A very low potential electrochemical detection of L-cysteine based on a glassy carbon electrode modified with multi-walled carbon nanotubes/gold nanorods

作者：dos Santos Silva Francisco de Assis; Angelo da Silva Monique Gabriella; Lima Phabyanno Rodrigues; Meneghetti Mario Roberto; Kubota Lauro Tatsuo; Fonseca Goulart Marilia Oliveira

来源：Biosensors and Bioelectronics, 2013, 50: 202-209.

DOI：10.1016/j.bios.2013.06.036

• Gold nanorods
• MWCNT
• L-cysteine
• Electrocatalysis
• Chemically modified electrodes

A nanohybrid platform built with multi-walled carbon nanotubes and gold nanorods, prepared via a cationic surfactant-containing seed-mediated sequential growth process, in aqueous solution, on a glassy carbon substrate has been successfully developed to be used in the electrocatalytic oxidation of L-cysteine (Cys). The nanohybrid was characterized by transmission electron microscopy, Raman spectroscopy and electrochemical measurements. Cyclic voltammetry results had shown that the modified electrode allows the oxidation of Cys at a very low anodic potential (0.00 V vs. Ag/AgCl). The kinetic constant k(cat) for the catalytic oxidation of Cys was evaluated by chronoamperometry and provided a value of 5.6 x 10(4) L mol(-1) s(-1). The sensor presents a linear response range from 5.0 up to 200.0 mu mol L-1, detection limit of 8.25 nmol L-1 and a sensitivity of 120 nA L mu mol(-1).

• 出版日期2013-12-15