Sensor Based on a Poly[2-(Dimethylamino)ethyl Methacrylate-Co-Styrene], Gold Nanoparticles, and Methylene Blue-Modified Glassy Carbon Electrode for Melamine Detection

Abstract

Melamine has been used as a non-protein nitrogenous additive in food products to artificially increase the apparent “false” protein content. Melamine is known as a dangerous and poisonous substance for human health and it causes diverse diseases. An electrochemical sensor for melamine detection has been developed by modification of a glassy carbon electrode using copolymer poly[DMAEMA-co-styrene], gold nanoparticles, and methylene blue. The characterization of the modified electrode was conducted using several analysis techniques including cyclic voltammetry (CV), differential pulse voltammetry (DPV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The electrochemical detection of melamine was performed by impedance spectroscopy. Obtained results revealed that the developed sensor has a large detection range from 5.0 × 10−13 to 3.8 × 10−8 M with a low detection limit of 1.8 × 10−12 M (at S/N = 3). Various interfering species such as phenol, hydroquinone, and bisphenol A have been used and their behavior on modified electrode has been studied.

A Higher Affinity Melamine Binding Aptamer Mutant for More Sensitive Detection

“…The limit of detection (LOD) of these methods is about 0.0081 pg mL À 1 -0.6 μg mL À 1 for high performance liquid chromatography (HPLC) [6,7] , 0.006 μg mL À 1 for Gas Chromatography-Mass Spectrometry (GC-MS), [8] but the instrumental method is complicated, expensive and professional. With the rapid development of nanomaterials, a serious novel methods by using nanomaterials were established, including electrochem-ical method [9] with LOD of 2 pM-288 nM, [10,11] , localized surface plasmon resonance (LSPR) with LOD of 0.08 nM-158 nM, [12,13] , surface-enhanced raman scattering (SERS) with LOD of 1 pM-0.08 mM, [14,15] , but these methods haven't been standardized and commercialized.…”

A Fluorescence-Based Chemical Sensor for Detection of Melamine in Aqueous Solutions

“…The detection mechanism was based on strong H-bonding interaction between melamine and the cyanuric acid group, which has a complementary H-bonding motif to that of melamine. Since then, several other nanoparticle-based sensors have been reported with different mechanisms and concentration ranges of detection, based on metal nanoparticles, imprinted polymers, and aptamers [5,[8][9][10][11][12]. While many of these techniques can detect melamine at very low concentrations (nano-and femtomolar), they still suffer from several limitations, such as high cost, unidentified detection mechanisms (and thus high level of interference) and/or complicated optimization mechanisms [9,13,14].…”