Quantum dot (QD)-based biosensors have become a promising platform for biomedical diagnostics, particularly for early disease detection, where conventional immunoassays often struggle with low sensitivity, photobleaching, and poor optical penetration in biological tissues. QDs overcome these limitations through exceptional photostability, size-dependent emission tunability, and high quantum yield, enabling reliable detection even at ultralow biomarker levels. Their surface chemistry can be precisely engineered to attach antibodies, aptamers, peptides, or nucleic acids, supporting a wide range of selective and multiplexed sensing formats. QDs capable of near-infrared (NIR) emission further enhance clinical applicability by reducing tissue autofluorescence and improving in vivo imaging depth for real-time molecular tracking. This review highlights recent advances in QD-based fluorescent, photoelectrochemical, and electrochemiluminescent biosensors, emphasising their operating principles, analytical performance, and utility in detecting pathogens, cancer biomarkers, metabolites, and other clinically relevant targets. Challenges, including toxicity, biocompatibility, and biodistribution, are discussed alongside emerging solutions such as surface passivation, cadmium-free compositions, and biocompatible coatings. Unlike existing reviews, this article provides a mechanistic and integrated perspective by linking quantum dot surface engineering with sensing mechanisms and their clinical translational relevance, offering a unified framework for next-generation diagnostic development.
Patra et al. (Thu,) studied this question.