Construction of Ag/CdZnS QDs nanocomposite for enhanced visible light photoinactivation of Staphylococcus aureus

With increasing use of antibiotics, the development of antibiotic-resistant pathogens poses a serious threat to human health and the environment. Photocatalytic inactivation of these harmful pathogens is one of the novel and non-antibiotic treatments. The study fabricated Ag NPs decorated CdZnS QDs via a facile and biological co-precipitation method using L. camara plant extract as a green alternative to treat the toxic chemicals. The fabricated Ag/CdZnS QDs (NCs) were prepared for the efficient treatment of antibiotic-resistant pathogens as they raise a major global concern. The fabricated NCs were characterized with various characterization techniques to verify its physicochemical properties. The fabricated NCs have shown excellent photo-sterilization performance of 97 % against S. aureus. The excellent activity was attributed to the decoration of Ag NPs on CdZnS QDs as it helped in shortening band gap, improved visible light absorption ability, increased active sites, and boosted photogenerated electron/hole pairs stability. Radical trapping experiment and ESR analysis indicated the involvement of •OH and h+ in the photoinactivation of bacteria. The photo sterilization reaction of NCs was carried out under different environmental conditions, including light and dark conditions and different pH conditions. The experiment was carried out in sewage-treated water in order to test the real-time application, and the fabricated NCs achieved excellent 95.9 % photo-inactivation of S. aureus cells in sewage treated water and the Chemical Oxygen Demand (COD) of the system was increased after photo inactivation treatment. The fabricated NCs have also shown excellent reusable efficiency of 95% after six runs and the photostability and anti-corrosive nature of NCs were confirmed. The study provides an insight for the employment of photocatalysis for the sterilization of pathogens in real time aquatic environment across the globe.

Enhanced visible light driven photodegradation of rifampicin and Cr(VI) reduction activity of ultra-thin ZnO nanosheets/CuCo2S4QDs: A mechanistic insights, degradation pathway and toxicity assessment

In this study, we focused on fabrication of porous ultra-thin ZnO nanosheet (PUNs)/CuCo2S4 quantum dots (CCS QDs) for visible light-driven photodegradation of rifampicin (RIF) and Cr(VI) reduction. The morphology, structural, optical and textural properties of fabricated photocatalyst were critically analyzed with different analytical and spectroscopic techniques. An exceptionally high RIF degradation (99.97%) and maximum hexavalent Cr(VI) reduction (96.17%) under visible light was achieved at 10 wt% CCS QDs loaded ZnO, which is 213% and 517% greater than bare ZnO PUNs. This enhancement attributed to the improved visible light absorption, interfacial synergistic effect, and high surface-rich active sites. Extremely high generation of ●OH attributed to the spin-orbit coupling in ZnO PUNs@CCS QDs and the existence of oxygen vacancies. Besides, the ZnOPUNs@CCS QDs, forming Z-scheme heterojunctions, enhanced the separation of photogenerated charge carriers. We investigated the influencing factors such as pH, inorganic ions, catalyst dosage and drug dosage on the degradation process. More impressively, a stable performance of ZnO PUNs@CCS QDs obtained even after six consecutive degradation (85.9%) and Cr(VI) reduction (67.7%) cycles. Furthermore, the toxicity of intermediates produced during the photodegradation process were assessed using ECOSAR program. This work provides a new strategy for ZnO-based photocatalysis as a promising candidate for the treatment of various contaminants present in water bodies.

Construction of p-n-p nano heterojunction through coupling La2O3, (BiO)2CO3 and Ag3PO4 for effective photocatalytic degradation of doxycycline: Insights into mechanism, pathway and intermediate toxicity evaluation

The present work is centred around the development of La2O3/(BiO)2CO3/Ag3PO4 (LBA), a p-n-p nano-heterojunction to photodegrade doxycycline under visible light irradiation. Here, ultrasonication assisted co-precipitation method was employed to synthesize the photocatalyst. The photocatalyst was characterized using different analysis such as SEM, TEM, elemental mapping, XRD, XPS, FTIR, Raman, BET, DRS, PL and EIS which confirmed the successful fabrication of LBA and their excellent ability to refrain the e-/h+ recombination owing to the construction of the heterojunction. LBA was found to degrade DOX by 91.75 % with the high mineralization of 87.23%. The impact of the reaction parameters influencing the photodegradation process including the concentration of the NCs and DOX, pH and the influence of the commonly present anions were studied. The stability and reusability of the LBA was assessed through subjecting it to four cycles of photodegradation of DOX. In addition, the recovered LBA was characterized through XPS and XRD analysis to confirm the particles stability and reusability. The active participation of the photogenerated charges and the reactive oxygen species were identified through the scavenging assay and ESR analysis. Further, GC-MS/MS analysis was performed to put forward a plausible photodegradation pathway. The toxicity of the end products as well as the intermediates was predicted through ECOSAR software.

Unravelling the enhanced rifampicin photocatalytic degradation over green-synthesized SrO2@SnIn4S8 p-n heterojunction: Pathway, toxicity evaluation and mechanistic insights

In recent years, the discharge of pharmaceutical drugs into aquatic ecosystems has become a growing concern, posing a significant threat to aquatic life. In response to this environmental challenge, advanced oxidation processes have gained prominence in wastewater treatment due to their efficacy in eliminating pharmaceutical pollutants and their potential for reusability. In this study, we have fabricated SnIn4S8 coupled SrO2 nano-heterojunction (NH) using a greener co-precipitation approach using leaf extract derived from Acaphyla wilkesiana. The resulting NH exhibited exceptional photocatalytic activity against rifampicin (RIF), achieving a remarkable 97.4% degradation under visible light, surpassing the performance of its individual components. The morphological characteristics of the NH were thoroughly analyzed through SEM, TEM, XRD, and XPS techniques, while EIS, DRS, and BET techniques provided valuable insights into its photocatalytic and optical properties. Furthermore, radical scavenging assays and ESR analysis identified hydroxyl radicals (•OH) and superoxide radicals (O2•-) were the species contributing to the visible light-driven photocatalytic degradation. The study also elucidated the potential degradation pathways and intermediates of RIF through GC-MS analysis. Additionally, the toxicity of the produced intermediates was assessed using the ECOSAR model. The findings have significant implications for the treatment of pharmaceutical pollutants and underscore the importance of eco-friendly synthesis methods in addressing environmental challenges.

