Electrochemical sensing of bisphenol A based on carboxylated multiwalled carbon nanotubes-ferrocene-H5PMo10V2O40 with chitosan for signal amplification
Xiurong Zhai, Qian Li, Xin Zhao, Ning Yao, He Li, Dan Zhao, Jingquan Sha, Zhenglu Miao, Shengyu Liu
Abstract
A synergetic signal amplification detection platform based on carboxylated multiwalled carbon nanotubes-ferrocene-H 5 PMo 10 V 2 O 40 (CMWNT-Fc-PMo 10 V 2 ) composite is initially developed to detect bisphenol A (BPA). The CMWNT-Fc-PMo 10 V 2 composite has been synthesized by the interaction of Fc and PMo 10 V 2 with CMWNT as the loading support. Furthermore, the CMWNT-Fc-PMo 10 V 2 composite with negative charge could be firmly immobilized on the cationic chitosan (CHIT) matrix with film-forming ability through the electrostatic attraction, which could overcome the problems that Fc and PMo 10 V 2 could not be stably fixed on the electrode surface. Benefiting from the large surface area and good conductivity of CMWNT, fast electron-transfer rate and low oxidation potential of Fc, and strong redox property of PMo 10 V 2 , CMWNT-Fc-PMo 10 V 2 -based sensor demonstrates synergistic effect in electrochemical detection of BPA. Under the optimal experimental conditions, the wide linear range from 0.06 to 100 μM, and low detection limit of 0.035 μM for BPA was achieved at the CMWNT-Fc-PMo 10 V 2 sensing interface. Moreover, the newly developed electrochemical method was successfully used for determination of BPA in milk samples with satisfactory results.