This study employs a guanine (G)-rich DNA sequence as the recognition element and integrates exonuclease III (Exo III) with a mismatch catalytic hairpin assembly (MCHA)-based cascade isothermal signal amplification strategy to construct a novel fluorescent DNA biosensor for the highly sensitive detection of kanamycin (Kana). In the presence of the target, the recognition element HP1 is unfolded by the target and forms a double-stranded HP1-HP2 structure with HP2. This structure is subsequently cleaved by Exo III, releasing the trigger strand of MCHA. The trigger strand binds to H1, which conta...
