An Electrochemical Strip to Evaluate and to Discriminate Drug Encapsulation in Lipid Nanovectors.

Lipid nanovectors (LNVs) represent potent and versatile tools in the field of drug delivery for a wide range of medical applications including cancer therapy and vaccines. With this Technical Note, we introduce a novel "portable", easy-to-use, and low-cost strategy for double use: (1) it allows one to both quantify the amount of cargo in LNV formulation and (2) classify the nature of formulation with the aim of chemometrics. In particular, an electrochemical strip, based on a screen-printed electrode, was exploited to detect methylene blue (MB) as the model cargo encapsulated in various liposomes (used as model LNV). The experimental setup, including release of the MB content and its electrochemical quantification were optimized through a multivariate design of experiment (DoE), obtaining a satisfactory 88-95% accuracy in comparison to standard methods. In addition, the use of principal component analysis-linear discriminant analysis (PCA-LDA) highlighted the satisfactory differentiation of liposomes. The combination of portable electroanalysis and multivariate analysis is a potent tool for enhancing quality control in the field of pharmaceutical technologies, and also in the field of diagnostics, this approach might be useful for application toward naturally occurring lipid nanoparticles, i.e., exosomes.

Wavelength-Resolved Janus Biosensing Interface for Ratiometric Electrochemical Analysis.

The Janus interface, comprising multiple functional heterointerfaces with contrasting functionalities within a single interface, has recently garnered widespread research interest. Herein, a Janus biosensing interface is obtained via wavelength-resolved laser illumination. Deoxyribonucleic acid bridges the electrochemical probe of methylene blue (MB) and plasmonic gold nanoparticles (AuNPs), achieving a sensitive detection performance. MB shows differential electrochemical signals under front (I532front) and back (I650back) laser illumination at 532 and 650 nm, respectively, owing to the selective wavelength-resolved effect. Thus, the presence of a wavelength-resolved laser enabled the design of a biosensing interface with Janus properties. The change in the distance between MB and AuNPs induced by aflatoxin B1 (AFB1) indicates that a sensitive response of the Janus biosensing interface can be achieved. A ratiometric strategy is introduced to describe the electrochemical signals of the I532front and I650back for improved robustness. The obtained linear range is 0.0005-50 ng mL-1, with a detection limit of 0.175 pg mL-1. Our study demonstrated that the wavelength-resolved Janus interface enables an electrochemical biosensor with excellent sensitivity. This finding provides an efficient approach for improving biosensor performance.

Portable Saliva Sensor Based on Dual Recognition Elements for Detection of Caries Pathogenic Bacteria.

Dental caries is one of the most common diseases affecting more than 2 billion people's health worldwide. In a clinical setting, it is challenging to predict and proactively guard against dental cavities prior to receiving a confirmed diagnosis. Streptococcus mutans (S. mutans) in saliva has been recognized as the main causative bacterial agent that causes dental caries. High sensitivity, good selectivity, and a wide detection range are incredibly important factors to affect S. mutans detection in practical applications. In this study, we present a portable saliva biosensor designed for the early detection of S. mutans with the potential to predict the occurrence of dental cavities. The biosensor was fabricated using a S. mutans-specific DNA aptamer and S. mutans-imprinted polymers. Methylene blue was utilized as a redox probe in the sensor to generate current signals for analysis. When S. mutans enters complementarily S. mutans cavities, it blocks electron transfer between methylene blue and the electrode, resulting in decreases in the reduction current signal. The signal variations are associated with S. mutans concentrations that are useful for quantitative analysis. The linear detection range of S. mutans is 102-109 cfu mL-1, which covers the critical concentration of high caries risk. The biosensor exhibited excellent selectivity toward S. mutans in the presence of other common oral bacteria. The biosensor's wide detection range, excellent selectivity, and low limit of detection (2.6 cfu mL-1) are attributed to the synergistic effect of aptamer and S. mutans-imprinted polymers. The sensor demonstrates the potential to prevent dental caries.

A rationally designed nuclei-targeting FAPI 04-based molecular probe with enhanced tumor uptake for PET/CT and fluorescence imaging.

