Development of n-nitrosamine sensor based on graphene screen-printed electrode modified with palladium nanoparticles coated with molecularly imprinted polymer

This research involves the creation of a compact voltammetric sensor for the sensitive and selective determination of N-nitrosodiphenylamine (NDPhA) using screen-printed graphene electrodes modified with a molecularly-imprinted polymer (MIP) coating on a palladium nanoparticle core (PdNPs@MIP/SPGrE). A new approach is also proposed for the 3D printing of NDPhA on a PdNPs surface. PdNPs were first synthesized by chemical reduction using sodium borohydride. The core-shell polymer can then be successfully created by continuously coating the surface of the PdNPs with poly(vinylpyrrolidone) and terminating with an MIP consisting of poly (N-Isopropylacrylamide)-co-trimethylolpropane trimethyl acrylate. Morphological, structural, and electrochemical characterization revealed that the prepared microscopic, spherical PdNPs@MIP uniformly possessed high electrocatalytic capability and a specific surface area with a large number of NDPhA MIP sites. In this study, compact NDPhA MIP sensors were created by coating the SPGrE substrate with PdNPs@MIP. The quantitative analysis was performedby linear sweep anodic stripping voltammetry (LSASV) using a deposition potential of +0.02 V for 60 s. The linearity range for the NDPhA measurement is 0.01 - 0.1 uM (r2=0.996) and 0.1 - 100 [M (12 =0.992), with a corresponding sensitivity range of 51.935 and 0.821 (uA s) [M-1, respectively. The system provides reliable accuracy of %RSD 1.67% with a minimum detection limit of (3Sb, n =3) of 0.0013 HM. The intraday and inter-day accuracy (%bias) is determined by the certified reference material (CRM) which were -0.74% and -1.01%, respectively. This research demonstrates the successful application of a compact sensor fabricated to measure NDPhA in beverage and synthetic samples. The compact NDPhA the molecular-imprinted sensor can serve as an alternative approach to food quality control.