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The toxicity of arsenic and mercury is highly dependent on their unique chemical forms, mobility, bioavailability, and biological roles. This places a strong demand on specific metal species analysis rather than total quantification. Graphene oxide (GO) is an excellent adsorbent for the extraction of metal ions; however, the functional moieties on the GO surface are not metal ion-specific. In this work, we chemically introduced thioglycolic acid to improve metal ion selectivity after the dual oxidation of graphite to generate graphene oxide (GO) nanosheets. The prepared adsorbent was characterized by various spectroscopic and microscopic techniques. A solid phase extraction method was developed after careful analysis and optimization of the prepared sorbent. The method shows a fairly good quantification limit of 0.20 µg L−1 for As(III) and Hg(II) ions. From diverse water samples, the proposed sorbent preferentially removes As(III) and Hg(II) ions (tap water and groundwater). The remarkable wettability and analyte accessibility that the surface-bonded thiol functionality of GO sheets offers is an exciting feature. In a lesser amount of time, the GO−SH nanosorbent exhibits good extraction of traces of As(III) and Hg(II). The developed method exhibits good reliability and precision in terms of accuracy and relative standard deviation (RSD 3.8%; N = 5) and has low detection limits (0.04 µg L−1). Real samples that had been spiked to a predefined level were analyzed in order to validate the established procedure.

Metal ion extraction and determination at trace level concentration are challenging due to sample complexity or spectral interferences. Herein, we prepared a through-hole aluminum oxide membrane (AOM) by electrochemical anodization of aluminum substrates. The prepared AOM was characterized by scanning electron microscopy, surface area analysis, porosity measurements, and X-ray photoelectron spectroscopy. The AOM with ordered nanopores was highly porous and possess inherent binding sites for selective arsenite sorption. The AOM was used as a novel sorbent for solid-phase microextraction and preconcentration of arsenite ions in water samples. The AOM’s sub-micrometer thickness allows water molecules to flow freely across the pores. Before instrumental determination, the suggested microextraction approach removes spectral interferents and improves the analyte ion concentration, with a detection limit of 0.02 μg L–1. Analyzing a standard reference material was used to validate the procedure. Student’s t-test value was less than critical Student’s t-value of 4.303 at a 95% confidence level. With coefficients of variation of 3.25%, good precision was achieved.

Optimized structures for Hg(ii) complexation with mercaptoacetic acid.

Heavy metal ions can have a negative impact on human health when they are present in the environment and diet. In order to enhance healthcare globally, simple, dependable, sensitive, rapid, and accurate technologies for their detection must be created. Herein, we report a sol-gel preparation of nickel oxide (NiO) nanoparticles. The prepared NiO nanoparticles are extensively characterized by PXRD, SEM, and EDS approaches. The obtained SEM results showed that NiO has a nanosphere-shaped surface morphology. The surface area of a gold electrode (Au) was fabricated with NiO nanoparticles via the drop-casting method. The fabricated electrode with NiO nanoparticles (NiO/Au) was applied as an arsenic sensor. The NiO/Au exhibits decent sensitivity of 3.10 µA/ppb and a limit of detection of 1.94 ppb. The NiO/Au also shows good sensing performance for arsenic detection, which includes good stability, repeatability, and selectivity. So far, this is the first report which adopted two electrochemical techniques (cyclic voltammetry and linear sweep voltammetry) for the detection of arsenic using NiO/Au.