Interstitial decoration of Ag linking 3D Cu2O octahedron and 2D CaWO4 for augmented visible light active photocatalytic degradation of rifampicin and genotoxicity studies

A morphological oriented highly active Cu2O-Ag-CaWO4 (CAC) nano-heterojunction was fabricated for the visible light driven degradation of rifampicin (RFP). Octahedron shaped Cu2O being a base material, where the Tagetes shaped CaWO4 and Ag were embedded on it. The shape-controlled morphology of Cu2O and CaWO4 as well as Ag decoration influence high degree of adsorption of RFP and interfacial charge transfer between the nano-heterojunction. Further, the larger specific surface area (129.531 m2/g) and narrow band gap energy (2.57 eV) of CAC nano-heterojunction than the controls support the statement. Positively, CAC nano-heterojunction following Z-scheme-type charge transport mechanism attained 96% of RFP degradation within 100 min. O2•- and •OH are the primarily involved reactive oxidation species (ROS) during the photocatalytic reactions, determined by scavenger study and ESR analysis. The stability and reusability of the CAC nano-heterojunction was assessed through performing cyclic experiment of RFP degradation and it holds 96.8% of degradation even after 6th cycle. The stability of CAC nano-heterojunction after photodegradation was further confirmed based on crystalline pattern (XRD analysis) and compositional states (XPS analysis). Intermediates formed during RFP degradation and its toxicity was discovered by using GC-MS/MS and ECOSAR analysis respectively. The end-product toxicity against bacterial system and genotoxicity of CAC nano-heterojunction against Allium cepa were evaluated and the results were seemed to have no negative causes for the aquatic lives.

Interfacial coupling of CuFe2O4 induced hotspots over self-assembled g-C3N4 nanosheets as an efficient photocatalytic bacterial disinfectant

Most bacterial disinfectants contain high levels of extremely toxic and environmental hazardous chemicals, which pose a significant threat to the ecosystem. Semiconductor photocatalysis exhibits attractive prospects as an emerging greener technology for waste water disinfection. However, the fast recombination of charge carriers limits its practical application. Herein, self-assembled polymeric feather-like g-C3N4 (GCN) nanosheets modified with ferromagnetic CuFe2O4 (CFO) nanospheres were successfully applied as a reusable visible light photocatalytic disinfectant. As expected, the g-C3N4/CuFe2O4 (GCF) nanohybrid displayed superior photocatalytic inactivation efficiency of 0.157log within 120 min towards Escherichia coli DH5α (E. coli) compared with pristine GCN and CFO. The characterization results revealed the synergistic heterostructure interfaces, high surface area, and the transformative self-assembly of GCN to feather-like structure providing a rich active site for improved charge separation efficiency, and wide spectral response, therefore the superior performance of GCF. The radical trapping assay proclaimed that both O2•- and •OH radical played major role in the photocatalytic inactivation among the other reactive oxygen species (ROS). Furthermore, the chemical oxygen demand (COD), protein estimation, and DNA estimation assay results validated the cell damage caused by the photocatalyst. Besides that, GCN showed applicability in real-time wastewater samples with improved efficiency than in the saline solution. The excellent magnetic characteristics facilitated the recycling of the catalyst with insignificant leaching, magnetic induction, and distinguished separation. The results of this work signify the well-designed GCF as a high-performance and reusable photocatalyst for real-world pathogenic bacterial disinfection operations.

A two-generational reproductive study to assess the effects of Juglans regia on reproductive developments in the male and female rats

Environmental pollutants and lifestyle severely threaten human and animal health, leading to disturbances of various functions, including infertility. So, exploring a safe treatment that could effectively reverse infertility remains a challenge. The current study was intended to explore the fertility-enhancing effect of Juglans Regia oil in two successive generations of rats; F0 and F1. J. Regia oil was initially tested for in vitro antioxidant assay via ROS and DPPH, followed by in vivo toxicity testing. In the fertility assessment, eighteen pairs of male and female rats (n=36, 1:1, F0 generation) were divided into three groups and dosed with 1 mL/kg and 2 mL/kg daily of J. Regia oil and saline, respectively, up to pre-cohabitation, cohabitation, gestation and lactation periods. The reproductive performance, including body weight, live birth index, fertility index, and litter size, was assessed. Hormonal and antioxidant markers of F1 generations were assessed with the histopathological evaluation of male and female organs. The oil of J. Regia showed great antioxidant potential (P < 0.05) in DPPH (1,1-diphenyl-2-picrylhydrazyl) and ROS (Reactive Oxygen Species) methods (P<0.05). The continued exposure of the F0 and F1 generations to J. Regia oil did not affect body weight, fertility index, litter size, and survival index. We have found pronounced fertility outcomes in both genders of F0 and F1 generations with J. Regia 2 mL/kg/day in comparison to the control. Results showed that J. Regia significantly increased (P < 0.05) luteinizing hormone (LH), plasma testosterone, follicular stimulating hormone (FSH), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities in both generations. Histology of both generations reveals improved spermatogenesis and folliculogenesis with enhanced architecture. Altogether, the present results suggest that J. Regia improved fertility in both male and female rats by improving hormonal activities and oxidative stress.

Congregating Ag into γ-Bi2O3 coupled with CoFe2O4 for enhanced visible light photocatalytic degradation of ciprofloxacin, Cr(VI) reduction and genotoxicity studies

The work attempts to construct a highly effective γ-Bi2O3/CoFe2O4/Ag visible active photocatalyst for the enhanced degradation of ciprofloxacin (CIP) and Cr(VI) reduction. γ-Bi2O3/CoFe2O4/Ag photocatalyst was prepared by simple solid phase and co-precipitation methods. The nanosphere shaped CoFe2O4 photocatalyst are embedded on top of γ-Bi2O3 nanotriangle. The addition of Ag into γ-Bi2O3/CoFe2O4 heterojunction primitively facilitates the photocatalytic activity in higher rate. The quantitative analysis of photocatalyst possesses to have lower e-/h+ recombination rate compared to its counterparts. The prepared γ-Bi2O3/CoFe2O4/Ag photocatalyst showed 96.6% degradation of CIP in 220 min and 99.2% reduction of Cr(VI) in 120 min. Additionally, γ-Bi2O3/CoFe2O4/Ag showed outstanding recyclability and long-term stability with a degradation efficiency of 96.5% even after six cycles. The intermediate products formed were identified and the degradation pathway was elucidated by gas chromatography-mass spectrometry analysis. Total organic carbon measurement was carried over to assess the efficiency of complete degradation and the removal percentage was found to be 98%. The end product toxicity study towards bacteria was proven to have less toxicity level when compared to parent compound. Lastly, the genotoxicity of γ-Bi2O3/CoFe2O4/Ag photocatalyst was tested in Allium cepa and the results confirmed to have no cause of toxicity impacts. Overall, the work not only tends to provide a highly visible active γ-Bi2O3/CoFe2O4/Ag photocatalyst, but also attributes to have no further negative imprints in the environment.

