Competitive approach to the electrochemical detection of phosphopeptides on a porous ZrO2 thin film electrode
A competitive adsorption strategy has been designed to electrochemically detect phosphopeptides (P-peptides) based on the specific binding between ZrO2 and P-peptides.In this method,a porous ZrO2 thin film electrodeposited on a glassy carbon electrode was used to competitively capture P-peptides from their mixture with non-phosphopeptides labelled with electrochemical probe of ferrocene (Fc-peptides).The Fc-peptides previously adsorbed on the ZrO2 film modified electrode to saturation can be replaced by the non-electroactive P-peptides by competing the binding sites on ZrO2,resulting in a decrease of peak current of Fc-peptide/ZrO2 modified electrode.The change of peak current is directly related to the concentration of the P-peptides in solution,and thus,P-peptides can be quantitatively determined.The results reveal that the decreased peak current is linear proportional to the logarithm of the concentration of P-peptides from 0.1 μM to 500 μM with a detection limit of 0.0934 μM(S/N=3),showing the high sensitivity of the competitive biosensor.Results show that the adsorption of Fc-peptides on the modified electrode follows the first-order kinetics.The binding rate constant kb and the dissociation rate constant kd are calculated as 49.6 M-1 s-1 and 1.97 × 10-3 s-1,respectively.The present approach offers a useful platform for the detection of phosphopeptides and will be a promising strategy for the electrochemical study of protein post-translational modification.
Competitive adsorption Adsorption kinetics Non-phosphopeptides Phosphopeptides Biosensor
Fei-Fei Gao Yue-Bo Wang Kang Wang Xing-Hua Xia
School of Chemical Engineering,Shandong University of Technology,Zibo 255049,China State Key Laboratory of Analytical Chemistry for Life Science,School of Chemistry and Chemical Engin
国际会议
南京
英文
97-102
2016-12-23（万方平台首次上网日期，不代表论文的发表时间）