In-situ generation of nanozymes by natural nucleotides: a biocatalytic label for quantitative determination of hydrogen peroxide and glucose

Four natural nucleotides including 5′-cytidine monophosphate (CMP), 5′-thymidine monophosphate (TMP), guanosine monophosphate (GMP) and 5′-adenosine monophosphate (AMP) were employed to modulate the coordination environment and the valence state of PtCl42−. This is the first report that natural nucleotides have the ability to produce highly active Pt nanoclusters. The latter are shown to act as peroxidase mimetics. Both the size distribution and the charge state of Pt-nucleotide nanozymes vary with the chemical structures of nucleotides, thereby contributing to distinct enzyme-like activities. By adopting Pt-CMP as a signal amplifier, a photometric assay was well-established for quantitative determination of glucose. The assay is based on the oxidation of glucose by glucose oxidase. The oxidation product (H2O2) is detected at 652 nm via the Pt-CMP-catalyzed oxidation of 3,3′,5,5′-tetramethylbenzidine with H2O2. Response is linear in the 5 to 100 μM glucose concentration range, and the limit of detection is 0.12 μM (at S/N= 3). The method excels by a low signal background, high sensitivity, and low consumption of energy and materials.