Synergistic visible light assisted photocatalytic degradation of p-chlorophenol and rifampicin from aqueous solution using a novel g-C3N4 quantum dots incorporated α-MoO3 nanohybrid - Mechanism, pathway and toxicity studies

In this work, a simple g-C3N4 quantum dots enriched MoO3 nanohybrid was formulated for the synergistic photocatalytic degradation of an industrially active organic pollutant, p-chlorophenol (PCP) and a widely prescribed antibiotic, rifampicin (RIF). The nanohybrid was synthesised via a facile ultrasonic assisted hydrothermal method and characterized using various characterization analysis. The efficient Z-scheme charge transfer of the nanohybrid resulted in the elimination of 98% PCP and 89% RIF under visible light with a rate constant of 0.012 and 0.006 min-1 respectively. The photocatalysis was attributed to the formation of both hydroxyl (OH•) and superoxide (O2•-) radicals in the resulting nanohybrid. The intermediates formed in the course of reaction were estimated through gas chromatography-mass spectroscopy/mass spectroscopy (GC-MS/MS) analysis and a suitable degradation pathway was constructed. The structural stability and reusability of the nanohybrid was affirmed through X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis to outweigh the industrial potential of the catalyst, with 85% PCP and 80% RIF removal efficiency after six cycles of degradation. In addition, the mineralization of the pollutants was confirmed by total organic carbon analysis. Further, the toxicity of the drug and the formed intermediates was determined using ecological structure activity relationships (ECOSAR) software. On the whole, this work provides an excellent insight for the development of environment-friendly materials in a large scale for the degradation of water-based pollutants.

'One Health´ approach to end zoonotic TB

Mycobacterium bovis has a wide host range causing TB in animals, both in wildlife and cattle (bovine TB bTB), and in humans (zoonotic TB zTB). The real burden of bovine and zoonotic TB (b/zTB) remains unknown due to diagnostic challenges. Although progress has been made to reduce the burden of TB, b/zTB has been neglected in low- and middle-income countries (LMICs) with little improvement in prevention, diagnosis or treatment. Using Tanzania as a case study, because of its high TB burden, large wildlife diversity and wide reliance on livestock, we developed an approach to comprehensively estimate the burden and implement multidisciplinary actions against b/zTB. We performed a review of the literature on b/zTB, but there is a lack of available data on the b/zTB burden in Tanzania and, notably, on epidemiological indicators other than incidence. We propose a five-action programme to address b/zTB in Tanzania, and we believe our proposed approach could benefit other LMICs as it operates by implementing and strengthening surveillance and health delivery. The resulting knowledge and system organisation could further prevent and mitigate the effects of such conditions on human and animal health, livestock production, population livelihood and the economy.

Sunlight promoted self-fenton photodegradation and pathway of doxycycline: Interactive effects of nanomaterial on bean plant and its genotoxicity against Allium cepa

Photocatalytic induction of electron/hole recombination, surface property and light response ability effectively enhance the photocatalytic activity of nanomaterial. In this work, the effective charge carrier separating Sn/Mn-ZnFe₂O₄-CdFe₂O₄-Ag₃PO₄ Quantum dots (M/SZFO-CFO-AP QDs) was fabricated for photocatalytic degradation of doxycycline (doxy) antibiotic. The result showed enhanced photocatalytic activity of doxy and the degradation efficiency of doxy was about 98.8% in short span of time. The calculated WH plot and urbach energy of prepared photocatalyst exhibited evidence for the prevalence of point defects and its contribution to efficient charge separation and transferability. The total organic carbon (TOC) removal was found to be 98.9%, which depicts the complete mineralization of doxy. The synergetic charge transfer of n-p-n heterojunction enables the effective removal of doxy under visible light irradiation. Further, the genotoxicity study was determined by interacting the SZFO-CFO-AP QDs with Allium Cepa. The results depict that SZFO-CFO-AP QDs show lower toxicity level and there were no trace of defective mitotic phases and micro nuclei. Further, the progression and development of bean plant was determined after treating with prepared nanomaterials and the result showed the enhanced growth in SZFO-CFO-AP QDs treated bean plant compared to the counterparts. Therefore, the prepared SZFO-CFO-AP QDs was can be used as an environmental friendly photocatalyst for effective treatment of antibiotic present in the water bodies.

Self-propelled nanojets an interfacial Schottky junctions modulated oxygen vacancies enriched for enhanced photo-Fenton degradation of organic contaminant: Improving H2O2 generation, Fe3+/Fe2+ cycle and enhancing plant metabolism

The study reports an innovative approach on sunlit driven heterostructure photocatalytic generation of H₂O₂ and removal of cefixime. In the present work, we have fabricated Mn/Mg doped CoFe₂O₄ modified CaCr₂O₄ decorated by Ag₃PO₄ quantum dots (Ag₃PO₄ QDs), a p-n-p nano heterojunction. The study promotes the photocatalytic production of H₂O₂ and self-Fenton photocatalytic degradation of cefixime. Egg white-assisted synthesis of Mn-doped CoFe₂O₄ causes the lattice oxygen defect, which enhances the photocatalytic activity. Lattice oxygen defect enable the adsorption of O₂, which enable the conversion of •O² in the valence band of CoFe₂O₄ for the endogenous production of H₂O₂. The higher in the surface area enhance the photocatalytic activity under visible light irradiation. Mn-CoFe₂O₄-CaCr₂O₄-Ag₃PO₄ QDs enables the complete photocatalytic degradation of cefixime (99.9%) and the complete removal was determined by total organic carbon (TOC) removal and it was around 99.4%. Meanwhile the photocatalytic degradation pathway of cefixime was determined by LC-MS/MS. Reusability of the nano heterojunction was determined by six cycle test, and the reusability of the nano heterojunction was 99.8%. Further, the toxicity of the nanomaterial was studied in maize plant and the results shows that the nanoheterojunction enhances the maize growth. The study systematically reveals the robust activity of nano heterojunction for sustainable water treatment.

Eco-friendly cubic-ZnS coupled Cu7S4 spines on chitosan matrix: Unravelling defect-engineered nanoplatform for the photodegradation of p-chlorophenol

Novel ZnS-Cu₇S₄ nanohybrid supported on chitosan matrix, as an ideal photocatalyst, was fabricated by the sonochemical method wherein high-resolution transmission electron microscopy (HRTEM) and X-ray powder diffraction (XRD) analysis confirmed the co-existence of both ZnS and Cu₇S₄; presence of vacancy sites in ZnS was verified by electron paramagnetic resonance (EPR) analysis and their introduction could promote two-photon excitation facilitated visible light response and charge transport/separation. The type II interface is formed in the ZnS-Cu₇S₄/Chitosan heterojunction owing to interstitial states that promote charge separation. The ZnS-Cu₇S₄/Chitosan was used for the photodegradation of a pharmaceutical pollutant, p-chlorophenol (PCP); over 98.8% of PCP photodegradation was achieved under visible-light irradiation where the ensued ·O₂^- and ·OH serve a key role in the photodegradation of PCP. In vitro cytotoxicity studies substantiated that the ZnS-Cu₇S₄/Chitosan is nontoxic to the ecosystem and human beings and endowed with promising photodegradation properties and accessibility via an environmentally friendly design, bodes well for its potential remediation applications.

