LAUSR

Abstract MXenes are attractive for various biosensors owning to their tunable versatile properties. Herein, Ti3C2 nanosheets (Ti3C2 NSs) were found to possess intrinsic peroxidase-like activity, and which could be enhanced by single-stranded DNA (ssDNA) adsorbed on the nanosheets. Hence, a simple label-free sensing strategy was developed for colorimetric detection of biomolecules, based on Ti3C2 NSs as a peroxidase mimic enzyme and ssDNA aptamer as an enzymatic activity enhancement factor along with a recognition substance for the target. In the presence of target biomolecules, the aptamers were desorbed from Ti3C2 NSs due to the specific binding of targets to aptamers, thus bringing about the decrease of catalytic activity. Thrombin (TB) as the model was determined by this constructed biosensor with a linear range of 1.0×10-11 to 1.0×10-8 M, and evaluated subsequently in the real blood samples with satisfactory results. This work highlights Ti3C2 MXenes as a nanomaterial mimic enzyme (called nanozyme) for monitoring biomolecules by target-specific recognition strategy.