Recently, the simulation of perovskite solar cells (PSCs) via SCAPS-1D has been widely reported. In this study, we adopted SCAPS-1D as a simulation tool for the numerical simulation of lead-free (Pb-free) PSCs. We used methyl ammonium germanium iodide (MAGeI3) as a light absorber, zinc oxysulphide (ZnOS) as an electron transport layer (ETL), and spiro-OMeTAD as a hole transport layer. Further, the thickness of the ZnOS, MAGeI3, and spiro-OMeTAD layers was optimized. The optimal thicknesses of the ZnOS, MAGeI3, and spiro-OMeTAD layers were found to be 100 nm, 550 nm, and 100 nm, respectively. The optimized MAGeI3-based PSCs exhibited excellent power conversion efficiency (PCE) of 21.62%, fill factor (FF) of 84.05%, and Jsc of 14.51 mA/cm2. A fantastic open circuit voltage of 1.77 V was also obtained using SCAPS-1D. We believe that these theoretically optimized parameters and conditions may help improve the experimental efficiency of MAGeI3-based PSCs in the future.

The discharge of dyes from textile industries led to a broad range of toxicological and environmental effects, posing severe health issues for humans and animals worldwide. These dyes are highly stable and, if not adequately treated, remain in the environment for extended periods. Adsorption, the most efficient and cost-effective method, offers unique advantages for using natural adsorbents, such as marble waste composites, for dye removal. The easy availability of marble waste, its low cost, its eco-friendly nature, its ease of operation, its simplicity of design, its flexibility, and its great affinity for dyes make it a suitable option for dye removal. Golden marble waste nanocomposites are prepared for dye removal. The results from the studies suggested that treated golden marble composite materials exhibit better adsorption efficiency (224.8, 299.5, and 369.2 mg/g) for adsorptive removal of dyes than untreated golden marble composite materials (114.4 mg/g). This research also used isothermic and kinetic models to evaluate the effects of numerous parameters, for example, the initial dye concentration, pH, time, temperature, and adsorbent dose. The highest removal of 369.9 mg/g was achieved during the present study for blue dye at an optimized pH of 7 and a temperature of 30 °C. It was observed that golden marble waste composites gave better R2 (0.99) values for second-order kinetics in the kinetic model. Results obtained from comparing Langmuir, Freundlich, Temkin, Dubinin, and Herkin Jura isotherms showed that the R2 values of the Langmuir isotherm for Foron red (0.97), the Temkin isotherm for Foron blue (0.98), and the Freundlich isotherm for Foron black dye (0.97) fit on adsorption for both treated and untreated composites. Characterization techniques, such as scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), are also discussed for the structural determination of golden marble waste composites.

Hydroquinone is a widely used derivative of phenol which has a negative influence on human beings and the environment. The determination of the accurate amount of hydroquinone is of great importance. Recently, the fabrication of an electrochemical sensing device has received enormous attention. In this study, we reported on the facile synthesis of cerium dioxide (CeO2) nanoparticles (NPs). The CeO2 NPs were synthesized using cerium nitrate hexahydrate as a precursor. For determining the physicochemical properties of synthesized CeO2 NPs, various advanced techniques, viz., powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS), were studied. Further, these synthesized CeO2 NPs were used for the modification of a glassy carbon electrode (CeO2/GCE), which was utilized for the sensing of hydroquinone (HQ). A decent detection limit of 0.9 µM with a sensitivity of 0.41 µA/µM cm2 was exhibited by the modified electrode (CeO2/GCE). The CeO2/GCE also exhibited good stability, selectivity, and repeatability towards the determination of HQ.

Recently, the design and fabrication of lead (Pb)-free perovskite or perovskite-like materials have received great interest for the development of perovskite solar cells (PSCs). Manganese (Mn) is a less toxic element, which may be an alternative to Pb. In this work, we explored the role of NH3(CH2)2NH3MnCl4 perovskite as a light absorber layer via SCAPS-1D. A Pb-free PSC device (FTO/TiO2/NH3(CH2)2NH3MnCl4/spiro-OMeTAD/Au) was simulated via SCAPS-1D software. The simulated Pb-free PSCs (FTO/TiO2/NH3(CH2)2NH3MnCl4/spiro-OMeTAD/Au) showed decent power conversion efficiency (PCE) of 20.19%. Further, the impact of the thickness of absorber (NH3(CH2)2NH3MnCl4), electron transport (TiO2), and hole-transport (spiro-OMeTAD) layers were also investigated. Subsequently, various electron transport layers (ETLs) were also introduced to investigate the role of ETL. In further studies, an NH3(CH2)2NH3MnCl4-based PSC device (FTO/TiO2/NH3(CH2)2NH3MnCl4/spiro-OMeTAD/Au) was also developed (humidity = ~30–40%). The fabricated PSCs displayed an open circuit voltage (Voc) of 510 mV with a PCE of 0.12%.

