Green synthesis of stable platinum nanoclusters with enhanced peroxidase-like activity for sensitive detection of glucose and glutathione

The sensitive and facile detection of the concentration of glucose and glutathione (GSH) is important for our health. In this work, lily polysaccharide (LP) stabilized platinum nanoclusters (Ptn-LP NCs) were prepared by a facile synthetic strategy where LP was used as a reducing agent and stabilizer. The successful preparation of 1–2 nm platinum nanoclusters (Pt NCs) inside of Ptn-LP NCs was confirmed using UV–Vis spectra, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Transmission electron microscopy (TEM), respectively. Furthermore, Ptn-LP NCs accelerated the catalytic oxidation of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue oxidized TMB (oxTMB) in the presence of hydrogen peroxide (H2O2), indicating their intrinsic peroxidase-like activity. The Vm values of TMB and H2O2 were 50.3 × 10−8 Ms−1 and 10.2 × 10−8 Ms−1, respectively, which were higher than those of other mimetic enzymes. The peroxidase-like property of Ptn-LP NCs was used to sensitively detect the concentration of glucose and glutathione (GSH). The detection limits of glucose and GSH were as low as 1.89 and 0.37 μM, the linear ranges of glucose and GSH were 2.5–1000 and 4–140 μM, respectively. The colorimetric method was successfully applied to detect GSH concentration in human serum. This method has great potential application in bio-related detection in the future.