TY - JOUR
T1 - Platinum-catalyzed hydrogen evolution reaction for sensitive electrochemical immunoassay of tetracycline residues
AU - Que, Xiaohua
AU - Chen, Xian
AU - Fu, Libing
AU - Lai, Wenqiang
AU - Zhuang, Junyang
AU - Chen, Guonan
AU - Tang, Dianping
PY - 2013
Y1 - 2013
N2 - A new signal amplification strategy for sensitive electrochemical determination of tetracycline (TC) was developed by using platinum-catalyzed hydrogen evolution reaction (HER) on an anti-TC antibody-modified immunosensor. To construct such a HER, platinum nanoparticles were initially deposited to graphene nanosheets, and the as-synthesized platinum/graphene nanosheets (PtGN) were then used for the labeling of tetracycline-bovine serum albumin conjugates (TC-BSA). With a competitive immunoassay format, the resulting immunosensor was immersed into a platinum developer solution containing 1.0 mM PtCl42-, 0.1 M formate (reductant) and 0.5% Tween 80 (pH 6.5) to promote the platinum growth. The amplified electrochemical signal mainly derived from the platinum-catalyzed HER in an acidic medium containing 10 mM HCl and 1.0 M KCl. Two labeling methods and assay protocols including Pt-labeled TC-BSA and PtGN-labeled TC-BSA with or without the platinum enhancement were investigated for determination of target TC, respectively, and improved analytical features were obtained with graphene nanosheets and platinum growth mechanism. With PtGN-labeled TC-BSA, the effects of incubation time for antigen-antibody reaction and deposition time of platinum on the currents of the immunosensors were also studied. The strong attachment of TC-BSA to the PtGN resulted in a good repeatability and intermediate precision down to 9.8%. The dynamic concentration range spanned from 0.05 ng/mL to 100 ng/mL tetracycline with a low detection limit of 6 pg/mL at the 3s blank level. In addition, the methodology was further validated with tetracycline spiked samples including honey, milk and peanut, and the recoveries were 86-118%.
AB - A new signal amplification strategy for sensitive electrochemical determination of tetracycline (TC) was developed by using platinum-catalyzed hydrogen evolution reaction (HER) on an anti-TC antibody-modified immunosensor. To construct such a HER, platinum nanoparticles were initially deposited to graphene nanosheets, and the as-synthesized platinum/graphene nanosheets (PtGN) were then used for the labeling of tetracycline-bovine serum albumin conjugates (TC-BSA). With a competitive immunoassay format, the resulting immunosensor was immersed into a platinum developer solution containing 1.0 mM PtCl42-, 0.1 M formate (reductant) and 0.5% Tween 80 (pH 6.5) to promote the platinum growth. The amplified electrochemical signal mainly derived from the platinum-catalyzed HER in an acidic medium containing 10 mM HCl and 1.0 M KCl. Two labeling methods and assay protocols including Pt-labeled TC-BSA and PtGN-labeled TC-BSA with or without the platinum enhancement were investigated for determination of target TC, respectively, and improved analytical features were obtained with graphene nanosheets and platinum growth mechanism. With PtGN-labeled TC-BSA, the effects of incubation time for antigen-antibody reaction and deposition time of platinum on the currents of the immunosensors were also studied. The strong attachment of TC-BSA to the PtGN resulted in a good repeatability and intermediate precision down to 9.8%. The dynamic concentration range spanned from 0.05 ng/mL to 100 ng/mL tetracycline with a low detection limit of 6 pg/mL at the 3s blank level. In addition, the methodology was further validated with tetracycline spiked samples including honey, milk and peanut, and the recoveries were 86-118%.
KW - Electrochemical immunoassay
KW - Platinum-based seed-growth method
KW - Platinum-catalyzed hydrogen evolution reaction
KW - Platinum-graphene hybrid nanosheets
KW - Tetracycline
UR - http://www.scopus.com/inward/record.url?scp=84881150116&partnerID=8YFLogxK
U2 - 10.1016/j.jelechem.2013.06.023
DO - 10.1016/j.jelechem.2013.06.023
M3 - Article
AN - SCOPUS:84881150116
SN - 1572-6657
VL - 704
SP - 111
EP - 117
JO - Journal of Electroanalytical Chemistry
JF - Journal of Electroanalytical Chemistry
ER -