PURPOSE: Fibroblast activation protein inhibitor (FAPI) -based probes have been widely studied in the diagnosis of various malignant tumors with positron emission tomography/computed tomography (PET/CT). However, current imaging studies of FAPI-based probes face challenges in rapid clearance rate and potential false-negative results. Furthermore, FAPI has been rarely explored in optical imaging. Considering this, further modifications are imperative to improve the properties of FAPI-based probes to address existing limitations and broaden their application scenarios. In this study, we rationally introduced methylene blue (MB) to FAPIs, thereby imparting nuclei-targeting and fluorescence imaging capabilities to the probes. Furthermore, we evaluated the added value of FAPI-based fluorescence imaging to traditional PET/CT, exploring the potential application of FAPI-based probes in intraoperative fluorescence imaging. METHODS: A new FAPI-based probe, namely NOTA-FAPI-MB, was designed for both PET/CT and fluorescence imaging by conjugation of MB. The targeting efficacy of the probe was evaluated on fibroblast activation protein (FAP)-transfected cell line and human primary cancer-associated fibroblasts (CAFs). Subsequently, PET/CT and fluorescence imaging were conducted on tumor-bearing mice. The tumor detection and boundary delineation were assessed by fluorescence imaging of tissues from hepatocellular carcinoma (HCC) patients. RESULTS: NOTA-FAPI-MB demonstrated exceptional targeting ability towards FAP-transfected cells and CAFs in comparison to NOTA-FAPI. This benefit arises from the cationic methylene blue (MB) affinity for anionic nucleic acids. PET/CT imaging of tumor-bearing mice revealed significantly higher tumor uptake of [18F]F-NOTA-FAPI-MB (standard uptake value of 2.20 ± 0.31) compared to [18F]F-FDG (standard uptake value of 1.66 ± 0.14). In vivo fluorescence imaging indicated prolonged retention at the tumor site, with retention lasting up to 24 h. In addition, the fluorescent probes enabled more precise lesion detection and tumor margin delineation than clinically used indocyanine green (ICG), achieving a 100.0% (6/6) tumor-positive rate for NOTA-FAPI-MB while 33.3% (2/6) for ICG. These findings highlighted the potential of NOTA-FAPI-MB in guiding intraoperative surgical procedures. CONCLUSIONS: The NOTA-FAPI-MB was successfully synthesized, in which FAPI and MB simultaneously contributed to the targeting effect. Notably, the nuclear delivery mechanism of the probes improved intracellular retention time and targeting efficacy, broadening the imaging time window for fluorescence imaging. In vivo PET/CT demonstrated favorable performance of NOTA-FAPI-MB compared to [18F]F-FDG. This study highlights the significance of fluorescence imaging as an adjunct technique to PET/CT. Furthermore, the encouraging results obtained from the imaging of human HCC tissues hold promise for the potential application of NOTA-FAPI-MB in intraoperative fluorescent surgery guidance within clinical settings.

A Magnesium Binding Site And The Anomeric Effect Regulate The Abiotic Redox Chemistry Of Nicotinamide Nucleotides.

Nicotinamide adenine dinucleotide (NAD+) is a redox active molecule that is universally found in biology. Despite the importance and simplicity of this molecule, few reports exist that investigate which molecular features are important for the activity of this ribodinucleotide. By exploiting the nonenzymatic reduction and oxidation of NAD+ by pyruvate and methylene blue, respectively, we were able to identify key molecular features necessary for the intrinsic activity of NAD+ through kinetic analysis. Such features may explain how NAD+ could have been selected early during the emergence of life. Simpler molecules, such as nicotinamide, that lack an anomeric carbon are incapable of accepting electrons from pyruvate. The phosphate moiety inhibits activity in the absence of metal ions but facilitates activity at physiological pH and model prebiotic conditions by recruiting catalytic Mg2+. Reduction proceeds through consecutive single electron transfer events. Of the derivatives tested, including nicotinamide mononucleotide, nicotinamide riboside, 3-(aminocarbonyl)-1-(2,3-dihydroxypropyl)pyridinium, 1-methylnicotinamide, and nicotinamide, only NAD+ and nicotinamide mononucleotide would be capable of efficiently accepting and donating electrons within a nonenzymatic electron transport chain. The data are consistent with early metabolic chemistry exploiting NAD+ or nicotinamide mononucleotide and not simpler molecules.

Adsorption of Organic Pollutants on Carbonaceous Adsorbents Prepared by Direct Activation of Sweet Cherry Stones.

