Fluorescent Carbon Dots Illuminate Hydrogen Peroxide Detection: A Promising Approach

Hydrogen peroxide ($H_{2}O_{2}$) is an oxidant widely used in industrial and biomedical applications that requires a sensitive and selective quantification method. Despite being one of the most used methods for detecting this oxidant, enzyme-based reactions still exhibit low-cost efficiency and pose high environmental hazards. Optical biosensors have emerged as an attractive alternative, offering potential advantages such as rapid response time and ease of operation. Carbon dots (CDs) are a type of carbon-based nanoparticles that are particularly appealing for this purpose because of their low-cost synthesis procedures and favorable chemical and optical properties. In this study, fluorescent CDs were synthesized via a microwave-assisted method using urea, L-histidine, and citric acid as precursors. The optical properties of the CDs were characterized using UV-Vis and fluorescence spectroscopy. The CDs exhibited a fluorescence sensing range between 1 mM to 50 mM, with a limit detection (LOD) for $H_{2}O_{2}$ of 0.1 mM. The selectivity of the CDs was tested in the presence of various interferents, and the results confirmed their potential for further applications, particularly in metabolite quantification and biological processes. Overall, the low-cost synthesis procedure and favorable properties of the CDs make them a promising candidate for $H_{2}O_{2}$ detection and other biosensing applications.