Hydroquinone is a widely used derivative of phenol which has a negative influence on human beings and the environment. The determination of the accurate amount of hydroquinone is of great importance. Recently, the fabrication of an electrochemical sensing device has received enormous attention. In this study, we reported on the facile synthesis of cerium dioxide (CeO

Serotonin is a very important monoamine neurotransmitter, which takes part in biological and psychological processes. In the present scenario, design and fabrication of a serotonin electrochemical sensor is of great significance. In this study, we have synthesized α-MnO

Lactoferrin is a heme-binding multifunctional glycoprotein known for iron transportation in the blood and also contributes to innate immunity. In this study, the interaction of theaflavin monogallate, a polyphenolic component of black tea, with camel milk lactoferrin was studied using various biophysical and computational techniques. Fluorescence quenching at different temperatures suggests that theaflavin monogallate interacted with lactoferrin by forming a non-fluorescent complex, i.e., static quenching. Theaflavin monogallate shows a significant affinity towards lactoferrin with a binding constant of ∼104–105 M−1 at different temperatures. ANS binding shows that the binding of polyphenol resulted in the burial of hydrophobic domains of lactoferrin. Moreover, thermodynamic parameters (ΔH, ΔS and ΔG) suggested that the interaction between protein and polyphenol was entropically favored and spontaneous. Circular dichroism confirmed there was no alteration in the secondary structure of lactoferrin. The energy transfer efficiency (FRET) from lactoferrin to theaflavin was found to be approximately 50%, with a distance between protein and polyphenol of 2.44 nm. Molecular docking shows that the binding energy of lactoferrin–theaflavin monogallate interaction was −9.7 kcal mol−1. Theaflavin monogallate was bound at the central cavity of lactoferrin and formed hydrogen bonds with Gln89, Tyr192, Lys301, Ser303, Gln87, and Val250 of lactoferrin. Other residues, such as Tyr82, Tyr92, and Tyr192, were involved in hydrophobic interactions. The calculation of various molecular dynamics simulations parameters indicated the formation of a stable complex between protein and polyphenol. This study delineates the binding mechanism of polyphenol with milk protein and could be helpful in milk formulations and play a key role in the food industry.

We report a graphene oxide (GO) lamellar membrane with increased inter-layer spacing for efficient permeation of water molecules and heavy metal ions through nanoporous graphene oxide. The inter-layer spacing of the GO sheets in the lamellar structure was increased by introducing poly-aminophosphonic acid (APA) in between the GO sheets. We demonstrate experimentally, the use of a prepared membrane (GO–APA) by a SPE technique for the preconcentration and extraction of heavy metal ions by chelate formation and their determination by ICP-OES. We found that this sub-micrometer-thick membrane allows unimpeded permeation of water molecules through two-dimensional capillaries formed across the pores and by closely spaced graphene sheets. Compared to the bulk GO sorbent, GO–APA membrane offers enhanced sensitivity and permeability for heavy metal ions due to relatively large inter-layer spacing and high surface area (extraction phase) with a high number of active functional groups. The potential of this technique for the preconcentration and extraction of Pb(II), Cd(II) and Cu(II) is illustrated with the contaminated ground water and industrial waste water analysis. The detection limit achieved for studied ions was 1.1 ng L−1, under optimized experimental conditions. The co-existing ions did not hinders the extraction of trace heavy metal ions. Accuracy of the developed method was assessed by analyzing Standard Reference Materials. The Student's t test values were found to less than the critical Student's t value of 4.303 at the 95% confidence level. The method shows good precision as coefficients of variation for five replicate measurements were found to be 4–5%.