The main objective of this study was to assess the usefulness of the sweet cherry stones for the production of carbonaceous adsorbents by means of direct physical activation method, using conventional and microwave variant of heating. The adsorbents were characterized in terms of textural parameters, acidic-basic character of the surface, electrokinetic properties and their suitability for drinking water purification. Adsorption tests were carried out against three organic compounds - Triton X-100 (surfactant), bovine serum albumin (protein) and methylene blue (synthetic dye). Depending on the variant of heating applied during activation procedure, the obtained activated biochars differed significantly in terms of the elemental composition, acidic-basic properties as well as degree of specific surface development and the type of porous structure generated. Adsorption tests have showed that the efficiency of organic pollutants removal from aqueous solutions depends significantly not only on the type of the adsorbent and adsorbate applied, but also on the temperature and pH of the system. The sample prepared by microwave-assisted direct activation proved to be very effective in terms of all tested organic pollutants adsorption. The maximum sorption capacity toward Triton X-100, bovine serum albumin and methylene blue reached the level of 86.5, 23.4 and 81.1 mg/g, respectively.

Unveiling the Nature of lignin's Interaction with Molecules: A Mechanistic Understanding of Adsorption of Methylene Blue Dye.

The valorization of lignin into advanced materials for water and soil remediation is experiencing a surge in demand. However, it is imperative that material research and manufacturing be sustainable to prevent exacerbating environmental issues. Meeting these requirements necessitates a deeper understanding of the role of lignin's functional groups in attracting targeted species. This research delves into the interaction mechanisms between lignin and organic molecules, using the adsorption of the cationic dye Methylene Blue (MB+) as a case study. Herein, we aim to quantitatively estimate the contribution of different interaction types to the overall adsorption process. While carbonyl groups were found to have no significant role in attraction, carboxylic groups (-COOH) exhibited significantly lower adsorption compared with hydroxyl groups (-OH). Through alternately blocking aliphatic and phenolic -OH groups, we determined that 61% of the adsorption occurred through hydrogen bonding and 38% via electrostatic interactions. Performance studies of modified lignin along with spectroscopic methods (XPS, FTIR) confirmed the negligible role of π-π interactions in adsorption. This study offers fundamental insights into the mechanistic aspects of MB adsorption on lignin, laying the groundwork for potential modifications to enhance the performance of lignin-based adsorbents. The findings underscore the importance of hydroxyl groups and provide a roadmap for future studies examining the influence of steric factors and interactions with other organic molecules.

Phosphorylating Tannin in Urea System: A Simple Approach for Enhanced Methylene Blue Removal from Aqueous Media.

Tannin, after lignin, is one of the most abundant sources of natural aromatic biomolecules. It has been used and chemically modified during the past few decades to create novel biobased materials. This work intended to functionalize for the first time quebracho Tannin (T) through a simple phosphorylation process in a urea system. The phosphorylation of tannin was studied by Fourier transform infrared spectroscopy (FTIR), NMR, inductively coupled plasma optical emission spectroscopy (ICP-OES), and X-ray fluorescence spectrometry (XRF), while further characterization was performed by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) and thermogravimetric analysis (TGA) to investigate the morphology, composition, structure, and thermal degradation of the phosphorylated material. Results indicated the occurrence of phosphorylation, suggesting the insertion of phosphate-containing groups into the tannin structure, revealing a high content of phosphate for modified tannin (PT). This elevated phosphorus content serves as evidence for the successful incorporation of phosphate groups through the functionalization process. The corresponding PT and T were employed as adsorbents for methylene blue (MB) removal from aqueous solutions. The results revealed that the Langmuir isotherm model effectively represents the adsorption isotherms. Additionally, the pseudo-second-order model indicates that chemisorption predominantly controls the adsorption mechanism. This finding also supports the fact that the introduced phosphate groups via the phosphorylation process significantly contributed to the improved adsorption capacity. Under neutral pH conditions and at room temperature, the material achieved an impressive adsorption capacity of 339.26 mg·g-1 in about 2 h.

DNA nanotechnology for nucleic acid analysis: sensing of nucleic acids with DNA junction-probes.

