A pure DNA hydrogel, consisting of two kinds of Y-scaffold nucleic acid subunits and the aptamer domain of ochratoxin A, undergoes a switchable gel-to-sol transition in the presence of ochratoxin A. The target molecule stimulated the disassembly of the DNA hydrogel to release the encapsulated HRP, which triggered the reaction of H2O2 and ABTS for dual signal amplification of colorimetric detection.
