Programming an antibody-peptide sandwich procedure for selectivity and ultrasensitive detection of fibrin using double-stranded DNA (dsDNA) hemp string probe

A novel, highly sensitive and selective sandwich-like enzyme-linked immunoassay procedure for the detection of fibrin was developed. Firstly the monoclonal anti-fibrinogen which was coated on the surface of microtiter plate can interact with fibrin, and the probe of double-stranded DNA (dsDNA) hemp string containing the homing peptide can secondarily recognize the fibrin. On the other hand, combined with the hybridization chain reaction (HCR), the terminal of dsDNA can be folded to a long G-quadruplex-hemin DNAzyme, which can catalyze luminol–H2O2 system to generate strong chemiluminescence signal. Under the optimal experimental conditions, the assay showed a linear toward fibrin concentration in the range of 0.14–72.5 pM with detection limit of 0.04 pM. Because of high selectivity and ultra-sensitivity, the designed procedure provides great potential for applications in medical diagnosis.