copper / chemistry*
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Electrochemical Techniques / instrumentation
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Electrochemical Techniques / methods
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Electrodes
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Graphite / chemistry*
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Hydrogen Peroxide / analysis*
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Hydrogen Peroxide / chemistry
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Indoles / chemistry*
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Metal Nanoparticles / chemistry*
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Oxides / chemistry*
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Polymers / chemistry*
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Reproducibility of Results
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Uric Acid / chemistry
Substances
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Indoles
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Oxides
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Polymers
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polydopamine
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Uric Acid
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Graphite
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Copper
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Hydrogen Peroxide
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Ascorbic Acid
Grants and funding
R.S.C. acknowledges support by the National Natural Science Foundation of China under award number 21105077, the Open Funds of Key Laboratory of Analytical Chemistry for Biology and Medicine of Ministry of Education under contract number ACBM2014001, and the Open Funds of Key Laboratory of Inorganic Coating Materials of Chinese Academy of Sciences KLICM-2013-05. F.L. thanks the National Natural Science Foundation of China under award number 21372183, Hubei Provincial Natural Science Foundation of China 2013CFB328, Wuhan Applied Basic Research Programs of China 2015060101010069, and the Open Funds of the State Key Laboratory of Electroanalytical Chemistry SKLEAC201609. S.M.L. acknowledges support by the Thousand Youth Talents Program.