Advances in quantum dot-based fluorescent biosensors for enzyme detection: mechanistic insights and applications in...

It is imperative to develop precise detection tools for enzymes, as key biomarkers in disease pathogenesis, to fuel progress in clinical diagnostics and personalized medicine. Quantum dots (QDs), with exceptional photostability, size-tunable emission, and multiplexing capabilities, have emerged as transformative nanomaterials for designing next-generation fluorescent biosensors. Recently, numerous researchers have employed QD-based fluorescent biosensors for detecting or real-time monitoring enzymes for disease diagnosis and treatment, which possess excellent photostability, regulable fluorescence emission, strong multi-channel detection capability, and high sensitivity. This review delves into enzyme-responsive QD-based fluorescent biosensors, dissecting the mechanisms driving enzyme activity sensing and exploring their translational applications in biomedical diagnostics, inhibitor screening, and in vitro or vivo sample analysis. An overview of innovative detection strategies leverages the optoelectronic properties of QDs for ultrasensitive and real-time monitoring of enzyme activity, such as Förster resonance energy transfer and the inner filter effect. Their diagnostic and therapeutic applications were also explored in addressing high-burden diseases such as cancer and diabetes. Meanwhile, this review systematically summarizes the core advantages of these biosensors, analyzes their current limitations, and outlines novel prospects as well as key challenges in their respective application fields, such as green synthesis, artificial intelligence, and biological imaging detection. It underscores their promise in nanobiotechnology and healthcare, laying a cornerstone for clinical diagnosis and therapy while constructing an innovative interdisciplinary research framework.