Novel insight on chemo-specific detection of toxic environmental chromium residues existing as recalcitrant Cr(III)-carboxyl complexes using plasmonic silver nanoplatform bi-functionalized with citrate and PVP

Chromium (Cr) is a toxic environmental pollutant that majorly exists in trivalent and hexavalent forms. Though Cr(VI) is more dangerous than Cr(III), the trivalent Cr forms complexes with environmentally-available organic molecules. This makes them potentially harmful and difficult to detect. In this study, we have designed an ultrasensitive plasmonic nanosensor using citrate and PVP functionalized Ag nanoparticles (Ag-citrate-PVPNPs) for the detection of trivalent chromium organic complexes such as Cr(III)-EDTA (Cr-E), Cr(III)-acetate (Cr-A), Cr(III)-citrate (Cr-C) and Cr(III)-tartrate (Cr-T). The nanoparticles (NPs) were structurally characterized by XRD, SEM, HRTEM, SAED, EDX and elemental mapping. The citrate and PVP molecules played a vital role in the detection mechanism and stability of the sensor. Upon detection, the yellow-colored Ag-citrate-PVP NPs turned into different shades of brown depending on the type of the Cr complex and concentration. It was accompanied by diminishing and/or shifting UV-Visible absorbance peaks due to the aggregation of Ag-citrate-PVP NPs. Further, a linear relationship was observed between absorbance reduction and analyte concentration. The selectivity tests showed that the sensor was non-functional to other metal ions and inorganic anions. The sensor was optimized using pH and temperature studies. The mechanism of detection was elucidated with the help of characterization techniques such as Raman spectroscopy, FTIR, XPS and UV-visible spectrophotometer. The limit of detection (LOD) was found to be 3.29, 4.87, 1.76 and 1.79 nM for Cr-E, Cr-A, Cr-C and Cr-T complexes respectively. This study provides a rapid and sensitive approach for the detection of multiple Cr(III)-organic complexes present in an aqueous solution.

Construction of S-scheme CdS/CuFe2O4 heterojunction with suppressed charge recombination for enhanced visible light driven photocatalytic activity

Effective interfacial engineering to fabricate a suitable nano-photocatalyst for environmental remediation is of high demand. The magnetic nanocomposite is a potential candidate for reusability and recovery from treated wastewater. The...

Enhanced photodegradation of rifampicin and co-trimoxazole by ZnO/ZnMn2O4/ZnS-PVA and its genotoxicity studies on Allium cepa

Oxygen vacancies and its associated defect states have a great influence on the electronic and structural aspects of semiconductor photocatalysts, yet there is paucity of investigations about the influence of the defect states on their photocatalytic properties. Herein, this study reports the hierarchical fabrication of oxygen vacancy enriched ZnO/ZnMn₂O₄/ZnS-PVA nanocomposite (NCs) for the enhanced photodegradation of rifampicin and co-trimoxazole. The formation of lattice expansion induced oxygen vacancies and its associated Urbach tail energy, and n-p-n heterojunction-based S-scheme charge transfer path synergistically contributed to the boosted photocatalytic performance of the as prepared NCs. The photocatalytic performance of the nanomaterial towards rifampicin and co-trimoxazole has been determined to be 80% and 90% under visible light irradiation, respectively. Furthermore, various operating parameters including the concentration of NCs and drug, pH and interference of various ions have been evaluated. The degraded product intermediates have been elucidated by GC-MS analysis. The toxicity of the as-prepared nanomaterials has been evaluated by treating the samples with root tips of Allium cepa, where the NCs was found to be non-toxic. The study provides a new-fangled insight on the preparation and fabrication of non-toxic and defect rich nanomaterials which may help stimulate this area of research.

Plasma-assisted in-situ preparation of L-cystine functionalized silver nanoparticle: An intelligent multicolor nano-sensing of cadmium and paracetamol from environmental sample

L-cystine (L-cys) functionalized plasmonic silver nanomaterial (Ag NPs) was fabricated toward the selective and sensitive detection of paracetamol and cadmium. The prepared L-cys-Ag nanoparticles (NPs) were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD) and fourier transform infrared spectroscopy (FTIR) analyses. SEM imaging show that Ag NPs was decorated on the surface of L-cysteine 3D cubic nanosheet. L-cys-Ag NPs showed selective and sensitive detection towards paracetamol and cadmium. The interference study confirms that the presence of other metal ions didn't inhibit the detection of cadmium by L-cys-Ag NPs. The limit of detection of paracetamol and cadmium by L-cys-Ag NPs was calculated to be 1.2 and 2.82 nM respectively. In addition, the real sample detection of paracetamol on blood serum and urine, and cadmium on STP were performed and the recovery percentage was above 97%. Further, the real sample analysis was performed in tap and drinking water and the recovery percentage was more than 98%. The analytic logic gate on the multicolour detection of cadmium and paracetamol was performed for the semi-quantitative monitoring of paracetamol and cadmium by L-cys-Ag NPs. The developed L-cys-Ag NPs were found to be an effective tool for the monitoring of cadmium in environmental water bodies and paracetamol in blood and urine.

Sunlit photocatalytic degradation of organic pollutant by NiCr2O4/Bi2S3/Cr2S3 tracheid skeleton nanocomposite: Mechanism, pathway, reactive sites, genotoxicity and byproduct toxicity evaluation

In this study, 3D C₂S₃ (CS) and 2D Bi₂S₃ (BS) modified NiCr₂O₄ nanocomposite (NCO-BS-CS NCs) was prepared by sonochemical assisted co-precipitation method for the enhanced photocatalytic activity. Here, NCO-BS-CS NCs showed band gap energy of 2.23 eV and the PL intensity of NCO-BS-CS NCs was lower than NCO, BS, and CS NPs. Thus, the results indicate the fabricated NCO-BS-CS NCs enhance the charge segregation and lower in recombination rate. NCO-BS-CS NCs showed enhanced photodegradation of methyl orange (MO) (95%) and congo red (CR) (99.7%) respectively. The total organic compound (TOC) analysis shows the complete mineralization of about 91 and 98% for MO and CR respectively. Furthermore, the Fukui function was used for the prediction of reactive sites in the photodegradation pathway of MO and CR by NCs. ECOSAR program was done to determine the toxicity of the intermediate and the results conclude that the degraded product shows nontoxic to the environmental organism (fish, daphnia, and algae). Thus, the fabricated NCO-BS-CS NCs can be used for the remediation of toxic organic pollutants from the waste water by photocatalytic degradation.