Novel ruthenium arene complexes of flavonoid derivatives were synthesized and characterized. The structure of complex 1 was determined by single-crystal X-ray crystallography. Ruthenium complexes display strong DNA interactions. Zero-order relativistic approximation (ZORA) was employed for the B3LYP/DFT calculation to validate the structures of 2 and 3. Frontier molecular orbital (FMO) analysis was performed for getting a trend of DNA binding propensity of the complexes. The ruthenium complexes 1–3 were tested against pathogens, viz. Pseudomonas aeruginosa PAO1, Chromobacterium violaceum ATCC 12472, and methicillin-resistant S. aureus (MRSA). The ruthenium complexes exhibited potential acting as biofilm inhibitors and showed significant activity as quorum sensing inhibitors. Scanning electron microscopy (SEM) and confocal microscopy visualized biofilm inhibition, and a substantial reduction in microcolonies was observed. Furthermore, essential quorum sensing (QS) regulated functions that play a crucial role in biofilm formation were also studied, i.e., exopolysaccharide (EPS) production and swarming motility. A significant reduction was recorded at the tested sub-MICs.

In the present study, ecofriendly green synthesized ZnO/CuO nanorods were prepared by using the stabilizing and reducing characteristics of the alginate biopolymer. The bionanocomposite (BNC) material was characterized by various sophisticated analytical tools such as Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy-energy dispersive X-ray spectroscopy, transmission electron microscopy, UV-visible spectroscopy, differential scanning calorimetry, and the Brunauer-Emmett-Teller (BET) method. The composition of ZnO/CuO@Alg BNC was found to be C (16.16 ± 0.42%), O (42.26 ± 1.87%), Cu (31.96 ± 1.05%), and Zn (9.62 ± 0.48%), which also supports the approximate 3:1 ratio of Cu2+ and Zn2+ taken as the precursor. The nanocrystalline spinel ferrite was found to have a BET specific surface area of 19.24 m2 g-1 with a total pore volume of 0.075 cm3 g-1 and 1.45 eV as the band gap energy (E g). Further, the material was applied for the photodegradation of p-nitrophenol (PNP) under the advanced oxidative process (AOP) under visible sunlight irradiation. The visible light radiation was used for the degradation of PNP under pH 2 conditions and resulted in 98.38% of the photocatalytic efficiency of the ZnO/CuO@Alg catalyst within 137 min of irradiation time. The photocatalytic reaction was best defined by the pseudo-first-order kinetics which involves the adsorption of the PNP molecule on the surface of the catalyst, thereby demineralizing it in the presence of advanced active •OH radicals. The values of rate constant for the pseudo-first-order model (k 1) were calculated as 0.013, 0.016, 0.019, 0.021, and 0.023 min-1 with half-life periods of 53.31, 43.31, 36.47, 33.00, and 30.13 min for 10-50 mg L-1 PNP concentrations. The presence of t-butyl alcohol decreases the photocatalytic efficiency, which suggests that the degradation of PNP was accomplished by the •OH oxidative radical.

