DNA-stabilized bimetallic nanozyme and its application on colorimetric assay of biothiols

This paper reports a facile synthesis of bimetallic AuxPty nanozyme using C-rich oligonucleotide as the nucleation template, with high peroxidase-like activity and thiophilicity associated with the ratio of x:y. The efficient Au2Pt1 nanozyme possesses highly peroxidase mimicking activity with the Km value of 0.088 mM toward 3,3′,5,5′-tetramethylbenzidine and 196 mM toward hydrogen peroxide. It is the first report to explore colorimetric assays for biothiols with high sensitivity and selectivity against non-thiol-containing amino acids, on the basis of thiol-induced inhibition of peroxidase-like activities of metal nanoparticles. By using Au2Pt1 nanozyme, the limit of detection (LOD) is 3.5 nM for cysteine and 1.6 nM for homocysteine. This DNA-stabilized bimetallic AuxPty nanozyme shows a promising application in quantitative detection of biothiols in biological fluids.