MoS2/cellulose-doped ZnO nanorods for catalytic, antibacterial and molecular docking studies

Recent advances in cellulose nanocrystals-based antimicrobial agents

Over the past five years, there has been growing interest in the design of modified cellulose nanocrystals (CNCs) as nanoscale antimicrobial agents in potential end-user applications such as food preservation/packaging, additive manufacturing, biomedical and water purification. The interest of applying CNCs-based antimicrobial agents arise due to their abilities to be derived from renewable bioresources and their excellent physicochemical properties including rod-like morphologies, large specific surface area, low toxicity, biocompatibility, biodegradability and sustainability. The presence of ample surface hydroxyl groups further allows easy chemical surface modifications for the design of advanced functional CNCs-based antimicrobial materials. Furthermore, CNCs are used to support antimicrobial agents that are subjected to instability issues. The current review summarizes recent progress in CNC-inorganic hybrid-based materials (Ag and Zn nanoparticles, other metal/metal oxide) and CNC-organic hybrid-based materials (polymers, chitosan, simple organic molecules). It focuses on their design, syntheses and applications with a brief discussion on their probable modes of antimicrobial action whereby the roles of CNCs and/or the antimicrobial agents are highlighted.

Recent advances in the hybridization of cellulose and semiconductors: Design, fabrication and emerging multidimensional applications: A review

Cellulose is a plentiful, biodegradable, renewable, and natural polymer in the world that can be widely utilized in the production of polymer nanocomposites. Cellulose is developed in nanomaterials owing to its remarkable inherent features of low density, non-toxicity, and affordability, as well as the amazing sample characteristics of strength and thermal stability. Recently, there has been a lot of interest in organic-inorganic composites because of their adaptable qualities. Cellulose and semiconductors have exciting properties, and new combinations of both materials may result in efficient functional hybrid composites with distinct properties. Lately, a huge study was reported on cellulose and semiconductor-based nanocomposites. In this review, we summarize the present research development in the preparation methods, structure, features, and possible applications of multifunctional cellulose and semiconductor-based nanocomposites. The cellulose/semiconductor based nanocomposites have massive potential applications in the areas of photodegradation of organic dyes, hydrogen production, metal removal, biomedical, and sensor applications. It is also assumed that this article will promote additional investigation and will establish innovative capabilities to enhance novel cellulose and semiconductor based nanocomposites with new and exciting applications.

Toward Efficient Bactericidal and Dye Degradation Performance of Strontium- and Starch-Doped Fe2O3 Nanostructures: In Silico Molecular Docking Studies

In this study, various concentrations of strontium (Sr) into a fixed amount of starch (St) and Fe₂O₃ nanostructures (NSs) were synthesized with the co-precipitation approach to evaluate the antibacterial and photocatalytic properties of the concerned NSs. The study aimed to synthesize nanorods of Fe₂O₃ with co-precipitation to enhance the bactericidal behavior with dopant-dependent Fe₂O₃. Advanced techniques were utilized to investigate the structural characteristics, morphological properties, optical absorption and emission, and elemental composition properties of synthesized samples. Measurements via X-ray diffraction confirmed the rhombohedral structure for Fe₂O₃. Fourier-transform infrared analysis explored the vibrational and rotational modes of the O-H functional group and the C=C and Fe-O functional groups. The energy band gap of the synthesized samples was observed in the range of 2.78-3.15 eV, which indicates that the blue shift in the absorption spectra of Fe₂O₃ and Sr/St-Fe₂O₃ was identified with UV-vis spectroscopy. The emission spectra were obtained through photoluminescence spectroscopy, and the elements in the materials were determined using energy-dispersive X-ray spectroscopy analysis. High-resolution transmission electron microscopy micrographs showed NSs that exhibit nanorods (NRs), and upon doping, agglomeration of NRs and nanoparticles was observed. Efficient degradations of methylene blue increased the photocatalytic activity in the implantation of Sr/St on Fe₂O₃ NRs. The antibacterial potential for Escherichia coli and Staphylococcus aureus was measured against ciprofloxacin. E. coli bacteria exhibit inhibition zones of 3.55 and 4.60 mm at low and high doses, respectively. S. aureus shows the measurement of inhibition zones for low and high doses of prepared samples at 0.47 and 2.40 mm, respectively. The prepared nanocatalyst showed remarkable antibacterial action against E. coli bacteria rather than S. aureus at high and low doses compared to ciprofloxacin. The best-docked conformation of the dihydrofolate reductase enzyme against E. coli for Sr/St-Fe₂O₃ showed H-bonding interactions with Ile-94, Tyr-100, Tyr-111, Trp-30, ASP-27, Thr-113, and Ala-6.

