Rapid and highly selective colorimetric detection of nitrite based on the catalytic-enhanced reaction of mimetic Au nanoparticle-CeO2 nanoparticle-graphene oxide hybrid nanozyme

The International Agency for Research cancer (IARC) has classified nitrite in Group 2A of probable carcinogens to human. Herein, we report on the rapid and selective colorimetric detection using a chemically modified gold nanoparticle (AuNP)-cerium oxide (CeO2) NP-anchored graphene (GO) hybrid nanozyme catalytic assay where acts as main oxidant/target analyte 3,3?,5,5?-tetramethylbenzidine (TMB) substrate. CeO2 NPs GO were synthesized separately incorporated in-situ, synthetic solution involving chemical reduction Au salt AuNPs. modification process aided adsorption AuNPs nanosheets, yielding highly AuNP–CeO2 [email protected] nanohybrid material. Under optimum experimental conditions, novel recognition was constructed which catalysed oxidation TMB presence prepared 2-(n-morpholino)ethanesulfonic acid-2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)propane-1,3-diol-tris(hydroxymethyl)aminomethane acetate (MES-BIS-TRIS-Trisma Ac)-citric acid buffer solution, pH 2. Nitrite quantitatively detected concentration dependent manner from 100 ?M 5000 with correlation coefficient 0.9961 limit 4.6 ?M. Selective confirmed by generation unique green colour reaction upon interaction redox cycle TMB. None several tested metal ions including H2O2 yielded positive response, thus demonstrating superior selectivity recognition. successfully applied tap water.