It is important to understand the nature and mechanism of interaction of drugs with serum albumins as such interactions govern their pharmacokinetics and pharmacodynamics. Plumbagin is a natural phytocompound, mainly present in the bark of Plumbaginaceae family plants and it has numerous therapeutic potentials. In this study, the interaction of plumbagin with human serum albumin (HSA) was deciphered using an array of biophysical and computational tools. The UV–vis spectroscopy established the formation of plumbagin-HSA complex with binding constant as 2.32 × 104 M−1. Fluorescence spectroscopy revealed that there was static mode of quenching of HSA’s fluorescence by plumbagin. The binding constant obtained by fluorescence spectroscopy was of the similar order as in case of UV–vis spectroscopy. The negative value of ΔH° (−3.67) indicated an endothermic nature of the reaction and negative value of ΔG° (−6.40 to −6.58) confirmed that complexation of plumbagin to HSA was spontaneous. There was nearly one binding site in HSA for plumbagin. Titration of plumbagin to HSA in presence of site-specific markers showed that plumbagin interacted at sub-domain IIA of HSA, commonly known as Sudlow’s site I. Moreover, the binding resulted in changes in microenvironment of tryptophan while of tyrosine residues remained approximately unchanged. This interaction also resulted in decrease of α-helical content of the studied serum protein. FRET calculations revealed that distance between plumbagin and HSA’s fluorophore (Trp214) was 2.27 nm. Finally, molecular docking studies substantiated the in vitro finding. Plumbagin formed hydrogen bond with Lys199 and Arg257 of HSA. Additionally, Arg222, His242, and Ala261 interacted via van der Waals forces and Leu238, Leu260, Ile264, Ile290, and Ala291 of HSA interacted with plumbagin through hydrophobic forces.

Herein, different types of metal-containing ionic liquid (IL) complexes and various metal oxide-based nanocatalysts have been successfully prepared (from ionic liquids) and applied for the oxidative desulfurization (ODS) of dibenzothiophene (DBT). The ILs complexes are comprised of N,N′-dialkylimidazolium salts of the type [RMIM-Cl]2[MCln], where [RMIM+] = 1 alkyl-3-methylimidazolium and M = Mn(II)/Fe(II)/Ni(II)/Co(II). These complexes were prepared using an easy synthetic route by refluxing the methanolic solutions of imidazolium chloride and metal chlorides under facile conditions. The as-prepared complexes were further used as precursors during the ionothermal and chemical synthesis of various metal oxide-based nanocatalysts. The resulting ILs salts and metal oxides NPs have been characterized by FT-IR, TGA, XRD, SEM, and TEM analysis. The results indicate that thermal and chemical treatment of ILs based precursor has produced different phases of metal oxide NPs. The calcination produced α-Fe2O3, Mn3O4, and Co3O4, NPs, whereas the chemical treatment of the ILs salts have led to the production of Fe3O4, Mn2O3, and α-Co(OH)2. All the as-prepared salts and metal oxide-based nanocatalysts were used as catalysts towards ODS of dibenzothiophene. The oxidation of dibenzothiophene was performed at atmospheric conditions using hydrogen peroxide as the oxygen donor. Among various catalysts, the thermally obtained metal oxide NPs such as α-Fe2O3, Mn3O4, and Co3O4, have demonstrated relatively superior catalytic activities compared to the other materials. For example, among these nanocatalysts, α-Fe2O3 has exhibited a maximum conversion (∼99%) of dibenzothiophene (DBT) to dibenzothiophene sulfone (DBTO2).

Enterohemorrhagic Escherichia coli infection is associated with gastrointestinal disorders, including diarrhea and colorectal cancer. Although evidences have established the involvement of E. coli in the growth of colon cancer, the molecular mechanisms of carcinogenesis of cancer growth and development are not well understood. We analyzed E. coli protein targeting in host cell organelles and the implication in colon cancer using in silico approaches. Our results indicated that many E. coli proteins targeted the endoplasmic reticulum (ER), ER membranes, Golgi apparatus, Golgi apparatus membranes, peroxisomes, nucleus, nuclear membrane, mitochondria, and mitochondrial membrane of host cells. These targeted proteins in ER, Golgi apparatus, peroxisomes, nucleus, and mitochondria may alter the normal functioning of various pathways including DNA repair, apoptosis, replication, transcription, and protein folding in E. coli-infected host cells. The results of the current in silico study provide insights into E. coli pathogenesis and may aid in designing new preventive and therapeutic strategies.