Experimental and theoretical study of catalytic dye degradation and bactericidal potential of multiple phase Bi and MoS2 doped SnO2 quantum dots†

In the present study, different concentrations (1 and 3%) of Bi were incorporated into a fixed amount of molybdenum disulfide (MoS₂) and SnO₂ quantum dots (QDs) by co-precipitation technique. This research aimed to increase the efficacy of dye degradation and bactericidal behavior of SnO₂. The high recombination rate of SnO₂ can be decreased upon doping with two-dimensional materials (MoS₂ nanosheets) and Bi metal. These binary dopants-based SnO₂ showed a significant role in methylene blue (MB) dye degradation in various pH media and antimicrobial potential as more active sites are provided by nanostructured MoS₂ and Bi³⁺ is responsible for producing a variety of different oxygen vacancies within SnO₂. The prepared QDs were described via morphology, optical characteristics, elemental composition, functional group, phase formation, crystallinity, and d-spacing. In contrast, antimicrobial activity was checked at high and low dosages against Escherichia coli (E. coli) and the inhibition zone was calculated utilizing a Vernier caliper. Furthermore, prepared samples have expressed substantial antimicrobial effects against E. coli. To further explore the interactions between the MB and Bi/MoS₂–SnO₂ composite, we modeled and calculated the MB adsorption using density functional theory and the Heyd–Scuseria–Ernzerhof hybrid (HSE06) approach. There is a relatively strong interaction between the MB molecule and Bi/MoS₂–SnO₂ composite.

In the present study, different concentrations (1 and 3%) of Bi were incorporated into a fixed amount of molybdenum disulfide and SnO₂ quantum dots by co-precipitation technique. This research aimed to increase the efficacy of dye degradation and bactericidal behavior of SnO₂.

Structural, morphological, and optical properties of carbon nanoparticles unsheathed from date palm fronds

Several studies have reported the synthesis of carbon nanoparticles (CNPs) by various methods. In this study, an easy one-step process to unsheathe CNPs from date palm fronds through a top-down ball milling method has been reported. The CNPs were characterized using various spectroscopic and microscopic methods to determine their structural and morphological features, optical properties, crystallinity, physicochemical properties, and particle stability. Transmission electron microscopy (TEM) revealed that the obtained CNPs' size ranged from 4 to 22 nm in a crystalline form. Scanning electron microscopy (SEM) confirmed their spherical shape, while the maximum photoluminescence (PL) intensity was recorded at 464 nm when excited at 375 nm. The unsheathed CNPs produced a good quantum yield (QY) of 3.24%. Furthermore, the CNPs exhibited high Raman ratios of I D/I G and I 2D/I G with values of 0.59 and 0.04, respectively, verifying their multilayer crystalline graphitic nature. These Raman ratios also agree with the X-ray diffractometry (XRD) results. The CNPs' sp2 and sp3 carbon bonds were confirmed by X-ray photoelectron spectroscopy (XPS), with oxygen on the surface forming carboxyl and carbonyl groups with no other observable impurities. Furthermore, the extracted CNPs showed excellent PL properties for up- and down-conversion. These properties are exemplary for low-cost biomass with potential applications in biomedicine. Therefore, the extracted CNPs reported in this study have potential applications in optical imaging.