On the extraction of MoO _x photothermally active nanoparticles by gel filtration from a byproduct of few-layer MoS₂ exfoliation

Abstract

Gel filtration is a versatile technique employed for biological molecules and nanoparticles, offering their reproducible classification based on size and shape. Colloidal nanoparticles are of significant interest in biomedical applications due to a large number of solution-based bioconjugation procedures. Nevertheless, the inherent polydispersity of the nanoparticles produced by various techniques necessitates the employment of high yield separation and purification techniques. Here we demonstrate the employment of gel filtration on non-stoichiometric plasmonic MoO x nanoparticles, prepared by an oxidation process during liquid-phase exfoliation of few-layer MoS2 nanosheets. This resulted in the separation of two types of MoO x particles, in the form of two different chromatographic fractions. They showed different sizes, morphological and optical properties. The fraction containing smaller particles with diameters of 1–4 nm, exhibited an increased absorbance peak in the near IR region and responded with a significant temperature increase to laser irradiation at the wavelength close to the maximal absorption. The fraction with the larger particles from 3 up to 10 nm, showed weak photoluminescence and a preferred orientation upon the deposition on a planar substrate. However, it had no absorbance in the near IR compared to the former fraction. According to our knowledge, this is the first time that the gel filtration was applied to the separation of molybdenum oxide nanomaterials. This step ensured the isolation of plasmonic MoO x nanoparticles suitable for further bioconjugation and target photothermal treatment.

Isolation, Characterization of Bamboo Leaf Flavonoids by Size Exclusion Chromatography and Their Antioxidant Properties

“…To increase the efficiency of isolation, the purification technology of BLF by Sephadex LH-20 was optimized. [15] Moreover, the in vitro antioxidant activity was measured to evaluate the isolated BLF.…”

“…Sephadex was one of the padding of size exclusion chromatography, and it would isolate the samples based on molecular weight. To increase the efficiency of isolation, the purification technology of BLF by Sephadex LH‐20 was optimized [15] . Moreover, the in vitro antioxidant activity was measured to evaluate the isolated BLF.…”

Selective Tumor Hypoxia Targeting Using M75 Antibody Conjugated Photothermally Active MoOx Nanoparticles

“…The starting material in this case is usually a microcrystalline molybdenum oxide powder. However, we have shown previously that MoO x nanoparticles can also be prepared by spontaneous oxidation of MoS 2 nanoflakes in aqueous solution during LPE. , …”

“…However, we have shown previously that MoO x nanoparticles can also be prepared by spontaneous oxidation of MoS 2 nanoflakes in aqueous solution during LPE. 31,32 MoO x nanomaterials were first introduced as PTT agents in 2014 by Song et al, 24 although many studies have previously reported the existence of localized surface plasmon (LSP) resonance in MoO x -based nanomaterials, see, e.g., ref 33. Several studies followed shortly thereafter, drawing attention to its powerful photothermal effect, demonstrated both on in vitro and in vivo biological models.…”

Elucidating the Role of Electron Transfer in the Photoluminescence of MoS2 Quantum Dots Synthesized by fs-Pulse Ablation

“…These observed peaks are centered at 680 and 1018 nm (cf. SI Figure S4), which are reported as absorption peaks caused by surface plasmon resonance in MoO 3– x . − The surface of nanoparticles that are exposed to laser pulses for a longer time can lead to the formation of these oxide states. Increased ablation time promotes the oxidation of MoS 2 QDs’ surface, resulting in the formation of NIR absorbance peaks and a blue colloidal solution.…”