Boosting the peroxidase-like activity of Pt nanozymes by a synergistic effect of TiC nanosheets for dual mechanism detection.

Nanozymes show great promise in bioanalysis and therapeutics, which largely rely on high catalytic efficiency and selectivity. Inspired by the interfacial electronic interaction between noble metals and transition metal carbides, Pt nanozymes are modified with TiC MXene nanosheets to construct TiC/Pt hybrids with synergistically enhanced catalytic activity. Although TiC does not have oxidase and peroxidase-like activity, it can greatly selectively enhance the peroxidase-like activity of Pt nanozymes. Near-infrared irradiation can further increase specifically the peroxidase-like activity of TiC/Pt. The optimal peroxidase-like activity of TiC/Pt is 6 times higher than Pt in the dark and 7.9 times higher than Pt under illumination. This catalytic enhancement is attributed to the interplay of the strong interfacial electron effect and unique photothermal effect of TiC. Using the superior peroxidase-like activity of TiC/Pt, dual mechanism colorimetric methods based on cascade reaction and inhibitory effect are developed for specific detection of glucose and glutathione with a limit of detection of 1.0 μM and 0.0089 μM, respectively. Our work provides an effective means to improve the catalytic activity and selectivity of nanozymes by introduction of an ideal supporter, which will be of value for the design of efficient nanozymes.