The invention discloses a
caspase biosensor, application thereof and a detection method of
caspase activity. The
caspase biosensor comprises a
magnetic bead, a detection probe, an annular template,
DNA polymerase and a secondary primer, wherein the surface of the
magnetic bead is coated with
streptavidin; the detection probe comprises
a peptide substrate structural domain and
a DNA primer structural domain which are connected, the
peptide substrate structural domain is an
amino acid sequence, and the
DNA primer structural domain is a single-stranded
DNA sequence; the
peptide substrate structural domain contains a specific site, the specific site can be recognized and
cut by caspase, the specific site and a connecting site are separated by n amino acids, the connecting site is a joint of the
peptide substrate structural domain and the DNA primer structural domain, the
peptide substrate structural domain is connected with
biotin, the specific site is positioned between the
biotin and theconnecting site, and n is a natural number smaller than 10; and the DNA primer structural domain can be matched with the annular template, the
DNA polymerase and the secondary primer for a
branch rolling circle amplification reaction.