Next-generation biosensing with perovskite quantum dots: From material engineering to rapid and multiplexed detection of infectious pathogens

Halide perovskite quantum dots (PQDs) enable sensitive detection of bacterial and viral pathogens in clinical, food, and environmental samples. Key technical advances include dual-mode lateral-flow assays combining fluorescence and electrochemiluminescence for Salmonella detection in milk and juice, lead-free Cs₃Bi₂Br₉-based photoelectrochemical sensors offering sub-femtomolar miRNA sensitivity with extended serum stability, and machine-learning-assisted fluorescent arrays achieving complete discrimination of multiple bacteria in tap water. Major challenges remain aqueous-phase degradation, lead-related toxicity of CsPbBr₃ PQDs, and regulatory barriers to clinical use. Although surface passivation extends stability for weeks, Pb²⁺ release from lead-based compositions typically exceeds permitted levels for parenteral administration, whereas bismuth-based PQDs already meet current safety standards without additional coating. Further progress requires scalable lead-free formulations, robust long-term stability under physiological conditions, and standardized validation protocols. Integration with portable detection systems, nucleic-acid amplification techniques, and microfluidic platforms is essential for practical point-of-care implementation. This review article systematically covers the intersection of PQD material engineering and biosensing for viral and bacterial detection. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.