Green synthesis of two-electron centre based ZnO/NiCo2S4 QDs-OVs using Punica granatum fruit peel extract for an exceptional visible light photocatalytic degradation of doxycycline and ciprofloxacin

Biosynthesis of nanomaterials using plant extract makes them attractive in the field of photocatalysis as they are environmental friendly. The current study focused on the biosynthesis of ZnO/NiCo₂S₄ QDs (NCs) using Punica granatum fruit peel extract as the reducing agent. The nanomaterials were characterized with XRD, FTIR, Raman, SEM, TEM, UV-vis DRS, BET, PL, EIS, and ESR analysis and were used for photocatalytic degradation of doxycycline (DOX) and ciprofloxacin (CIP). The bandgap of ZnO is 3.2 eV, and the decoration of NiCo₂S₄ QDs aids in narrowing the bandgap (2.8 eV), making the NCs visible light active. The fabricated NCs achieved 99 and 89% degradation of DOX and CIP respectively. The photocatalytic efficiency of ZnO/NiCo₂S₄ QDs was much higher compared to individual ZnO and NiCo₂S₄ QDs. The half-life period of DOX and CIP were evaluated to be 58 and 152 min respectively. The percentage of TOC removal in the photodegraded product of DOX and CIP was estimated to be 99 and 89% respectively, indicating the mineralization of the compounds. The enhanced photocatalytic efficiency of the NCs was attributed to the narrowed visible light active bandgap, synergistic charge transfer across the interface, and lower charge recombination. The intermediates formed during the photocatalytic degradation of DOX and CIP were analyzed using GC-MS/MS analysis, and the photodegradation pathway was elucidated. Also, the toxicity of the intermediates was computationally analyzed using ECOSAR software. The fabricated ZnO/NiCo₂S₄ QDs have excellent stability and reusability, confirmed by XRD and XPS analysis. The reusable efficiency of the NCs for the photocatalytic degradation of DOX and CIP were 98.93, and 99.4% respectively. Thus, the biologically fabricated NCs are shown to be an excellent photocatalyst and have wide applications in environmental remediation.

A prominent dual heterojunction framed CuWO4/Bi2WO6/MnS ternary NCs for para-chlorophenol degradation, Cr(VI) reduction & toxicity studies

In account of environmental remediation, an ideal photocatalyst was fabricated for the effective treatment of water systems. Herein, dual heterojunctions framed CuWO₄/Bi₂WO₆/MnS nanocomposite (NCs) was synthesized via simple co-precipitation method followed by ultra-sonicated assisted route. The prepared NCs were investigated its photocatalytic degradation performance using para-chlorophenol (4-CP) and reduction of chromium VI (Cr (VI)) under visible light irradiation. The photocatalyst were characterized by various analytical techniques including XRD, HR-TEM, XPS, UV-vis DRS, FE-SEM, EIS, PL, ESR, Raman and N₂ adsorption and desorption studies. The excellent photodegradation of 4-CP was observed within 180 min by the NCs. Similarly, the Cr (VI) reduction was about 97% within 140 min. The effect of pH and influence of different dosage of NCs and 4-CP on the photodegradation efficiency was investigated. The reusability and stability of the NCs was examined over 6 consecutive runs where the XRD and XPS confirm the structural stability of the prepared NCs. The scavenging experiment were carried out to elucidate the mechanism and the active species involved were O^2-• and OH• radicals. The TOC analysis affirmed the complete mineralization of the prepared NCs. The ecotoxicity analysis was carried out to determine the toxicity effect of intermediates using ECOSAR software and the end product toxicity was also evaluated against E. coli and S. epidermis. The end product toxicity study also confirmed that the degraded product was less toxic compared to parent compound. Further, the genotoxicity study was done to understand the environmental impact using allium cepa and results confirms that there are no causes of cytotoxicity & genotoxicity by the prepared NCs. Therefore, the prepared NCs can be economical, efficient with excellent photocatalytic performance and environment friendly.

Sunlit expeditious visible light-mediated photo-fenton degradation of ciprofloxacin by exfoliation of NiCo2O4 and Zn0·3Fe2·7O4 over g-C3N4 matrix: A brief insight on degradation mechanism, degraded product toxicity, and genotoxic evaluation in Allium cepa

Pharmaceutical pollutant in the environmental water bodies has become a major concern, which causes adverse effect to aquatic entities. This study provides an incisive insight on the photocatalytic degradation of ciprofloxacin (CIP) and the development of rationally engineered g-C3N4-NiCo2O4-Zn0.3Fe2·7O4 nanocomposite for boosted photocatalytic performance under visible light irradiation. The g-C3N4-NiCo2O4-Zn0.3Fe2·7O4 nanocomposite was synthesized via ultrasonication-assisted hydrothermal method. The characterization of the as-prepared material was evaluated by XPS, SEM, HR-TEM, PL, FT-IR, EIS, ESR, XRD, BET, and UV-Vis DRS techniques. Furthermore, the effect of catalytic dosage, drug dosage, and pH changes was explored, where g-C3N4-NiCo2O4-Zn0.3Fe2·7O4-10% unveiled excellent visible light photo-Fenton degradation of 92% for CIP at 140 min. The hydroxyl radicals (OH.) served as the predominant radical species on the photodegradation of CIP, which was confirmed by performing a radical scavenging test. Furthermore, the degradation efficiency was determined by six consecutive cycle tests, where the nanomaterial exhibited excellent stability with 98.5% reusable efficiency. The degradation of CIP was further scrutinized by GC-MS analysis, where the degraded intermediate products and the possible pathway were elucidated. The degraded product toxicity was determined by ECOSAR program, where the degraded products haven't exhibited any considerable toxic effects. In addition, the genotoxicity of the nanomaterial was determined by treating them with root tips of A. cepa, where it was found to be non-toxic. Here, the prepared g-C3N4-NiCo2O4-Zn0.3Fe2·7O4 nanocomposite (CNZ NCs) shows eco-friendly and excellent photo-Fenton activity for environmental applications.

Double Z-Scheme ZnCo2O4/MnO2/FeS2 photocatalyst with enhanced photodegradation of organic compound: Insights into mechanisms, kinetics, pathway and toxicity studies

The present work highlights the preparation of double Z-scheme ZnCo2O4/MnO2/FeS2 nanocomposite (NCs) and investigated its photocatalytic activity against methyl orange (MO) dye degradation under visible light. An array of techniques was carried out to characterize the nanoparticles (NPs) in order to evaluate their morphological, structural, optical, and photocatalytic properties using FE-SEM, TEM, XRD, N2 adsorption and desorption studies, PL, UV-visible spectrophotometer, XPS, Raman, and UV-vis DRS analysis. The degradation efficiency of NCs was tested along with different parameter studies such as different pH, NCs concentration, dye concentration, reusability and structural stability. The NCs exhibited complete photodegradation of MO dye under visible light within 80 min at pH 4. The structural and compositional stability of the prepared NCs over 6 consecutive cycles was tested via XRD and XPS analysis. The results of active species trapping experiments showed that O2-• and OH• are responsible for the degradation of MO dye. The TOC analysis showed 95% of mineralization by the prepared NCs. The MO dye degradation pathway was determined using GC-MS/MS analysis and drafted all the intermediates involved. End product toxicity via seed germination and intermediate toxicity study using ECOSAR software results in less toxicity of end product compared to parent compound. Finally, the genotoxicity of the prepared NCs was evaluated using Allium cepa and showed its no causes of cytotoxicity & genotoxicity by the prepared NCs. ZnCo2O4/MnO2/FeS2 NCs exhibited its high photocatalytic activity and the toxicity studies confirms that there is no cause of any environmental impact.

