A chemiluminescent method for the detection of H 2 O 2 and glucose based on intrinsic peroxidase-like activity of WS 2 quantum dots

Abstract

Currently, researchers are looking for nanomaterials with peroxidase-like activity to replace natural peroxidase enzymes. For this purpose, WS 2 quantum dots (WS 2 QDs) were synthesized via a solvothermal method, which improved the mimetic behavior. The resulting WS 2 QDs with a size of 1�1.5 nm had a high fluorescence emission, dependent on the excitation wavelength. WS 2 QDs with uniform morphology showed a high catalytic effect in destroying H 2 O 2 . The peroxidase-like activity of synthesized nanostructures was studied in H 2 O 2 chemical and electrochemical reduction systems. The mimetic effect of WS 2 QDs was also shown in an H 2 O 2 �rhodamine B (RB) chemiluminescence system. For this aim, a stopped-flow chemiluminescence (CL) detection system was applied. Also, in order to confirm the peroxidase-like effect of quantum dots, colorimetry and electrochemical techniques were used. In the enzymatic reaction of glucose, H 2 O 2 is one of the products which can be determined. Under optimum conditions, H 2 O 2 can be detected in the concentration range of 0�1000 nmol·L � 1 , with a detection limit of 2.4 nmol·L � 1 . Using this CL assay, a linear relationship was obtained between the intensity of the CL emission and glucose concentration in the range of 0.01�30 nmol·L � 1 , with a limit of detection (3S) of 4.2 nmol·L � 1 © 2019 by the authors