Immuno‐Rolling Circle Amplification (Immuno‐RCA): Biosensing Strategies, Practical Applications, and Future Perspectives

Abstract In the rapidly evolving field of life sciences and biomedicine, detecting low‐abundance biomolecules, and ultraweak biosignals presents significant challenges. This has spurred a rapid development of analytical techniques aiming for increased sensitivity and specificity. These advancements, including signal amplification strategies and the integration of biorecognition events, mark a transformative era in bioanalytical precision and accuracy. A prominent method among these innovations is immuno‐rolling circle amplification (immuno‐RCA) technology, which effectively combines immunoassays with signal amplification via RCA. This process starts when a targeted biomolecule, such as a protein or cell, binds to an immobilized antibody or probe on a substrate. The introduction of a circular DNA template triggers RCA, leading to exponential amplification and significantly enhanced signal intensity, thus the target molecule is detectable and quantifiable even at the single‐molecule level. This review provides an overview of the biosensing strategy and extensive practical applications of immuno‐RCA in detecting biomarkers. Furthermore, it scrutinizes the limitations inherent to these sensors and sets forth expectations for their future trajectory. This review serves as a valuable reference for advancing immuno‐RCA in various domains, such as diagnostics, biomarker discovery, and molecular imaging.