Molecularly imprinted nanohybrids based on dopamine-modified poly(γ-glutamic acid) for electrochemical sensing of melamine

• Published in: Biosensors & bioelectronics 2016-11, Vol.85, p.381-386
• Main Authors: Zhang, Rongli, Xu, Sheng, Zhu, Ye, Zhao, Wei, Luo, Jing, Liu, Xiaoya, Tang, Dingxing
• Format: Article
• Language: English
• Subjects: Ag nanoparticles; Animals; Biosensing Techniques - methods; Detection; Dopamine; Dopamine - analogs & derivatives; Electrochemical Techniques - methods; Electrodes; Food Analysis - methods; Limit of Detection; Melamine; Melamine sensor; Milk - chemistry; Molecular Imprinting; Molecularly imprinted nanohybrids; Nanoparticles; Nanoparticles - chemistry; Nanoparticles - ultrastructure; Nanostructure; Poly(γ-glutamic acid) nanoparticles; Polyglutamic Acid - analogs & derivatives; Polyglutamic Acid - chemistry; Sensors; Silver; Silver - chemistry; Triazines - analysis
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2016.05.030

A voltammetric sensor for melamine (MEL) was prepared from molecularly imprinted nanohybrids (MINBs). A dopamine modified poly-γ-glutamic acid copolymer (γ-PGA-DA) and MEL were self-assembled into MEL/γ-PGA-DA nanoparticles (NPs) in aqueous solution via weak interactions, followed by adding an aqueous AgNO3 solution into the mixture. The Ag+ was adsorbed in the MEL/γ-PGA-DA NPs and spontaneously reduced to Ag NPs by the dopamine moieties of γ-PGA-DA, forming Ag/MEL/γ-PGA-DA MINBs, which were then cast on a gold electrode to form a MINBs film. The MEL was removed by electrolysis via catalysis of Ag NPs at a constant potential of 1.4V in phosphate buffer saline solution, to obtain a voltammetric sensor for MEL. The sensor responded linearly to MEL in the concentration range of 5×10−18 to 5×10−7molL−1. Compared to other published molecularly imprinted polymer sensors for sensing MEL, the prepared MINBs sensor had much wider detection range with lower detection limit. •A voltammetric sensor for melamine was prepared from molecularly imprinted nanohybrids.•The molecularly imprinted nanohybrids were prepared through self-assembly and in situ reduction methods.•The sensor responds linearly to melamine in the concentration range of 5×10−18 to 5×10−7molL−1.