DNA nanotechnology deals with the design of non-naturally occurring DNA nanostructures that can be used in biotechnology, medicine, and diagnostics. In this study, we introduced a nucleic acid five-way junction (5WJ) structure for direct electrochemical analysis of full-length biological RNAs. To the best of our knowledge, this is the first report on the interrogation of such long nucleic acid sequences by hybridization probes attached to a solid support. A hairpin-shaped electrode-bound oligonucleotide hybridizes with three adaptor strands, one of which is labeled with methylene blue (MB). The four strands are combined into a 5WJ structure only in the presence of specific DNA or RNA analytes. Upon interrogation of a full-size 16S rRNA in the total RNA sample, the electrode-bound MB-labeled 5WJ association produces a higher signal-to-noise ratio than electrochemical nucleic acid biosensors of alternative design. This advantage was attributed to the favorable geometry on the 5WJ nanostructure formed on the electrode's surface. The 5WJ biosensor is a cost-efficient alternative to the traditional electrochemical biosensors for the analysis of nucleic acids due to the universal nature of both the electrode-bound and MB-labeled DNA components.

Enhancing sensitivity towards electrochemical miRNA detection using an affordable paper-based strategy.

In the era of liquid biopsy, microRNAs emerge as promising candidates for the early diagnosis and prognosis of cancer, offering valuable insights into the disease's development. Among all the existing analytical approaches, even if traditional approaches such as the nucleic acid amplification ones have the advantages to be highly sensitive, they cannot be used at the point-of-care, while sensors might be poorly sensitive despite their portability. In order to improve the analytical performance of existing electroanalytical systems, we demonstrate how a simple chromatographic paper-based disk might be useful to rationally improve the sensitivity, depending on the number of preconcentration cycles. A paper-based electrochemical platform for miRNA detection has been developed by modifying a paper-based electrode with a methylene blue (MB)-modified single-stranded sequence (ssDNA) complementary to the chosen miRNA, namely miR-224 that is associated with lung cancer. A detection limit of ca. 0.6 nM has been obtained in spiked human serum samples. To further enhance the sensitivity, an external chromatographic wax-patterned paper-based disk has been adopted to preconcentrate the sample, and this has been demonstrated both in standard and in serum solutions. For each solution, three miR-224 levels have been preconcentrated, obtaining a satisfactory lowering detection limit of ca. 50 pM using a simple and sustainable procedure. This approach opens wide possibilities in the field of analytical and bioanalytical chemistry, being useful not only for electrochemistry but also for other architectures of detection and transduction.

Modulating temperature for Cu2ZnSnS4 (CZTS) synthesis via hot injection method and studying the photocatalytic efficiencies for the degradation of rhodamine 6G and methylene blue pollutants.

Cu2ZnSnS4 (CZTS) was synthesized following hot injection method and the process was optimized by varying temperature conditions. Four samples at different temperatures viz., 200, 250, 300 and 350 °C were prepared and analyzed using different characterization techniques. Based on the correlation between XRD, Raman and XPS, we conclude that the formation of ZnS and SnS2 occurs at 350 °C but at 200 °C there is no breakdown of the complex as per XRD. According to Raman and XPS analysis, as the temperature rises, the bonds between the metals become weaker, which is visibly seen in Raman and XPS due to the minor peaks of copper sulfide. Scanning electron microscopic analysis confirmed nanometric particles which increase in size with temperature. The photocatalytic evaluation showed that CZTS synthesized at 200 °C performed efficiently in the removal of the two colorants, methylene blue and Rhodamine 6G, achieving 92.80% and 90.65%, respectively. The photocatalytic degradation efficiencies decreased at higher temperatures due to bigger sized CZTS particles as confirmed by SEM results. Computational simulations confirm that CZTS has a highly negative energy -25,764 Ry, confirming its structural stability and higher covalent than ionic character.

Bimetal Cu/Ni-BTC@SiO2 metal-organic framework as high performance photocatalyst for degradation of azo dyes under visible light irradiation.

