Computer–aided study and multivariate optimization of nanomolar metformin hydrochloride analysis using molecularly imprinted polymer electrochemical sensor based on silver nanoparticles

کد مقاله : 1061-CNF

نویسندگان

زینب خلیلی *، عزیزاله نژادعلی دانشگاه پیام نور

چکیده مقاله

In this research project, a selective and sensitive sensor was electrochemically designed to measure metformin hydrochloride (MET) based on molecularly imprinted polypyrrole (MIP). The two primary compounds in MIP synthesis are template and monomer, and in the first stage, functional monomers are placed around the template. The interaction between the template and functional monomers are covalent, semi–covalent and non–covalent imprinting in three ways, that non-covalent imprinting is more used for the preparation of MIP [1, 2]. After the polymerization process, the template is extracted, and many same cavities are produced that in size and shape are complimentary with the specific template. To prepare the sensor, the polypyrrole (PPy) was electrochemically synthesized on a pencil graphite electrode (PGE), which modified with silver nanoparticles (AgNPs). In this study, AgNPs was used because these nanoparticles not only have a good electrocatalytic effect, but they are easy to operate and quite stable in aqueous environment. The use of AgNPs increases the electrode surface area and thus increases the peak current intensity, so the electrode surface was covered with AgNPs before polymer synthesis [3]. Three electrochemical approaches, including chronoamperometry, Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were performed using an Auto lab PGSTAT 12 potentiostat–galvanostat controlled by GPES 4.9 software (Ecochemie, The Netherlands). A three–electrode cell, including MIP–modified–PGE, Ag/AgCl, and platinum was used for all measurements as the working electrode, reference electrode, and auxiliary electrode, respectively. CV and DPV techniques were performed to fabricate the sensor and quantitative measurements, respectively [3, 4]. To select the functional monomers, a computational method of density functional theory (DFT) was used [1]. Some critical factors controlling the performance of the MIP–AgNPs–PGE were optimized using Plackett–Burman design (PBD) and central composite design (CCD) methods [2]. Under optimal conditions, a calibration curve was obtained in the range 0.1 to 1000 µM with a limit of detection (LOD) of 6.8 nM (S/N=3, n=3) and limit of quantitation (LOQ) of 22.8 nM (S/N=10, n=3). RSD of 3.9% and 4.1% were obtained for repeatability and reproducibility of the system, respectively. Furthermore, the modified sensor was successfully used for the determination of MET concentration in some real samples.

کلیدواژه ها

Molecularly imprinted polymer; Metformin; Silver nanoparticles; Electrochemical study; Multivariate optimization

وضعیت: چکیده برای ارائه به صورت پوستر پذیرفته شده است