Simple, fast, and sensitive molecularly imprinted composite thin-film-based electrochemical sensor developed by using in situ co-electropolymerization of aniline and acrylic acid in the presence of melamine as a template is described here. The prepolymerization complex formation was studied by using Fourier transform infrared (FTIR) spectrophotometry, while the film formation was performed and characterized by cyclic voltammetry, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM). The optimization of important parameters and removal of melamine generated the binding sites in the polymer matrix, which can recognize melamine specifically. Electrochemical measurements were performed to achieve the linear range, the limit of quantification, and limit of detection of 0.1–180, 0.0573, and 0.0172 nM, respectively. The sensitivity of the sensor was attributed to the synergistic effects of amine from aniline and the carboxylic group from acrylic acid to form multiple noncovalent interactions with the template. Melamine-spiked infant formula and raw milk were analyzed by the developed sensor, and the recovery range of 95.87–105.63% with a relative standard deviation of 1.11–2.23% was obtained. The results showed that the developed sensor using the new composite polymer receptor is promising for the online monitoring of melamine in the food industries in the future.

Molecularly imprinted polymer-modified glassy carbon electrode (GCE)-based electrochemical sensor is prepared using the electropolymerization of aniline in the presence of melamine (MA) as a template. In this work, the advantages of molecularly imprinted conducting polymers (MICPs) and electroanalytical methods were combined to obtain an electronic device with better performances. The sensor performance was evaluated by cyclic voltammetry (CV) and square wave voltammetry (SWV) with the linear range of 0.6-16 × 10 −9 M, quantification limit of 14.9 × 10 −10 M, and detection limit of 4.47 × 10 −10 M (S/N = 3). The selectivity of the sensor was tested in the presence of acetoguanamine (AGA), diaminomethylatrazine (DMT), casein, histidine, and glycine interfering molecules taken at the triple concentration with MA that demonstrated too small current response compared with that of the analyte indicating high specificity of the sensor towards the template. The sensor was successfully applied to determine MA in infant formula samples with significant recovery greater than 96% and relative standard deviation (RSD) less than 4.8%. Moreover, the good repeatability, recyclability, and stability make this sensor device promising for the real-time monitoring of MA in different food stuffs. K E Y W O R D Selectrochemical sensor, glassy carbon electrode, imprinted polyaniline, melamine

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In this research report, we prepared an electrochemical sensor based on the molecularly imprinted poly(p‐aminophenol) supported by silver nanoparticles capped with 2‐mercaptobenzoxazole for the selective and sensitive detection of endocrine disrupting 17‐β‐estradiol (E2). The electropolymerization of the functional monomer prepared the proposed molecularly imprinted polymer (MIP) composite‐based sensor in the presence of E2 as a template. The recognition materials were characterized using Fourier transform infrared, cyclic voltammetry (CV), square wave voltammetry (SWV), scanning electron microscopy, energy‐dispersive X‐ray spectroscopy and X‐ray powder diffraction techniques. The electrochemical measurements were performed by employing both CV and SWV methods. We did the optimization of critical parameters affecting the sensor performances through the experimental design and verification. The developed sensor showed a linear range from 10 pM to 100 nM with the calculated quantification and detection limits of 1.86 and 6.19 pM, respectively. The incorporation of AgNP with high electrical conductivity into the MIP matrix enhanced the sensor's performance. Furthermore, the sensor was applied to determine E2 in real water samples without any sample preconcentration steps to achieve the percent recovery of 91.87% to 98.36% and acceptable reusability and storage stability performances.