There has been significant attention on the efficient degradation of pollutants in wastewater using metal-organic frameworks (MOFs) photocatalytic methods over the past decade. Herein, we examined the elimination of two different types of water-contaminating dyes, specifically cationic dye methylene blue (MB) and anionic dye methyl orange (MO), through the application of bimetal Cu/Ni-BTC@SiO2 MOF as high performance photocatalyst. The bimetal Cu/Ni-BTC@SiO2 photocatalyst was synthesized and characterized by XRD, FTIR, SEM, TEM, TGA, BET, DRS, and VSM techniques. The examination of the impact of different operational factors on the elimination of pollutants involved a comprehensive analysis of variables including the photocatalyst type, initial pollutant concentration, quantity of photocatalyst, and pH levels. The highest removal efficiency for MO and MB dyes by the photocatalyst was found to be 98 and 71%, respectively, within 60 min. In the fifth reaction stage, degradation efficiency for MO and MB was 76 and 56% respectively. Kinetic investigations demonstrated that, in the context of the uptake of MB and MO dyes, the interparticle diffusion, and pseudo-second-order models emerged as possessing the most robust correlation coefficients with the experimental data, registering values of 0.988 and 0.961, respectively. The examination of isotherms reveals that the isotherm models proposed by BET, and Anderson (V) demonstrate the highest level of conformity with the empirical data for the decomposition of MB and MO dyes, correspondingly. The TOC levels decreased significantly from 51 to 14 and 47 to 3 mg/L for MB and MO dyes, indicating the effective mineralization process using Cu/Ni-BTC@SiO2.

Novel cow dung-doped sludge biochar as an efficient ozone catalyst: Synergy between graphitic structure and defects induces free radical pathways.

A composite material, cow dung-doped sludge biochar (Zn@SBC-CD), was synthesized by one-step pyrolysis using ZnCl2 as an activating agent and applied to a catalytic ozonation process (COP) for methylene blue (MB) removal. SEM, XRD, FTIR, XPS and BET analyses were performed to characterize the biochar (BC) catalysts. Zn@SBC-CD had high graphitization degree, abundant active sites and uniform distribution of Zn on its surface. Complete removal of MB was achieved within 10 min, with a removal rate much higher than that of ozone alone (32.4%), implying the excellent ozone activation performance of Zn@SBC-CD. The influence of experimental parameters on MB removal efficiency was examined. Under the optimum conditions in terms of ozone dose 0.04 mg/mL, catalyst dose 400 mg/L and pH 6.0, COD was completely removed after 20 min. Electron paramagnetic resonance (EPR) analysis revealed radical and non-radical pathways were involved in MB degradation. The Zn@SBC-CD/O3 system generated superoxide anion radicals (•O2-), which were the main active species for MB removal, through adsorption, transformation, and transfer, Furthermore, Zn@SBC-CD exhibited good reusability and stability in cycling experiments. This study provides a novel approach for the utilization of cow dung and sludge in synthesis of functional biocatalysts and application in organic wastewater treatment.

Analysis of Ag-DP25/PET plasmonic nano-composites as a visible-light photocatalyst for wastewater treatment: Experimental/theoretical studies, and the DFT-MB degradation mechanism.

The development of polymeric-composites Agx%DP25-PET (x = 0,1,2,3) may significantly boost the potential application of Agx%DP25 (x = 0,1,2,3) photocatalytic powders. Producing large-scale nano-composites with hybrid-surfaces, that are also flexible materials and easy to employ in a variety of environments. A set of photocatalytic nan-composites embedded with the polymeric binder poly (acrylonitrile-co-butadiene)-dicarboxy terminated (C7H9N) were performed and evaluated for wastewater treatment applications. The results reveal that the flexible polymeric composites (Agx%DP25-PET, x = 0,1,2,3) have photocatalytic activity in aqua media to degrade methylene blue (MB) under visible-light. The addition of C7H9N to immobilize photocatalytic powders on the PET surface reduces photo-generated electron-hole recombination. The materials were characterized by HR-TEM, SEM/EDX, XRD, FT-IR, UV-Vis DRS and PL. The Agx%DP25-PET (x = 0,1,2,3) photocatalytic reactions exhibited productive discoloration/degradation rates, in both aerobic (AE) and anaerobic (AN) environments. The superior photodegradation of Ag2%DP25-PET was attributed to a combination of two effects: LSPR (localized surface plasmon resonance) and Ag-TiO2/environment affinities. The findings of molecular dynamics (MD) simulation and Fukui Function (FF) based on density functional theory (DFT) provide significant insight into the photocatalytic requirements for MB discoloration/degradation. The experimental/theoretical analysis aimed to offer an in-depth understanding of medium/surface interactions on decorated TiO2 materials, as well as how these interactions affect overall degradation behavior.

Development of a sustainability-oriented university laboratory: Insight into adsorption kinetics models for the removal of pollutants from aqueous solution.

