Enhanced oxidase/peroxidase-like activities of aptamer conjugated MoS2/PtCu nanocomposites and their biosensing application

Hybrid composite materials are particularly useful and offer great opportunities for catalysis due to their multifunctionalities. Taking advantage of the high catalytic properties of bimetallic alloy nanoparticles, the large specific surface area and co-catalytic function of MoS2 nanosheets, we prepare a novel MoS2/PtCu nanocomposite with intrinsic high oxidase- and peroxidase-like activity. The preparation of MoS2/PtCu nanocomposites does not require organic solvents or high temperature. The introduction of single-layer MoS2 nanosheets not only improves porous PtCu nanoparticles with a fine dispersion, but also readily incorporates recognition elements. As a mimic oxidase, the independence of hydrogen peroxide shows the good biocompatibility of MoS2/PtCu for promising bioapplications. On the basis of oxidase-like activity, a novel colorimetric aptasensor (apt-MoS2/PtCu) was developed and its application in the colorimetric detection of cancer cells with different MUC1-protein densities was demonstrated. The as-prepared apt-MoS2/PtCu shows good sensitivity and selectivity to targeting cells. The proposed strategy will facilitate the utilization of MoS2-based nanocomposites with high oxidase/peroxidase activities in biotechnology, biocatalysis etc.