An Au@NH2-MIL-125(Ti)-based multifunctional platform for colorimetric detections of biomolecules and Hg2+

In this report, a novel nanocomposite of highly dispersed Au nanoparticles deposited on NH2-MIL-125(Ti) was designed and proposed as a peroxidase-like mimic. Compared with individual Au nanoparticles and NH2-MIL-125(Ti), the peroxidase-like nanozyme exhibits enhanced peroxidase-like activity. Moreover, kinetic analysis reveals that the as-prepared nanozyme has lower Km values and stronger affinity towards both substrates than the natural horseradish peroxidase (HRP). The detection limits of the multifunctional platform for H2O2, cysteine and Hg2+ are down to 0.24 μM, 0.14 μM and 100 nM, respectively. This work provides rapid and sensitive colorimetric detection strategies for small biomolecules and Hg2+, which have great potential for application in biosensors and biotechnology.