The aim of the present research is to show the development of a sustainability-oriented lab that teaches adsorption concepts in a virtual environment based on the premise "learning-through-play". Kinetic results in the virtual environment are contrasted to those obtained experimentally when diverse adsorbents prepared from Agave Bagasse (Raw Fibers, Hydrothermal Fibers, and Activated Fibers) were synthesized. Comparison between virtual and real-life experiments involving removal of methylene blue in solution showed that a pseudo-first-order model could describe adsorption kinetics satisfactorily. The study is complemented with a characterization of the adsorbents through SEM, nitrogen adsorption isotherms, FTIR and Raman. In addition, the environmental impact of the synthesis of adsorbents was evaluated through well-known methodologies (GAPI, NEMI, and Eco-Scale), which agree that raw fibers are the most eco-friendly material. This research provides an exciting opportunity to advance our knowledge on developing new technologies for teaching in engineering and to compliment real-life practices that consider environmental impacts with virtual experiments.

Integrating DFT and machine learning for the design and optimization of sodium alginate-based hydrogel adsorbents: Efficient removal of pollutants from wastewater.

This study presents a novel approach to design and optimize a sodium alginate-based hydrogel (SAH) for efficient adsorption of the model water pollutant methylene blue (MB) dye. Utilizing density functional theory (DFT) calculations, sodium alginate-g-poly (acrylamide-co-itaconic acid) was identified with the lowest adsorption energy (Eads) for MB dye among 14 different clusters. SAHs were prepared using selected monomers and sodium alginate combinations through graft co-polymerization, and swelling studies were conducted to optimize grafting conditions. Advanced characterization techniques, including FTIR, XRD, XPS, SEM, EDS, and TGA, were employed, and the process was optimized using statistical and machine learning tools. Screening tests demonstrated that Eads serves as an effective predicting indicator for adsorption capacity (qe) and MB removal efficiency (RRMB,%), with reasonable agreement between Eads and both responses under given conditions. Process modeling and optimization revealed that 5 mg of selected SAH achieves a maximum qe of 3244 mg g-1 at 84.4% RRMB under pH 8.05, 98.8 min, and MB concentration of 383.3 mg L-1, as identified by the desirability function approach. Moreover, SAH effectively eliminated various contaminants from aqueous solutions, including sulfasalazine (SFZ) and dibenzothiophene (DBT). MB adsorption onto selected SAH was exothermic, spontaneous, and followed the pseudo-first-order and Langmuir-Freundlich isotherm models. The remarkable ability of SAH to adsorb MB is attributed to its well-designed structure predicted through DFT and optimal operational conditions achieved by AI-based parametric optimization. By integrating DFT-based computations and machine-learning tools, this study contributes to the efficient design of adsorbent materials and optimization of adsorption processes, also showcasing the potential of SAH as an efficient adsorbent for the abatement of aqueous pollution.

Physicochemical and photocatalytic properties of Ag2CrO4/Fe2O3/CeO2 ternary nanocomposite.

The study presents Ag2CrO4/Fe2O3/CeO2 ternary nanocomposite, based on Fe2O3/CeO2 binary composites, which demonstrated excellent photocatalytic performance in the photodegradation of methylene blue under solar irradiation. The Ag2CrO4/Fe2O3/CeO2 nanocomposites was orthorhombic, ilmenite, and cubic-fluorite phases of Ag2CrO4, Fe2O3, and CeO2, respectively, according to the XRD examination. A strong bond between Ag2CrO4, Fe2O3, and CeO2 within the nanocomposite was demonstrated by the SEM and TEM investigations. Moreover, it was discovered that the coupling of Ag2CrO4 and Fe2O3 caused a red shift and moved CeO2 absorption edge from the UV to the visible spectrum. The reason behind this is that the band gap of CeO2 reduced 2.85 to 2.69 eV and the absorbance band intensity increased in visible region. Utilizing visible light, Ag2CrO4/Fe2O3/CeO2 ternary nanocomposites exhibit enhanced photocatalytic properties (98.90%) for the degradation of methylene blue (MB) within 100 min. The long-term reliability and recyclability of the photocatalyst were explored through 3 successive cycles. An active radical quenching test was conducted to elucidate the involvement of O2 - and OH which are the primary reactive species in the photocatalytic breakdown of MB. Ag2CrO4/Fe2O3/CeO2 ternary nanocomposites displayed notable improvements in photodegradation activity, making them well suited for the effective removal of hazardous dyes present in textile effluents.

Green synthesis of tellurium-doped SnO2 nanoparticles with sulfurized g-C3 N4 : Insights into methylene blue photodegradation and antibacterial capability.

