The invention relates to the field of
veterinary drug residue detection, in particular to a
fluorescence sensor based on
DNA molecular machine mediated split Cas12a and application of the
fluorescence sensor to
ofloxacin detection, the
fluorescence sensor comprises a
system A, a
system B and a
system C. According to the final concentration of each system, the system A comprises an AP / CP double-stranded compound and a 20 mM
Tris-HCl
buffer solution 1, the system B comprises a double-stranded compound, an sRNA probe and a 10 mM
Tris-HCl
buffer solution 2, and the system C comprises
a DNA molecular machine mediated split Cas12a. The system C comprises a Cas12a / hRNA compound, a pDNA / psG43
signal probe, ThT and a 20 mM
Tris-HCl
buffer solution; aP in the AP / CP double-chain compound is an
aptamer of
ofloxacin, and AP and CP in the AP / CP double-chain compound are paired and connected through complementary base
pairing; the sequences of AP, CP, PS, SS, sRNA, hRNA, pDNA and psG43 are respectively as shown in SEQ ID NO.1-SEQ ID NO.8. The invention also discloses a kit for detecting the content of the
protein. According to the application, the
nucleic acid aptamer of
ofloxacin is utilized, based on
a DNA molecular machine and SCas12a as a
signal amplification technology and sulfo-modified G43 as a fluorescent
signal probe, even if the content of ofloxacin in a sample is extremely low, detection can be accurately realized.