Robust visible light active CoNiO2-BiFeO3-NiS ternary nanocomposite for photo-fenton degradation of rhodamine B and methyl orange: Kinetics, degradation pathway and toxicity assessment

Sustainable wastewater treatment is crucial to remediate the water pollutants through the development of highly efficient, low-cost and separation free photocatalyst. The aim of this study is to construct a novel CoNiO₂-BiFeO₃-NiS ternary nanocomposite (NCs) for the efficient degradation of organic pollutants by utilising visible light. The NCs was characterized by various physiochemical techniques, including HR-TEM, SEM, XPS, FT-IR, ESR, EIS, PL, UV-visible DRS, and N₂ adsorption and desorption analysis. The photocatalyst exhibits extraordinary degradation efficiency towards MO (99.8%) and RhB (97.8%). The intermediates were determined using GC-MS analysis and the degradation pathway was elucidated. The complete mineralization was further confirmed by TOC analysis. The CoNiO₂-BiFeO₃-NiS ternary NCs have shown excellent photostability, structural stability and reusability even after six cycles and it is confirmed by XRD and XPS analysis. The kinetic study reveals that the photodegradation of the dyes follows first order reaction. The influence of different pH, dye concentrations and NCs dosages were investigated. The intermediate toxicity was predicted by computational stimulation using ECOSAR software. The NCs shows promising potential for ecological safety which demonstrates its practical application in the treatment of waste water pollutants in large scale.

Photodegradation of 5-flurouracil, carvedilol, para-chlorophenol and methimazole with 3D MnWO4 nanoflower modified Ag2WO4 nanorods: A non-genotoxic nanomaterial for water treatment

The present study focused on the photocatalytic degradation of 5-Flurouracil (FU), carvedilol (Car), para-chlorophenol (PCP) and methimazole (Met) under visible light irradiation by MnWO₄/Ag₂WO₄ (MWO/AWO) nanohybrid. Here, MWO/AWO nanohybrid was characterized by XRD, TEM, EDS, XPS, ESR, EIS, BET and DRS. The band gap energy of the MWO/AWO nanohybrid was found to be 2.75 eV, which enables effective photocatalytic activity of nanohybrid under visible light. The photocatalytic degradation of various PhACs such as Fu, Car, PCP and Met was found to be 98.8, 100, 98 and 98.1% respectively. The degradation efficiency of the MWO/AWO nanohybrid on various PhACs was higher than the pure MWO and AWO nanoparticle. The effective formation of OH• and •O₂ by MWO/AWO nanohybrid played an important role in degradation of PhACs and it was determined by radical scavenging experiment. Further, the intermediates formed during the photocatalytic process were analyzed by GC-MS/MS to elucidate the photodegradation pathway and the results reveal the complete mineralization of the PhACs. The toxicity of the degraded product was performed against on Bacillus subtilis and Escherichia coli where it shows that the nanohybrid possesses high relative growth inhibition than AWO and MWO nanoparticles. In addition, the genotoxicity of the nanohybrid against Allium cepa was performed and it exhibited lower toxicity. The synthesized nanohybrid proves to be an excellent photocatalyst with good stability, reusability, eco-friendly, and cost-effective material for implementation in practical applications.

Designing novel MgFe2O4 coupled V2O5 nanorod for synergetic photodegradation of tetracycline with enhanced visible-light energy harvesting: Photoluminescence, kinetics, intrinsic mechanism and bactericidal effect

The present study focused on the enhancement of degradation of an important pharmaceutical pollutant, tetracycline with the help of nano photocatalyst under visible light irradiation. The study found that the synergetic effect of novel MgFe₂O₄-V₂O₅ enhanced the photocatalytic degradation of tetracycline. Here, the photocatalyst was synthesized by sonochemical technique. Scanning electron microscopy image indicates the coupling of MgFe₂O₄ nanocapsules on the surface of the V₂O₅ nanorod. The bandgap of MgFe₂O₄ (1.8 eV) and V₂O₅ (2.5 eV) was shifted to 2.32 eV in MgFe₂O₄-V₂O₅ to promote visible-light harvesting and it was depicted by the UV-visible DRS. XPS was used to identify the presence of chemical states with the existence of Mg 1s, Fe 2p, V 2p, and O 1s. The electrochemical impedance spectroscopy and photoluminescence spectra indicate the better separation of charge carriers owing to the formation of type II heterojunction formation. The tetracycline (25 mg/L) was degraded with MgFe₂O₄-V₂O₅ (150 mg/L) that exhibited 3.3 and 5 folds enhanced rates than its counterparts (MgFe₂O₄ and V₂O₅) owing to synergism. The possible intermediate formation and degradation pathway was determined based on GC/MS analysis. TOC analysis of end products indicated maximum mineralization of tetracycline. The MgFe₂O₄-V₂O₅ showed excellent recycling ability and reusability. The key photo-degradation of tetracycline was occurred by the generation of hydroxyl radicals. The MgFe₂O₄-V₂O₅ exhibited high antibacterial activity that ensures the dual functionality of the prepared nanocomposites (NCs). Therefore, the present study displays MgFe₂O₄ decorated V₂O₅ nanorod as an ideal candidate for environmental remediation.

Designing Z-scheme AgIO4 nanorod embedded with Bi2S3 nanoflakes for expeditious visible light photodegradation of congo red and rhodamine B

The present study describes the enhanced photodegradation of organic pollutant dyes, congo red (CR) and rhodamine B (RhB) dyes under visible light irradiation. AgIO₄ nanorods decorated on Bi₂S₃ nanoflakes in various proportions were synthesized via sono-chemical route wherein the deposition of varying amounts of AgIO₄ on Bi₂S₃ plays a pivotal role in improving the photodegradation ability. The characterization of the as-synthesized nanohybrids was assessed by XRD, UV-vis DRS, PL, EIS, ESR, FT-IR, XPS, HR-TEM, FE-SEM, N₂ adsorption and desorption techniques. The effect of initial CR and RhB dye concentration, reaction pH and usage of nanohybrid concentration were investigated where 30%-AgIO₄/Bi₂S₃ exhibited excellent visible light photodegradation of 95.58% for CR and 96.11% for RhB dyes at 140 min and 100 min respectively. The superoxide (•O^2-) and hydroxyl radicals (•OH) played predominant role in the photodegradation of CR and RhB which is experimentally confirmed by radical trapping experiments. Also, the photocatalysts exhibited good photo stability and excellent reusability. The TOC analysis confirmed the complete mineralization of CR and RhB dyes by the nanohybrid and the formation of possible intermediate and degradation pathway was delineated based on GC/MS analysis. The outstanding photodegradation performance were ascribed to the Z-scheme charge transfer path, which effectively promotes the separation and transfer of e^-/h⁺ pairs, resulting in a strong redox activity of the accumulated charge to decompose organic dyes during the degradation reaction. The study suggested that the nanohybrid can be utilized for the removal of organic pollutants from the contaminated water bodies.

