Effect of Guanosine Triphosphate on Peroxidase-like Activity of Mo-Zn Single-atom Nanozymes and Its Portable Detection
Mo-Zn single-atom nanozymes (Mo-Zn SANs) with peroxidase (POD)-like activity was prepared by wet chemical-pyrolysis method. The effects of seven molecules,namely guanosine triphosphate (GTP),adenosine triphosphate (ATP),cytidine triphosphate (CTP),uridine triphosphate (UTP),guanosine diphosphate (GDP),guanosine monophosphate (GMP) and guanosine (G),on the POD-like activity of Mo-Zn SANs were investigated. Among them,GTP combined with Mo-Zn SANs to form a new complex through electrostatic and coordination interactions. The introduction of negatively charged phosphate groups increased the affinity for the substrate 3,3',5,5'-tetramethyl benzidine (TMB),significantly enhancing the catalytic activity of Mo-Zn SANs. However,other nucleotides such as ATP,CTP and UTP had little effect on the POD-like activity of Mo-Zn SANs. Based on this principle,a colorimetric sensor with smartphone-assisted signal output was constructed for portable detection of GTP. The method exhibited good sensitivity and selectivity for detecting GTP,and could distinguish GTP from its structural analogues. Under optimized conditions,the linear detection range of GTP was 1-10μmol/L and the limit of detection was 0.97μmol/L,meeting the requirements for detection of biological samples.