Molybdenum-doped iron oxide nanostructures synthesized via a chemical co-precipitation route for efficient dye degradation and antimicrobial performance: in silico molecular docking studies

Efficient Dye Degradation and Antimicrobial Behavior with Molecular Docking Performance of Silver and Polyvinylpyrrolidone-Doped Zn-Fe Layered Double Hydroxide

Zn-Fe layered double hydroxide (LDH) was synthesized through the low-temperature-based coprecipitation method. Various concentrations of Ag (1, 3, and 5 wt %) with a fixed amount (5 wt %) of polyvinylpyrrolidone (PVP) were doped into LDH nanocomposites. This research aims to improve the bactericidal properties and catalytic activities of doping-dependent nanocomposites. Adding Ag and PVP to LDH enhanced oxygen vacancies, which increased the amount of hydroxide adsorption sites and the number of active sites. The doped LDH was employed to degrade rhodamine-B dye in the presence of a reducing agent (NaBH4), and the obtained results showed maximum dye degradation in a basic medium compared to acidic and neutral. The bactericidal efficacy of doped Zn-Fe (5 wt %) showed a considerably greater inhibition zone of 3.65 mm against Gram-negative (G-ve) or Escherichia coli (E. coli). Furthermore, molecular docking was used to decipher the mystery behind the microbicidal action of Ag-doped PVP/Zn-Fe LDH and to propose an inhibition mechanism of β-ketoacyl-acyl carrier protein synthase IIE. coli (FabH) and deoxyribonucleic acid gyrase E. coli behind in vitro results.

The Promise of Metal-Doped Iron Oxide Nanoparticles as Antimicrobial Agent

Antibiotic resistance (AMR) is one of the pressing global public health concerns and projections indicate a potential 10 million fatalities by the year 2050. The decreasing effectiveness of commercially available antibiotics due to the drug resistance phenomenon has spurred research efforts to develop potent and safe antimicrobial agents. Iron oxide nanoparticles (IONPs), especially when doped with metals, have emerged as a promising avenue for combating microbial infections. Like IONPs, the antimicrobial activities of doped-IONPs are also linked to their surface charge, size, and shape. Doping metals on nanoparticles can alter the size and magnetic properties by reducing the energy band gap and combining electronic charges with spins. Furthermore, smaller metal-doped nanoparticles tend to exhibit enhanced antimicrobial activity due to their higher surface-to-volume ratio, facilitating greater interaction with bacterial cells. Moreover, metal doping can also lead to increased charge density in magnetic nanoparticles and thereby elevate reactive oxygen species (ROS) generation. These ROS play a vital role to disrupt bacterial cell membrane, proteins, or nucleic acids. In this review, we compared the antimicrobial activities of different doped-IONPs, elucidated their mechanism(s), and put forth opinions for improved biocompatibility.

Synthesis of curcuma longa doped cellulose grafted hydrogel for catalysis, bactericidial and insilico molecular docking analysis

Curcumin (diferuloylmethane), the primary curcuminoid in turmeric rhizome, has been acknowledged as a bioactive compound for numerous pharmacological activities. Nonetheless, the hydrophobic nature, rapid metabolism, and physicochemical and biological instability of this phenolic compound correspond to its poor bioavailability. So, recent scientific advances have found many components and strategies for enhancing the bioavailability of curcumin with the inclusion of biotechnology and nanotechnology to address its existing limitations. Therefore, In this study, copolymerized aqua-gel was synthesized by graft polymerization of poly-acrylic acid (P-AA) on cellulose nanocrystals (CNC), after that Curcuma longa (Cur) was incorporated as dopant (5, 10, 15, and 25 mg) in hydrogel (Cur/C-P) as a stabilizing agent for evaluation of bacterial potential and sewage treatment. The antioxidant tendency of 25 mg Cur/C-P was much higher (72.21 %) than other samples and displayed a catalytic activity of up to 93.89 % in acidic conditions and optimized bactericidal inclinations toward gram-positive bacterial strains. Furthermore, ligand binding was conducted against targeted protein enoyl-[acylcarrier-protein] reductase (FabI) enzyme to comprehend the putative mechanism of microbicidal action of CNC-PAA (CP), Cur/C-P, and curcumin. Our outcomes suggest that 25 mg Cur/C-P hydrogels are plausible sources for hybrid, multifunctional biological activity.

