Recent Advances in Biosensors Based on Hybridization Chain Reaction and Silver Nanoclusters

Hybridization chain reaction (HCR) and DNA-templated silver nanoclusters (AgNCs) have emerged as powerful tools in biosensing. HCR enables cascade amplification through programmable DNA interactions, while DNA-AgNCs serve as transducing units with unique fluorogenic and electrochemical properties. Integrating these components into a hybrid sensor could significantly enhance sensing capabilities across various fields. Nonetheless, limited studies and the lack of systematic guidelines for HCR-AgNCs systems have hindered research progress, despite their potential. This review aims to address this gap by providing a comprehensive overview of HCR-AgNCs biosensors, facilitating further innovation in this field. The working principles, performance factors, and complementary features are discussed. Thereafter, reported HCR-AgNCs studies are assessed, emphasizing their distinct sensing mechanisms (e.g., fluorogenic, electrochemical), applications across various fields, and challenges in adopting the hybrid sensors. Drawing from the experience developing multiple HCR-AgNCs sensors, insights and guidelines for designing and developing HCR-AgNCs systems are provided for future researchers. Finally, prospective directions in HCR-AgNCs research, including multiplex assays and integration with emerging technologies, are explored to guide future advancements. The synergistic combination of HCR and AgNCs as a hybrid biosensor holds promise for addressing pressing challenges in healthcare, environmental monitoring, and beyond, paving the way for next-generation biosensing technologies.