Carbon nanomaterials exhibit exceptional properties and broad horizon applications, where graphene is one of the most popular allotropes of this family due to its astounding performance in every stratum vis-à-vis other classical materials. The large surface area of 2630 m

Methyl ammonium antimony iodide (MA3Sb2I9) perovskite-like materials have gained enormous attention from the scientific community because of their excellent aerobic stability, good optical properties, and less-toxic nature. Herein, we report on the simulation of FTO/TiO2/MA3Sb2I9/spiro-OMeTAD via solar cell capacitance (SCAPS) software. The thickness of the absorber layer, hole-transport layer, or electron-transport layer may significantly impact the photovoltaic performance of the perovskite solar cells (PSCs). In this connection, the thickness of the absorber layer, hole-transport layer, or electron-transport layer was varied during the simulation process and the optimized PSCs demonstrated a good efficiency of 14.90% including an excellent open circuit voltage (Voc) of 1.41 V. Furthermore, we also fabricated MA3Sb2I9-based PSCs and their photovoltaic performance was evaluated. The fabricated PSCs showed a reasonably good efficiency of 1.27% and Voc of 0.51 V.

Hg(ii) ion adsorption onto an MoS2 surface.

Primary central nervous system lymphoma (PCNSL) presenting with atypical radiological findings often leads to delayed diagnosis. We aim to characterize the radiological features and apparent diffusion coefficient (ADC) values of PCNSL with atypical neuroimaging presentation in our local population. We retrospectively reviewed all patients with histological diagnosis of CNS lymphoma at our tertiary center from 2005 to 2016. We screened all initial pre-treatment MRIs and excluded cases with typical imaging findings of contrast-enhancing lesions without intra-lesional susceptibility and central non-enhancement. Additional exclusion criteria included (i) relapsed PCNSL, (ii) secondary CNS lymphoma, and (iii) positive HIV status. Two independent raters scored MRI and CT scans at presentation. We computed ADC values in the tumors by 2 methods: single region of interest (ROI1) and multiple ROI (ROI2). Sixteen (25.4%) of 63 patients with CNS lymphoma met inclusion criteria. There were 8 men; median age was 61 (range 22–81) years. Histological diagnoses were diffuse large B cell lymphoma (n = 14) and intravascular lymphoma (n = 2). Fifteen (93%) patients had enhancing lesions (5 solitary; 10 multifocal); most enhancing lesions had T1 hypointense (67%) and T2 mixed (53%) signals, and 6 (40%) had central non-enhancing regions. Nine (56%) patients had lesions with susceptibility. Using the ROI methods, median values for minimum ADC and mean ADC ranged 0.65–0.71 × 10–3 mm2/s and 0.79–0.84 × 10–3 mm2/s respectively. PCNSL with atypical radiological features represented one-fourth of our histologically diagnosed lymphoma cases; low ADC values in atypical lesions should prompt clinicians to consider early biopsy for definitive diagnosis.

The green mechanism for the synthesis of nanoparticles and their application to the wastewater treatment is of inordinate curiosity to the research community. Herein we outline a novel method for the synthesis of silver nanoparticles via a green route using alginate-guar gum blend (GG-Alg@Ag) and their application to degrade methylene blue (MB) dye. The synthesized material was characterized by FTIR, XRD, SEM-EDX, TEM, TGA-DTG, AFM, and UV-vis techniques. A combination of RSM and CCD was employed to compute the system and optimized values of various interacting parameters such as exposure time (120 min), pH (4.98), dye concentration (194 mg L−1), and catalyst dose (0.07 g) with a photodegradation capacity of 92.33% and desirability 1.0. The mechanism of degradation reaction was best elucidated by the pseudo-second-order model suggesting chemical deposition of MB on the GG-Alg@Ag surface through followed by the reduction mechanism in the occupancy of visible light. The optical studies indicated a value of 2.5 eV by Tauc's plot for bandgap energy (Eg) for GG-Alg@Ag bionanocomposite.