The construction of SnO2 nanoparticles (NPs), specifically Te-doped SnO2 NPs, using a simple and economical co-precipitation technique has been thoroughly described in this work. NH3 served as the reducing agent in this procedure, whilst polyethylene glycol served as the capping agent. The primary goals of our work were to investigate the physicochemical properties of the synthesized SnO2 NPs and assess their potential use as antibacterial agents and photocatalysts. Scanning electron microscopy-energy dispersive X-ray, ultraviolet light, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and other analytical techniques were used to thoroughly analyze the NPs. Based on the full width at half maximum of the most noticeable peaks in the XRD spectrum, the Debye-Scherrer equation was used to calculate the crystallite sizes, which indicated the presence of a single tetragonal SnO2 phase. Particularly noteworthy was the exceptional photocatalytic activity of graphene-assisted Te-doped SnO2 NPs, achieving an impressive decomposition efficiency of up to 98% in the photo-oxidation of methylene blue. Furthermore, our investigation delved into the antibacterial attributes of the synthesized SnO2 NPs against Escherichia coli and Staphylococcus aureus, demonstrating inhibitory effects on both bacteria strains. This suggests potential applications for these NPs in various environmental and medical contexts.

Harnessing solar power for enhanced photocatalytic degradation of coloured pollutants using novel Mg-doped-ZnFe2O4/S@g-C3N4 heterojunction: A facile hydrothermal synthesis approach.

The ability of heterogeneous photocatalysis to effectively remove organic pollutants from wastewater has shown great promise as a tool for environmental remediation. Pure zinc ferrites (ZnFe2O4) and magnesium-doped zinc ferrites (Mg@ZnFe2O4) with variable percentages of Mg (0.5, 1, 3, 5, 7, and 9 mol%) were synthesized via hydrothermal route and their photocatalytic activity was checked against methylene blue (MB) taken as a model dye. FTIR, XPS, BET, PL, XRD, TEM, and UV-Vis spectroscopy were used for the identification and morphological characterization of the prepared nanoparticles (NPs) and nanocomposites (NCs). The 7% Mg@ZnFe2O4 NPs demonstrated excellent degradation against MB under sunlight. The 7% Mg@ZnFe2O4 NPs were integrated with diverse contents (10, 50, 30, and 70 wt.%) of S@g-C3N4 to develop NCs with better activity. When the NCs were tested to degrade MB dye, it was revealed that the 7%Mg@ZnFe2O4/S@g-C3N4 NCs were more effective at utilizing solar energy than the other NPs and NCs. The synergistic effect of the interface formed between Mg@ZnFe2O4 and S@g-C3N4 was primarily responsible for the boosted photocatalytic capability of the NCs. The fabricated NCs may function as an effective new photocatalyst to remove organic dyes from wastewater.

Poly-vinyl-pyrrolidone capped luminescent zinc oxide nanocomposites as excellent tools for germicidal and photo-catalytic performances.

Alternate antibiotics developed through the involvement of nanomaterials are gaining interest due to their economical and lower toxicity concerns. A newly developed biopolymer-based polyvinylpyrrolidone/zinc oxide (PVP/ZnO) nanocomposite (NCs) was efficiently synthesized by an environment-friendly approach, utilizing onion and garlic peel extract as a bio-surfactant, zinc acetate as the source, PVP as the stabilizing agent, and sodium hydroxide as the precipitant. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) investigations verified the crystalline properties of ZnO, PVP, and PVP/ZnO-based NCs. The structure of the biopolymer-linked ZnO particles interpolated inside the PVP array was seen to have a layered and flaky structure, as validated by field emission scanning electron microscopy (FE-SEM) analysis, which revealed its occurrence in the nanometer range. The XRD examination verified that the surface topographical image of PVP/ZnO NCs had an average thickness of 21 nm. The PVP/ZnO nanocrystals demonstrated exceptional photocatalytic efficacy, with a breakdown rate of 88% and almost 92% for the methylene blue dye. Therefore, the PVP/ZnO matrix exhibits superior antibacterial activity compared to other extracts, resulting in greater microbial suppression. The results above indicate that the ZnO-intercalated PVP array has a stronger reinforcing effect than other components. Hence, PVP/ZnO nanocrystals exhibit enormous potential as a favorable substance for environmental and biomedical intentions.