A novel molecularly imprinted impedimetric sensor for melamine determination

• Published in: Talanta (Oxford) Vol. 101; pp. 374 - 381
• Main Authors: Wu, Bowan, Wang, Zhihua, Zhao, Dongxia, Lu, Xiaoquan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-11-2012; Elsevier
• Subjects: 2-Mercaptobenzimidazole; Analytical chemistry; Atomic force microscopy; Character recognition; Chemistry; Dielectric Spectroscopy - instrumentation; Electrochemical impedance; Electrochemical impedance spectroscopy; Electrochemical methods; Electrodes; Exact sciences and technology; General, instrumentation; Limit of Detection; Melamine; Microscopy, Atomic Force; Molecular Imprinting; Molecularly imprinted; Monitors; Polymerization; Sensors; Spectrometric and optical methods; Spectrophotometry, Infrared; Triazines - analysis; 2-Mercaptobenzimidazole; Electrochemical impedance; Melamine; Molecularly imprinted; Atomic force microscopy; Molecular structure; Force; Electrochemical method; Interference; Foodstuff; Chemical sensor; Electrochemical polymerization; Surface structure; Infrared spectrometry; Cyclic voltammetry; Molecules; Sensitivity; Detection limit; Morphology; Impedance; Application; Molecular imprinting; Donor acceptor interaction; Electrochemical impedance spectroscopy
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2012.09.044

A novel molecularly imprinted (MIP) impedimetric sensor was promoted for selective detecting melamine (MEL). The Au electrode modified with MIP poly (2-mercaptobenzimidazole) (PMBI) was prepared by electrochemical polymerization of 2-mercaptobenzimidazole (2-MBI) with cyclic voltammetry (CV) in the presence of template molecule MEL. The surface morphology and structure of MIP PMBI are characterized by atomic force microscopy (AFM), infrared spectra (IR), electrochemical impedance spectroscopy (EIS), and CV. The main driving force of recognition is the π-donor–acceptor interaction between MEL and PMBI. The imprinted electrode could avoid the interference successfully. In addition, a linear response curve was obtained from 1.0×10−8M to 5.0×10−5M, with the detection limit of 3.0×10−9M. The sensor exhibits remarkable advantages, such as higher sensitivity, wider linear range and lower detection limit. The effective method has a potential application to monitor nonelectrochemically active substances in food analysis in the future.
► We developed a novel MIP impedimetric sensor for melamine determination. ► The sensor was fabricated by electrochemical polymerization of 2-MBI MIPs films. ► The sensor is reusable and has great improvement in sensitivity and selectivity. ► It is a fast and real-time method for the detection of melamine in real samples. ► It is an effective method to monitor nonelectrochemically active substances.