Peroxidase Mimicking VO Nanozymes as the Spectrophotometric Sensor for the Determination of Glucose in Human Serum Sample Employing New Chromogenic Co-Substrates

Enzyme mimics are developed as an alternative to natural enzymes to overcome the inherent limitations of natural enzymes. Among different types of enzyme mimics, nanozymes gained importance due to their tuneable catalytic properties. In this article, we discuss the peroxidase behaviour of different shape VO nanoparticles (NPs). A simple spectrophotometric method is presented for the quantification of glucose and HO using novel chromogenic reagents. The NPS are characterized with SEM, DLS, EDS, FTIR and XRD. From SEM images, based on the morphology, the NPs were named as vanadium nanosheets (VNShs), nanoflowers (VNFws) and nanospheres (VNSps). The average crystalline size of the nanoparticles is calculated using XRD data from Scherrer’s equation and Williamson-Hall plot and was found to be 45.42, 45.7nm for VNShs, 29.14, 32.5nm for VNFws, and 39.83, 38.7nm for VNSps respectively. The linearity of glucose was ranged from 0.0289 to 0.925mM for HRP, VNShs VNFws, and 0.925 to 0.0528mM for VNSps. The HO was in good linear range between 0.003 to 1.9383mM in both rate and fixed time method for all nanozymes and HRP. For recovery study 10µL serum sample was directly used without dilution. The K values were found to be 1.6239 mM for HRP, 0.7843 mM for VNShs, 0.6514 mM for VNFws, ands 0.6398 mM for VNSps concluding that NZs have better affinity towards substrate molecule. The detection limit and quantification limits were found to be 0.0548mM and 0.1662mM for HRP, 0.066mM and 0.2002mM for VNShs, 0.0425mM and 0.1287mM for VNFws and 0.1474mM and 0.4465mM for VNSps.