Visual and quantitative detection of glucose based on the intrinsic peroxidase-like activity of CoSe2/rGO nanohybrids

- The CoSe2/rGO peroxidase mimetics nanohybrids were successfully synthesized.
- The nanohybrids displayed higher binding affinity for H2O2 than HRP.
- The detection limit of H2O2 and glucose are 0.23 and 0.553 μM, respectively.
- The method is applicable for the detection of glucose concentration in real samples.

Glucose concentration in human body is a significant indicative for diabetes screening, so it is very significant to develop rapid and sensitive methods for glucose detection. Herein, CoSe2/reduced graphene oxide (CoSe2/rGO) nanohybrids were synthesized via a simple and convenient hydrothermal method, and also their morphologies and compositions were systematically characterized. The CoSe2/rGO nanohybrids were found to possess an intrinsic peroxidase-like activity and can effectively catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2) accompanied with a blue color change. The catalytic activity of CoSe2/rGO nanohybrids is matched with the typical Michaelis-Menten kinetics and highly dependent on reaction time, pH, incubation temperature, and H2O2 concentration. The peroxidase-like CoSe2/rGO nanohybrids were successfully applied for the detection of H2O2 and glucose with the detection limit as low as 0.23 μM and 0.553 μM, respectively. Furthermore, some other carbohydrates, such as lactose, sucrose, galactose and fructose have no interferences with the detection of glucose. The detection platforms for glucose developed in the present work not only confirmed that the CoSe2/rGO nanohybrids possess intrinsic peroxidase-like activity but also showed great potential applications in varieties of simple, robust, and easy-to-make analytical approaches in the future.

Schematic illustration of colorimetric detection of H2O2 and glucose by CoSe2/RGO nanohybrids as peroxidase mimics.79