Protein-responsive rolling circle amplification as a tandem template to drive amplified transduction of fluorescence signal probes for highly sensitive immunoassay.

Proximity binding-induced DNA assemblies possessing outstanding flexibility and diversity can provide great accessibility for output translation of amplifiable DNA probes or directly detectable signals. Based on a novel protein-responsive DNA assembly constructed via proximity binding-initiated rolling circle amplification (RCA), we present a sensitive and specific fluorescence resonance energy transfer (FRET) strategy for the immunoassay of mucin 1 (MUC1). The resultant RCA product containing numerous and continuous repeats as the tandem template accelerates the transduction of signal probes through the disassembly of triple-helix stem structure (THSS), achieving a significantly amplified FRET signal readout.