A NOVEL ELECTROCHEMICAL SENSOR BASED ON METAL NANOPARTICLES AND MOLECULARLY IMPRINTED POLYMER NANOCOMPOSITE WITH BIOLOGICAL APPLICATIONS

Metal nanoparticles trapped in a biopolymer composite due to electrical conductivity properties improve electrochemical sensors with biomedical and environmental applications. The study aims are to design a novel molecularly imprinted polymer (MIP) composite based on magnetic graphene oxide (Fe3O4@GO) modified silica (SiO2) and gold nanoparticles (AuNPs) to electrochemical detect serotonin (5-hydroxytryptamine, 5-HT). A suitable amount of 5-HT is effective on motivational functions and the environment because it is a serotonergic neurotransmitter. But the desired nanocomposite may have a relatively low recognition, therefore must be in choosing the type of functional monomer be careful. In this regard, the design of the electrochemical sensor began by synthesis of Fe3O4@GO-SiO2@AuNPs nanocomposite. Then, MIP electropolymerization was carried out by using p-aminothiophenol (PATP)-functionalized Fe3O4@GO-SiO2@AuNPs nanocomposite in the presence of 5HT as a template molecule. Electrochemical polymerization of MIP nanocomposite was developed using cyclic voltammetry (CV) and the electrochemical properties of 5-HT were studied use differential pulse voltammetry (DPV) technology in the 5HT solution. After optimization of preparation and measurement conditions on the designed sensor, the 5HT concentration range is 0.1 μM to 10 μM linearly, and the detection limit was 1 × 10-5 μM (S / N = 3). The wide concentration range and low detection limit were presented metal nanoparticles functionalized MIP with appropriate functional monomer have a great effect on the performance of the sensor. Furthermore, PATP-functionalized metal nanoparticles increase the conductivity and recognition of the prepared MIP electrochemical sensor to the quantification of 5-HT in biological samples with high selectivity and recovery.