Interfacial regulation of BiOI@Bi2S3/MXene heterostructures for enhanced photothermal and photodynamic therapy in antibacterial applications

Developing environmentally friendly, broad-spectrum, and long-lasting antibacterial materials remains challenging. Our ternary BiOI@Bi2S3/MXene composites, which exhibit both photothermal therapy (PTT) and photodynamic therapy (PDT) antibacterial properties, were synthesized through in-situ vulcanization of hollow flower-shaped BiOI on the surface of two-dimensional Ti3C2 MXene. The unique hollow flower-shaped BiOI structure with a high exposure of the (001) crystal plane amplifies light reflection and scattering, offering more active sites to improve light utilization. Under 808 nm irradiation, these composites achieved a photothermal conversion efficiency of 57.8 %, boosting the PTT antibacterial effect. The heterojunction between Bi2S3 and BiOI creates a built-in electric field at the interface, promoting hole and electron transfer. Significantly, the close-contact heterogeneous interface enhances charge transfer and suppresses electron-hole recombination, thereby boosting PDT bacteriostatic performance. EPR experiments confirmed that ∙O2- and •OH radicals play major roles in photocatalytic bacteriostatic reactions. The combined antibacterial action of PTT and PDT led to efficiencies of 99.7 % and 99.8 % against P. aeruginosa and S. aureus, respectively, under 808 nm laser irradiation. This innovative strategy and thoughtful design open new avenues for heterojunction materials in PTT and PDT sterilization. STATEMENT OF SIGNIFICANCE: Photodynamic and photothermal therapy is a promising antibacterial treatment, but its efficiency still limits its application. To overcome this limitation, we prepared three-dimensional heterogeneous BiOI@Bi2S3/MXene nanocomposites through in-situ vulcanization of hollow flower-shaped BiOI with a high exposure of the (001) crystal plane onto the surface of two-dimensional MXene material. The resulting ternary material forms a close-contact heterogeneous interface, which improves charge transfer channels, reduces electron-hole pair recombination, and amplifies photodynamic bacteriostatic performance. These nanocomposites exhibit photothermal conversion efficiency of 57.8 %, enhancing their photothermal bactericidal effects. They demonstrated antibacterial efficiencies of 99.7 % against P. aeruginosa and 99.8 % against S. aureus. Therefore, this study provides a promising method for the synthesis of environmentally friendly and efficient antibacterial materials.

Antimicrobial potential and rhodamine B dye degradation using graphitic carbon nitride and polyvinylpyrrolidone doped bismuth tungstate supported with in silico molecular docking studies

The environmental-friendly hydrothermal method has been carried out to synthesize Bi2WO6 and g-C3N4/PVP doped Bi2WO6 nanorods (NRs) by incorporating different concentrations of graphitic carbon nitride (g-C3N4) as well as a specified quantity of polyvinylpyrrolidone (PVP). Bi2WO6 doped with g-C3N4 provides structural and chemical stability, reduces charge carriers, degrades dyes, and, owing to lower bandgap energy, is effective for antibacterial, catalytic activity, and molecular docking analysis. The purpose of this research is the treatment of polluted water and to investigate the bactericidal behavior of a ternary system. The catalytic degradation was performed to remove the harmful rhodamine B (RhB) dye using NaBH4 in conjunction with prepared NRs. The specimen compound demonstrated antibacterial activity against Escherichia coli (E. coli) at both high and low concentrations. Higher doped specimens of g-C3N4/PVP-doped Bi2WO6 exhibited a significant improvement in efficient bactericidal potential against E. coli (4.55 mm inhibition zone). In silico experiments were carried out on enoyl-[acylcarrier-protein] reductase (FabI) and β-lactamase enzyme for E. coli to assess the potential of Bi2WO6, PVP doped Bi2WO6, and g-C3N4/PVP-doped Bi2WO6 NRs as their inhibitors and to justify their possible mechanism of action.