A series of phenanthroimidazole (PI) derivatives (M1–M3): 2-phenyl-1H-phenanthro [9,10-d]imidazole (M1), 2-anthryl-1H-phenanthro[9,10-d]imidazole (M2), and 2-pyrenyl-1H-phenanthro[9,10-d]imidazole (M3) were synthesized and characterized using various spectroscopic techniques. The fluorescence quenching studies or sensing properties of the molecules M1–M3 with picric acid (PA) were studied. The molecules (M1–M3) exhibit strong fluorescence with a peak emission wavelength at 386, 486 and 456 nm. This emission gets quenched with the addition of PA. The mechanism of fluorescence quenching involves proton transfer from PA to M in the ground state, followed by the formation of a complex between the cation (M+) and picrate anion (PA−). The proton transfer breaks the conjugation inside the imidazole ring which in turn leads to loss of fluorescence. The proof of proton transfer was evident from the single X-ray crystal structure of the co-crystals (M1+–PA− and M3+–PA−) and their Hirshfeld surface analysis. Time-resolved fluorescence measurements reveal that quenching is static. The complex formation constant (Ks) and life-time for all the molecules are measured.

Current exanimation reports, green fabrication of silver doped TiO2 nanoparticles (Ag/TiO2) using aqueous extract of Acacia nilotica as bio-reductant and assess its potential as antimicrobial and anticancer agent. The obtained spherical Ag/TiO2 were characterized by various analytical techniques including FTIR, (XRD), (FE-SEM EDS), and (TEM). Synthesized Ag/TiO2 demonstrated broad spectrum antibacterial and anticandidal activity. The order of antimicrobial activity was found to be E. coli > C. albicans > MRSA > P. aeruginosa. In addition, cytotoxicity and oxidative stress of Ag/TiO2 nanoparticles in (MCF-7) cells was also investigated. Outcomes of MTT assay showed concentration dependent reduction in cell viability. Further, synthesized NPs reduced the level of glutathione, induced ROS generation and lipid peroxidation in the treated cells. Therefore, it is envisaged that these spherical nanoparticles may be exploited in drug delivery, pharmaceutical, and food industry. Keywords: Green synthesis, Ag/TiO2, Antimicrobial activity, Anticancer activity, MCF-7, Oxidative stress

Multi-drug resistance (MDR) poses a serious threat in the management of infectious diseases. Slow development of antibiotics and acquirement of resistance mechanisms has led the researchers to focus on development of novel chemotherapeutic agents with broad-spectrum activity having multiple sites of action. Till date, nanoparticles are proven to be a good alternative in management of MDR at least under laboratory conditions. In this study, dextrin was used for eco-friendly green synthesis of silver nanoparticles grafted by poly (methyl methacrylate). The nanoparticles were characterized using UV–vis spectroscopy, FTIR, XRD, SEM, EDX and TEM. The synthesized nanoparticles (PMMA-g-Dex@Ag) were then evaluated for antimicrobial and antibiofilm efficacy on multi-drug resistance bacterial and fungal pathogens. PMMA-g-Dex@Ag proved to be good bacteriostatic even at 4 μg/ml. The minimum inhibitory concentration (MIC) against C. albicans was found to be 16 μg/ml. Moreover, the biofilms of all tested pathogens were reduced by approximately more than 70% in presence of highest tested sub-MIC. Inhibition of exopolysaccharides (EPS) secretion supported the biofilms data and deciphered a possible mode of action. Therefore, such green synthesized nanoparticles can be used as an alternative in management of MDR infection at least for tropical application after careful in vivo validation.

