Ultra-small and biocompatible platinum nanoclusters with peroxidase-like activity for facile glucose detection in real samples.

The highly sensitive glucose detection based on the peroxidase-like properties of nanoclusters has been gained great interest. In this work, Pericarpium Citri Reticulatae polysaccharide (PCRP) stabilized platinum nanoclusters (Pt-PCRP NCs) were prepared by a green method in which potassium tetrachloroplatinate and PCRP were simply mixed without addition of other agents. Platinum nanoclusters (Pt NCs) had ultra-small size of 1.26 ± 0.34 nm. The hydrodynamic size of Pt-PCRP NCs was 29.7 nm, and zeta potential of which was -12.0 mV. Pt-PCRP NCs showed high biocompatibility toward HeLa cells and red blood cells. In addition, Pt-PCRP NCs catalyzed the decomposition of HO to produce •OH, which further oxidized colorless 3,3'5,5'-tetramethylbenzidine (TMB) to blue oxidized 3,3',5,5'-tetramethylbenzidine (oxTMB), exhibiting peroxidase-like property. The kinetics followed the Michaelis-Menten equation. More importantly, the colorimetric method for glucose detection using Pt-PCRP NCs had high selectivity and low detection limit for 0.38 μM. The established method based on Pt-PCRP NCs was used to precisely detect glucose detection in human serum, saliva, and sweat. Taken together, the prepared ultra-small and biocompatible Pt-PCRP NCs have good potential glucose applications in clinical diagnosis in the future.