Ultra-small biocompatible jujube polysaccharide stabilized platinum nanoclusters for glucose detection

Abstract

The development of noble ultra-small biocompatible Pt nanoclusters (Pt NCs) for glucose detection has been drawing great attention. Herein, ultra-small biocompatible jujube polysaccharide (JP) stabilized platinum nanoclusters (Pt_n-JP NCs) are prepared using natural JP as a reducing and solubilizing agent. Pt_n-JP NCs were studied for the colorimetric detection of glucose. Pt_n-JP NCs (n = 50, 200 and 400) had an average particle diameter of 1–2 nm. Particularly, the measurements of hydrodynamic sizes of Pt_n-JP NCs indicated that they maintained good stability in solution for one week. Pt₂₀₀-JP NCs showed good biocompatibility, and were not toxic against HeLa cells at a high concentration of 400 μg mL⁻¹. Furthermore, Pt₂₀₀-JP NCs catalyzed the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) with H₂O₂ to produce blue oxidized TMB (oxTMB). This reaction followed typical Michaelis–Menten kinetics. More importantly, the glucose concentration could be sensitively detected by the color change, and this process was not interfered by other sugars. The linear range for glucose concentration was from 0.01 to 1 mM with a detection limit of 5.47 μM. The glucose concentrations of real samples of serum using Pt₂₀₀-JP NCs were 9.2, 4.9 and 6.5 mM, respectively. The prepared Pt_n-JP NCs have great potential in various biomedical detection methods.