In the past few years, the design and fabrication of highly sensitive and selective electrochemical sensors have received enormous attention from electrochemists. Acetaminophen is an important drug that is used as an antipyretic and analgesic drug throughout the world. It is important to monitor the accurate amount of acetaminophen. Herein, we have prepared sulfur-doped reduced graphene oxide (S@rGO) using simple strategies. The morphological feature of the S@rGO was characterized by using scanning electron microscopy whereas phase purity and formation of S@rGO were authenticated by X-ray diffraction. Further, the glassy carbon electrode was modified using S@rGO as an electrode modifier and employed as an acetaminophen sensor (S@rGO/GCE). This modified sensor (S@rGO/GCE) demonstrates a reasonable detection limit of 0.07 µM and a sensitivity of 0.957 µA/µMcm2.

Recently, the electrochemical sensing approach has attracted materials/electrochemical scientists to design and develop electrode materials for the construction of electrochemical sensors for the detection of para-nitrophenol (4-NP). In the present study, we have prepared a hybrid composite of MnO2 and rGO (MnO2/rGO) using a hydrothermal approach. The morphological features of the prepared MnO2/rGO composite were studied by scanning electron microscopy, whereas the phase purity and formation of the MnO2/rGO composite were authenticated via the powder X-ray diffraction method. Energy-dispersive X-ray spectroscopy was also employed to analyze the elemental composition of the prepared MnO2/rGO composite. In further studies, a glassy carbon electrode (GCE) was modified with MnO2/rGO composite (MnO2/rGO/GCE) and explored as 4-nitrophenol (4-NP) sensor. The fabricated MnO2/rGO/GCE exhibited a reasonably good limit of detection of 0.09 µM with a sensitivity of 0.657 µA/µMcm2. The MnO2/rGO/GCE also demonstrates good selectivity, stability and repeatability in 50 cycles.

The new 3D coordination polymer (CP) [Mn(L)(HCOO)]n (Mn-CP) [L = 4-(pyridin-4-ylcarbamoyl)benzoate] was synthesised via a hydrothermal reaction using the pyridyl amide functionalized benzoic acid HL. It was characterized by elemental, FT-IR spectroscopy, single-crystal and powder X-ray diffraction (PXRD) analyses. Its structural features were disclosed by single-crystal X-ray diffraction analysis, which revealed a 3D structure with the monoclinic space group P21/c. Its performance as an electrocatalyst for oxygen reduction (ORR), oxygen evolution (OER), and hydrogen evolution (HER) reactions was tested in both acidic (0.5 M H2SO4) and alkaline (0.1 M KOH) media. A distinct reduction peak was observed at 0.53 V vs. RHE in 0.1 M KOH, which corresponds to the oxygen reduction, thus clearly demonstrating the material’s activity for the ORR. Tafel analysis revealed a Tafel slope of 101 mV dec−1 with mixed kinetics of 2e− and 4e− pathways indicated by the Koutecky–Levich analysis. Conversely, the ORR peak was not present in 0.5 M H2SO4 indicating no activity of Mn-CP for this reaction in acidic media. In addition, Mn-CP demonstrated a noteworthy activity toward OER and HER in acidic media, in contrast to what was observed in 0.1 M KOH.

Copper compounds are promising candidates for next-generation metal anticancer drugs. Therefore, we synthesized and characterized a formate bridged 1D coordination polymer [Cu(L)(HCOO)2]n, (L = 2-methoxy-6-methyl-3-((quinolin-8-ylimino)methyl)chroman-4-ol), PCU1, wherein the Cu(ii) center adopts a square pyramidal coordination environment with adjacent CuCu distances of 5.28 A. Primarily, in vitro DNA interaction studies revealed a metallopolymer which possesses high DNA binding propensity and cleaves DNA via the oxidative pathway. We further analysed its potential on cancerous cells MCF-7, HeLa, A549, and two non-tumorigenic cells HEK293 and HBE. The selective cytotoxicity potential of PCU1 against A549 cells driven us to examine the mechanistic pathways comprehensively by carrying out various assays viz, cell cycle arrest, Annexin V-FTIC/PI assay, autophagy, intercellular localization, mitochondrial membrane potential 'MMP', antiproliferative assay, and gene expression of TGF-β and MMP-2.