MoS2 nanosheets with peroxidase mimicking activity as viable dual-mode optical probes for determination and imaging of intracellular hydrogen peroxide

Abstract

The authors describe a dual-mode (colorimetric-fluorometric) nanoprobe for HO that was fabricated by covering molybdenum disulfide nanosheets (MoS NS) with ortho-phenylenediamine (OPD). The probe (OPD-MoS NS) was applied to the optical determination of HO, to the quantitation of cell numbers, and to the detection of intracellular concentrations of HO. Oxidation by HO leads to a colored and fluorescent product (oxidized OPD) with absorption/excitation/fluorescence peaks at 450/450/557 nm. The nanoprobe can detect HO in down to 500 nM concentrations, and HeLa cells at levels of 100 cells mL. The detection limit for intracellular HO is in the 5.5 to 12.6 μM concentration range when the method is applied to cells at levels of 10-10 cells mL. Due to its good biocompatibility and easy cell uptake, the nanoprobe also permits sensitive fluorometric imaging of intracellular HO. It can also comparatively discriminate the change of intracellular oxidation state in living cancerous and normal cells. Graphical abstract Editor, we provided image with high resolution. Please find it in a folder name "MIAC-D-18-00081" in the FTP site. A dual-mode (colorimetric-fluorometric) detection nanoplatform based on OPD-modified MoS nanosheets is used to quantitatively detect HO, cell numbers and intracellular HO. The MoS nanoprobes also permit sensitive fluorescence imaging of intracellular HO, and can discriminate intracellular oxide states in living cancerous and normal cells.

Plasma-Assisted Controllable Doping of Nitrogen into MoS2 Nanosheets as Efficient Nanozymes with Enhanced Peroxidase-Like Catalysis Activity

“…Furthermore, a characteristic peak at 455 cm –1 could be observed from the inset spectra, which can be assigned to the Mo–S vibration . In addition, a characteristic peak at 600 cm –1 corresponding to the Mo–N vibration could be observed for the N-doped MoS 2 , , indicating the successful doping of N elements into MoS 2 nanosheets.…”

“…Furthermore, a characteristic peak at 455 cm −1 could be observed from the inset spectra, which can be assigned to the Mo−S vibration. 42 In addition, a characteristic peak at 600 cm −1 corresponding to the Mo−N vibration could be observed for the N-doped MoS 2 , 43,44 indicating the successful doping of N elements into MoS 2 nanosheets. The surface chemical composition and elemental valence states of the developed N-doped MoS 2 were investigated by Xray photoelectron spectroscopy (XPS), taking MoS 2 as the comparison (Figure 2).…”

Photodynamically Functionalized CoP/MoS2 Nanocomposites with Antibacterial Activity

“…10 Compared with graphene, MoS 2 has higher sensitivity and can be used as high-quality nanoprobes for optical sensing, 11 biological imaging, 12 cancer treatment, 13 antibacterial activity, 14,15 and wound healing. 16,17 MoS 2 is recommended for photothermal therapy of cancer treatment 18,19 and antibacterial activity 20 ever, the narrow band gap (1.9 eV) of MoS 2 makes it easier to recombine photogenerated carriers, greatly limiting the antimicrobial activity of MoS 2 . The combination therapy based on sterilization is expected to be an effective strategy to enhance photocatalytic antibacterial efficiency.…”

Colorimetric determination of cysteine and copper based on the peroxidase-like activity of Prussian blue nanocubes

“…In the emerging development of nanotechnology, many novel nanomaterials have been synthesized with intrinsic mimic-like activity, behaving as mimicking enzymes in the place of established enzymes. A variety of nanomaterials, such as metals (Cu 2+ ), 30 bimetals (Au@Pt, Au@Pd), 31,32 metal oxides (CuO, CeO 2 ), 33,34 metal suldes (MoS 2 ), 35 metal organic frameworks MOFs, 36 carbon-based nanomaterials, [37][38][39][40] Au nanoclusters 41 and TiO 2 nanotube arrays, 42 have been proved to possess peroxidase-mimicking activity. Among these, Prussian blue (PB) based materials have been extensively applied in different elds, such as electrochemical sensors, [43][44][45] ber optic gas sensors, 46 the oxygen reduction reaction, 47 and lateral ow assays.…”