CRISPR-Cas12a accessory cleavage activity triggering electrochemiluminescence biosensor for adenosine triphosphate detection

Encouraged by the remarkable editability, sequence-specificity, trans-cleavage peculiarity of the CRISPR-Cas12a, the concept of CRISPR-Cas12a accessory cleavage activity triggering electrochemiluminescence (ECL) biosensor for adenosine triphosphate (ATP) detection was proposed. The ATP aptamer was elaborately designed to stimulate the CRISPR-Cas12a activity for non-specifical trans-cleavage of the single-stranded DNA (ssDNA) modified L-Cys@Fe3O4 MNPs. Those sheared ssDNA fragments and the hatched capture DNA on the electrode surface folded into double-helix structures for embedding of tris (2, 2´-bipyridine) dichlororuthenium (Ⅱ) [Ru(bpy)23+] molecules to trigger “turn-on” signal. Specific conjugation of ATP aptamer to ATP surpassed base complementary pairing with the CRISPR-Cas12a, which inhibited CRISPR-Cas12a accessory cleavage activity and interfered with stability of the Cas12a-crRNA-ATP aptamer complex causing the “on-off” signal transformation. Thanks to the efficient signal-amplification produced by the editable CRISPR-Cas12a, this biosensor was performed for the specific and precise detection of ATP with the detection limit of 1.9 nM. Acceptable results showcase this CRISPR-Cas12a assisted ECL sensing strategy will open up a new pathway for more related bioanalysis.