A Chemiluminescent Method for the Detection of H₂O₂ and Glucose Based on Intrinsic Peroxidase-Like Activity of WS₂ Quantum Dots.

Currently, researchers are looking for nanomaterials with peroxidase-like activity to replace natural peroxidase enzymes. For this purpose, WS₂ quantum dots (WS₂ QDs) were synthesized via a solvothermal method, which improved the mimetic behavior. The resulting WS₂ QDs with a size of 1⁻1.5 nm had a high fluorescence emission, dependent on the excitation wavelength. WS₂ QDs with uniform morphology showed a high catalytic effect in destroying H₂O₂. The peroxidase-like activity of synthesized nanostructures was studied in H₂O₂ chemical and electrochemical reduction systems. The mimetic effect of WS₂ QDs was also shown in an H₂O₂⁻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, H₂O₂ is one of the products which can be determined. Under optimum conditions, H₂O₂ can be detected in the concentration range of 0⁻1000 nmol·L, with a detection limit of 2.4 nmol·L. 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, with a limit of detection (3S) of 4.2 nmol·L.