Catalytic performance and antibacterial behaviour with molecular docking analysis of silver and polyacrylic acid doped graphene quantum dots

In this research, a fixed concentration (3 wt%) of Ag/PAA and PAA/Ag doped graphene quantum dots (GQDs) were synthesized using the co-precipitation technique. A variety of characterization techniques were employed to synthesize samples to investigate their optical, morphological, structural, and compositional analyses, antimicrobial efficacy, and dye degradation potential with molecular docking analysis. GQDs have high solubility, narrow band gaps, and are suitable for electron acceptors and donors but show less adsorption and catalytic behavior. Incorporating polyacrylic acid (PAA) into GQDs increases the catalytic and antibacterial activities due to the carboxylic group (-COOH). Furthermore, introducing silver (Ag) increased the degradation of dye and microbes as it had a high surface-to-volume ratio. In addition, molecular docking studies were used to decipher the mechanism underlying the bactericidal action of silver and polyacrylic acid-doped graphene quantum dots and revealed inhibition of β-lactamase and DNA gyrase.

Catalytic evaluation and in vitro bacterial inactivation of graphitic carbon nitride/carbon sphere doped bismuth oxide quantum dots with evidential in silico analysis

Herein, Bi2O3 quantum dots (QDs) have been synthesized and doped with various concentrations of graphitic carbon nitride (g-C3N4) and a fixed amount of carbon spheres (CS) using a co-precipitation technique. XRD analysis confirmed the presence of monoclinic structure along the space group P21/c and C2/c. Various functional groups and characteristic peaks of (Bi-O) were identified using FTIR spectra. QDs morphology of Bi2O3 showed agglomeration with higher amounts of g-C3N4 by TEM analysis. HR-TEM determined the variation in the d-spacing which increased with increasing dopants. These doping agents were employed to reduce the exciting recombination rate of Bi2O3 QDs by providing more active sites which enhance antibacterial activity. Notably, (6 wt%) g-C3N4/CS-doped Bi2O3 exhibited considerable antimicrobial potential in opposition to E. coli at higher values of concentrations relative to ciprofloxacin. The (3 wt%) g-C3N4/CS-doped Bi2O3 exhibits the highest catalytic potential (97.67%) against RhB in a neutral medium. The compound g-C3N4/CS-Bi2O3 has been suggested as a potential inhibitor of β-lactamaseE. coli and DNA gyraseE. coli based on the findings of a molecular docking study that was in better agreement with in vitro bactericidal activity.

Efficient Dye Degradation and Antibacterial Activity of Carbon Dots/Chitosan-Doped La2O3 Nanorods: In Silico Molecular Docking Analysis

This work demonstrates the degradation of toxic RhB (rhodamine B) dye from polluted water in various pH environments. It assesses the antibacterial action of CDs (carbon dots)/CS (chitosan)-doped La₂O₃ (lanthanum oxide) NRs (nanorods). CS and CDs have been introduced as dopants to modify the characteristics of La₂O₃ to achieve efficient outcomes. The influence of doping on the structural, morphological, optical, and elemental properties of synthesized La₂O₃ NRs was investigated through a number of analytical techniques. The structural analysis of XRD revealed a hexagonal phase. The rod-like structure of pure La₂O₃ and reduction in the size of NRs upon doping were exhibited by TEM micrographs. From UV-vis spectroscopy, increased absorption upon doping and introduction of redshift that led to reduced bandgap energy were observed. The FTIR spectra indicate the presence of functional groups of pure and integrated samples. The catalytic activity of specimens in basic medium toward dye showed excellent results (94.57%). The inhibition zone of diameter 4.15 mm was evaluated by 6 mL of CDs/CS-doped La₂O₃ NRs against Escherichia coli once the surface area increased by dopants. In silico experiments were performed for enoyl-[acyl-carrier-protein] reductase (FabI) and DNA gyrase enzymes to assess the potency of CS-doped La₂O₃ and CDs/CS-doped La₂O₃ as their inhibitors and to justify their possible mechanism of action.

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.