Copper-Loaded Nitrogen-Rich Mesoporous C3N6 Based Nanozymes for Calorimetric Detection of Glutathione and Glucose

Abstract

Biomolecular sensing is routinely implemented in healthcare industries for disease diagnostics. Copper nanoparticles efficiently mimic peroxidase, which is needed for efficient glucose and glutathione sensing. However, bare copper nanoparticles are toxic to humans, therefore, anchoring materials are needed to prevent health hazards. Among the carbon-based anchoring materials, graphene and its derivatives have already been implemented. However, due to poor C–Cu interaction, copper incorporation is inefficient in those systems, which necessitates the exploration of new suitable anchoring platforms. Nitrogen-rich carbon nitride C₃N₆ with edge nitrogen atoms and plenty of in-built vacancy sites in its lattice, apart from its facile synthesis, low cost, scalable production, and non-toxic nature; offers excellent candidature for this purpose. Cu-loaded mC₃N₆ (Cu-mC₃N₆) nanozyme is synthesized employing hard silica template SBA-15 and aminoguanidine hydrochloride and hydrated copper nitrate. First, peroxidase-like activity is investigated for Cu-mC₃N₆ nanozyme with chromogenic 3,3′,5,5′- tetramethylbenzidine (TMB) dye, followed by calorimetric detection of glutathione and glucose. Edge nitrogen active sites in the mC₃N₆ accommodate higher copper loading, resulting in enhanced peroxidase-like activity and glutathione biosensing performance with a low detection limit of 0.42 ppm. It is believed that the present research will inspire the development of future-generation nanozymes.