Carbon Dots for Sensor Applications: Synthesis Strategies and Detection Mechanisms - A Mini Review

Abstract

Carbon dots (CDs) have emerged as promising zero-dimensional carbon-based nanomaterials due to their unique optical, chemical and electronic properties, enabling their application in diverse sensing platforms. Compared with conventional semiconductor quantum dots, CDs offer advantages including low toxicity, excellent stability, biocompatibility and facile surface functionalization. However, the physicochemical properties and sensing performance of CDs are highly dependent on synthesis strategies, precursor selection and reaction conditions. This review provides an overview of recent advances in CDs synthesis approaches and their influence on structural characteristics and sensing capabilities. The major synthesis routes, including top-down methods such as laser ablation and electrochemical oxidation, as well as bottom-up approaches including hydrothermal, solvothermal, microwave-assisted and biomass-derived synthesis, are discussed in relation to their effects on particle size, surface functionality, optical properties and electronic behaviour. Furthermore, the applications of CDs-based sensing platforms in fluorescence sensing, environmental monitoring, biosensing and electrochemical detection are reviewed, emphasizing the relationship between CDs characteristics and analytical performance. Despite significant progress, challenges associated with synthesis reproducibility, scalability and practical implementation remain important considerations. Future development of CDs-based sensing technologies requires rational synthesis design and integration with advanced sensing devices to achieve reliable, sustainable and high-performance analytical platforms.