Self-assembling of 3D layered flower architecture of BiOI modified MgCr2O4 nanosphere for wider spectrum visible-light photocatalytic degradation of rhodamine B and malachite green: Mechanism, pathway, reactive sites and toxicity prediction

In this study, 3D BiOI nanoparticle (BOI NPs) modified MgCr₂O₄ nanoparticle (MCO NPs) was fabricated by simple sonochemical and coprecipitation method for the enhanced photocatalytic activity. The morphological structure of the MgCr₂O₄-BiOI nanocomposite (MCO-BOI NCs) was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (DRS), electron impedance spectroscopy (EIS) and photo luminescence (PL). The lower in the PL intensity and small arc in EIS for NCs shows the effective charge separation and lower in rate of recombination of charge carriers in NCs than the pure MCO and BOI NPs. The degradation efficiency of Rhodamine B (RhB) and malachite green (MG) by MCO-BOI NCs was found to be 99.5% and 98.2% receptivity. In addition, the photocatalytic degradation of RhB and MG was studied under various environmental parameters (different pH, varying the concentration of NCs and dyes) and response surface (RSM) plot was performed. The complete mineralization of RhB and MG by MCO-BOI NCs was determined by TOC. In addition, the photocatalytic degradation pathway was elucidated based on GC-MS results and Fukui function. In addition, the toxicity of intermediate formed during the degradation of RhB and MG was predicted by ECOSAR. The present work highlights the application of MCO-BOI NCs in environmental remediation for toxic pollutant removal.

Synthesis and application of CdS nanoparticles-decorated core-shell Ag@Ni nanohybrids for visible-light spectrophotometric assay of sulfide in aqueous sample

Novel Ag@Ni nanosphere decorated with CdS NPs (Ag@Ni-CdS NCs) was synthesized by one step chemical synthesis method. The fabricated NCs were characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), fourier transfer infra-red spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), zeta sizer and particle size analyzer. TEM and XRD confirmed the Ag in core and Ni in shell for the effective formation of Ag@Ni core shell nanosphere. EDAX and XPS spectra of NCs confirms the formation of Ag@Ni-CdS NCs. Zeta potential and particle size of the NCs was found to be 29.5 ± 1.5 mV and 24 ± 1 nm respectively. The complete loss in the peak intensity of Ag@Ni-CdS NCs (localized surface plasmon resonance (LSPR)) at ∼410 nm in presence of S^2- ions was observed which indicates its selective detection towards S^2- ions. The sulfide ion sensing by Ag@Ni-CdS NCs was due to the successive oxidation of Ag results in the formulation of Ag²⁺ ions in the system, which causes the diminishing of LSPR band of NCs. The limit of detection (LOD) of S^2- ions by Ag@Ni-CdS NCs was calculated to be of 2.66 nM. The combination of CdS NPs with core-shell Ag@Ni nanosphere guides a promising strategy for S^2- ions detection from environmental polluted samples.

CuO loaded ZnS nanoflower entrapped on PVA-chitosan matrix for boosted visible light photocatalysis for tetracycline degradation and anti-bacterial application

Novel photocatalyst CuO loaded ZnS nanoflower supported on carbon frame work PVA/Chitosan was synthesized by co-precipitation and ultrasonic assisted method. The co-existence of ZnS and CuO and its crystallinity in nanohybrid was verified by XRD, SAED and HR-TEM analysis. The availability of defects in ZnS was identified by EPR. FTIR and TGA verified the presence of PVA and Chitosan. Defects mediated ZnS-CuO/PVA/chitosan heterojunction promote synergistic charge separation with type II interface. Zn-vacancy facilitates two-photon excitation that improves visible-light harvesting. The photocatalytic activity of ZnS-CuO/PVA/Chitosan was 94.7% which is higher when compared to ZnS (40%) and CuO (60%). The photocatalytic mechanism was elucidated using scavenger test and both ·O₂^- and ·OH were found to play key role in tetracycline degradation. In addition, ZnS-CuO/PVA/Chitosan demonstrated efficient anti-microbial effect against the both gram strains on comparing with individual ZnS and CuO. Thus, the multifunctional ZnS-CuO/PVA/Chitosan is promising for the photocatalytic degradation of tetracycline and as an antimicrobial agent.

Recent advances in degradation of organic pollutant in aqueous solutions using bismuth based photocatalysts: A review

Today, a major concern associated with the environment is the water pollution occurred due to the introduction of variety of persistent organic pollutants and residual dyes from different sources (e.g., dye and dye intermediates industries, paper and pulp industries, textile industries, tannery and craft bleaching industries, pharmaceutical industries, etc.) into our natural water resources. Recently, advanced oxidation processes (AOPs) by photocatalyst have garnered great attention as a new frontier promising eco-friendly and sustainable wastewater treatment technology. Utilization of the photocatalytic technology efficiently is significant for cleaner environment. Bismuth based photocatalyst have aroused widespread attention as a visible light responsive photocatalyst for waste water treatment due to their non-toxicity, low cost, modifiable morphology, and outstanding optical and chemical properties. In this review, we have dealt with the research progress on bismuth-based photocatalysts for waste water treatment. However, it seems to give limitation over pristine photocatalysts such as slow migration of charge carriers, charge carrier recombination, low visible light absorption, etc., Various bismuth based photocatalyst and its modifications via doping, heterojunction, Z-scheme etc., are discussed in detail. Further, the strategies adopted to improve the photocatalytic activity of bismuth based photocatalyst to improve the waste water treatment (mostly drugs and dyes) are critically reviewed. Also, we have discussed the bacterial inactivation by bismuth based photocatalyst. Finally, the challenges and future aspects against bismuth based photocatalyst are explored for further research.

Recent developments in architecturing the g-C3N4 based nanostructured photocatalysts: Synthesis, modifications and applications in water treatment

Water pollution is becoming an inevitable problem in today's world. Tons and tons of wastewater with hazardous pollutants are getting discharged into the clean water bodies every day. In this regard, photocatalytic environmental remediation using nanotechnology such as the use of organic, metal and non-metal based semiconductor photocatalysts for photodegradation of pollutants has gained enormous attention in the past few decades. This review is focused particularly on graphitic carbon nitride (g-C₃N₄) which is a cheap, metal-free, polymeric photoactive compound and it is used as a potential photocatalyst in wastewater treatment. Though, pristine g-C₃N₄ is a good photocatalyst, it has certain drawbacks such as poor visible light absorption capacity, quicker recombination of photoelectrons and holes, delayed mass and charge transfer, etc. As a result, the pristine g-C₃N₄ catalyst is modified into novel 0D, 1D, 2D and 3D morphologies such as nano-quantum dots, nanorods, nanotubes, nanowires, nanosheets, nanoflakes, nanospheres, nanoshells, etc. It was also tailored into novel composites along with various compounds through doping, metal deposition, heterojunction formation, etc., to enhance the photocatalytic property of pure g-C₃N₄. The modified catalysts showed promising photocatalytic performance such as degradation of majority of pollutants in the environment. It also showed excellent results in the removal or reduction of heavy metals. This review provides a detailed record of g-C₃N₄ and its diverse photocatalytic applications in the past years and it provides knowledge for the development of such similar novel compounds in the future.

