A dual amplified gold nanoparticle‐based biosensor for ultrasensitive and selective detection of fibrin

Abstract Ultrasensitive, selective, and non‐invasive detection of fibrin in human serum is critical for disease diagnosis. So far, the development of high‐performance and ultrasensitive biosensors maintains core challenges for biosensing. Herein, we designed a novel ribbon nanoprobe for ultrasensitive detection of fibrin. The probe contains gold nanoparticles (AuNPs) that can not only link with homing peptide Cys‐Arg‐Glu‐Lys‐Ala (CREKA) to recognize fibrin but also carry long DNA belts to form G‐quadruplex‐based DNAzyme, catalyzing the chemiluminescence of luminol–hydrogen peroxide (H 2 O 2 ) reaction. Combined with the second amplification procedure of rolling circle amplification (RCA), the assay exhibits excellent sensitivity with a detection limit of 0.04 fmol L −1 fibrin based on the 3‐sigma. Furthermore, the biosensor shows high specificity on fibrin in samples because the structure of antibody‐fibrin‐homing peptide was employed to double recognize fibrin. Altogether, the simple and inexpensive approach may present a great potential for reliable detection of biomarkers.