A facile preparation of FePt-loaded few-layer MoS nanosheets nanocomposites (F-MoS-FePt NCs) and their application for colorimetric detection of HO in living cells.

Background: Rapid and sensitive detection of HO especially endogenous HO is of great importance for series of industries including disease diagnosis and therapy. In this work, uniform FePt nanoparticles are successfully anchored onto Few-layer molybdenum disulfide nanosheets (F-MoS NSs). The powder X-ray diffraction, transmission electron microscopy, UV-Vis spectra and atomic force microscopy were employed to confirm the structure of the obtained nanocomposites (F-MoS-FePt NCs). The prepared nanocomposites show efficient peroxidase-like catalytic activities verified by catalyzing the peroxidation substrate 4,4'-diamino-3,3',5,5'-tetramethylbiphenyl (TMB) with the existence of HO.

Results: The optimal conditions of the constructed colorimetric sensing platform is proved as 35 °C and pH 4.2. Under optimal catalytic conditions, the detection limit for HO detection reaches 2.24 μM and the linear ranger is 8 μM to 300 μM. Furthermore, the proposed colorimetric sensing platform was successfully utilized to detect the intracellular HO of cancer cells (MCF-7).

Conclusions: These findings indicated that the F-MoS-FePt-TMB-HO system provides a potential sensing platform for hydrogen peroxide monitoring in living cells.