Optimization of Sensor Based on Molecularly Imprinted Polymeric Nanoparticles for Detection of Dipicolinic Acid as a Biomarker in Bacterial Spores

A unique sensitive electrochemical Molecularly Imprinted Polymer (MIP) sensor was fabricated using a Glassy Carbon Electrode (GCE) in phosphate buffer solution (pH 7.0) and cyclic voltammetry in the presence of dipicolinic acid (DPA) as a template molecule. In addition, gold nanoparticles (AuNPs) were used to modify the electrode’s surface. AuNPs were roughly spherical in shape and irregular in distribution. The diameter of the nanoparticles was in the range of 14-30 nm. The cyclic voltammograms confirmed that the MIP-modified electrode had higher sensitivity than the non-modified electrode due to the presence of specific binding sites. The analysis of AuNPs/MIP modified electrodes in the presence of various similar compounds, such as Dinicotinic acid, Glucose, Ascorbic acid, and Phenylalanine confirmed the applicability of modified electrodes for recognition of DPA. High selectivity and sensitivity were achieved using the AuNPs/MIP modified electrode for the detection of DPA in the concentrations of 0 and 10-2 M, with a low detection limit of 1.58 × 10-8 M and response time 20 s. The fabricated sensor was selective, sensitive, controllable, and easy to operate without the need for any toxic or dangerous by-products.