Ag0 decorated Cr2S3 NPs embedded on PVP matrix: A colorimetric probe for selective and rapid detection of sulphide ions from environmental samples

Globally, the environmental pollution is one of the major issues causing toxicity towards human and aquatic life. We have developed a facile and innovative sensing approach for detection of sulphide ions (S^2-) present in the aqueous media using Ag⁰ decorated Cr₂S₃ NPs embedded on PVP matrix (Ag/Cr₂S₃-PVP). Based on the SPR phenomena, the detection of S^2- ions was established. The nanohybrid was characterized using various techniques such as UV-vis spectrophotometer, High-Resolution Transmission Electron Microscopy (HR-TEM), Thermal Gravimetric Analysis (TGA), X-ray diffraction analysis(XRD), Energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The yellowish colour of Ag/Cr₂S₃-PVP nanohybrid turned to brown colour in presence of S^2- ions. The selectivity and sensitivity of the prepared probe was studied against the other interfering metal ions. In addition, the effect of different concentration of S^2- ions in the nanohybrid solution was investigated and the Limit of detection (LOD) was found to be 6.6 nM. The good linearity was found over the range of 10 nM to 100 μM with R² value of 0.981. The paper strip based probe was developed for rapid onsite monitoring of S^2- ions. The proposed method is found to be cost-effective, rapid, and simple. We have validated the practical applicability of the prepared probe for determining the concentration of S^2- ions in real water samples.

Pharmaceuticals removal by synergistic adsorption and S-scheme photocatalysis using nano-CeO2-coupled Fe3O4 on a CTAB matrix and investigation of the nanocomposite's antibacterial and antibiofilm activities: intrinsic degradation mechanism

S-Scheme photocatalytic mechanism of a fabricated nano-heterojunction.

In situ construction of ZnFe2O4 nanospheres on CoO nanosheets for durable photodegradation of organics: kinetics and mechanistic insights

The development of a low-cost, efficient and sustainable technology is considered to be of paramount for the efficient degradation of toxic pollutants.

Subsurface and solid solution-type defect engineering in CoCr2O4-Bi2WO4-NiS2 nanocomposite for visible light degradation of doxycycline and chromium removal and its genotoxic evaluation in Allium cepa

In the present work, ternary CoCr2O4-Bi2WO4-NiS2nanocomposite (CCO-BWO-NS NCs), a semiconductor photocatalyst prepared for the effective minerization of doxycycline and photocatalytic removal of Cr(VI). Here, the modification of BiO-WO4-BiO (BWO) as...

A novel SPR based Fe@Ag core-shell nanosphere entrapped on starch matrix an optical probe for sensing of mercury(II) ion: A nanomolar detection, wide pH range and real water sample application

Recent trends in nanotechnology paved a way for the development of detection systems for heavy metals, toxins and environmental pollutants. The present study focused on Hg²⁺ detection by a core shell Fe@Ag-starch nanosphere phenylalanine conjugate. The characterization of core shell Fe@Ag-starch nanosphere was performed by using TEM, zetasizer, particlesize analyzer, UV-visible absorption spectrophotometer, EDAX, FTIR and TGA. The NPs showed λmax at 408 nm. The effective diameter of synthesized nanosphere was 37 ± 2 nm and it possessed the surfaces charge of -36.12 ± 2.5 mV. The Fe@Ag-starch-phenylalanine conjugate reacted with Hg²⁺, the yellow colour of the nanosphere phenylalanine conjugate became colourless. The real water sample was collected and the amount of Hg²⁺ was calculated by using the prepared nanosphere. The detection of Hg²⁺ at different conditions including various saline concentrations, temperature and pH were also studied and the detection was found to be effective at 40 °C, pH 5 and 0.1% of saline concentration. The LOD of Hg²⁺ ions by Fe@Ag-starch nanosphere were calculated to be 1.84 nM. The influence of other metal ions present in the analyte did not show any interference on Hg²⁺ detection. In addition, the photocatalytic and antibacterial activities of Fe@Ag-starch nanosphere were also studied. The study confirmed that the core shell nanosphere can also be used for environmental cleanup and disinfection.

The toxicity analysis of PVP, PVA and PEG surface functionalized ZnO nanoparticles on embryonic as well as adult Danio rerio

Globally, the production of zinc oxide nanoparticles (ZnO NPs) increased due to its wide applications including cosmetics, paints etc., and gets accumulated in the environment during their production, use or end-of-life. The toxic effects of the NPs vary with the presence of various surface modification agents. In the current report, toxic effect of bare and capped ZnO NPs with polymeric surface modifying agent including polyvinyl alcohol (PVA), polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) is studied against adult as well as embryonic zebra fish. The surface capped NPs showed great variation in toxicity levels. It was observed that ZnO-PVA showed highly reduced toxic effects relative to ZnO-PEG and ZnO-PVP. Further, various environmental agents including humic acid can also have an impact on NPs toxicity. ZnO particles showed increased toxic effect in humic acid presence. The uptake of ZnO particles by D. rerio was high in the order of PVP-, PEG- and PVA- followed by bare-ZnO. The current investigation found that ZnO NPs dissolution and uptake are the major factors which cause the toxicity against adult as well as embryonic zebra fishes respectively.

Chitosan capped Ag/NiS nanocomposites: A novel colorimetric probe for detection of L-cysteine at nanomolar level and its anti-microbial activity

L-Cysteine (L-cys) plays very crucial role in biological systems. The study reports the colorimetric detection of L-cys at nanomolar level using chitosan capped Ag decorated NiS nanocomposite (chit-Ag/NiS NCs).The chemical reduction and co-precipitation methods were adopted to prepare chit-Ag/NiS NCs. The fabricated NCs was characterized by X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR), FT-Raman, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The chit-Ag/NiS NCs particularly detect L-cys even in other amino acids presence. The chit-Ag/NiS NCs showed the surface charge of -26 ± 39.9 mV. The detection of L-cys was indicated by disappearance of yellowish-brown color of Chit-Ag/NiS NCs to colorless. A good linear correlation was found between absorbance vs logarithmic concentration of L-cys (1 μM to 1 nM) with R² value of 0.99. The chit-Ag/NiS NCs impregnated cotton swabs was prepared for real time detection of L-cys and the prepared probe was found to be highly selective and specific. The effect of pH, temperature and salinity influencing the L-cys detection was studied. Also, the antimicrobial activity of Chit-Ag/NiS NCs was investigated against gram negative (E. coli) and gram positive (B. subtilis) bacteria.

Global Guidelines in Dermatology Mapping Project (GUIDEMAP): a scoping review of dermatology clinical practice guidelines

BACKGROUND

Clinical practice guidelines (CPGs) play a critical role in standardizing and improving treatment outcomes based on the available evidence. It is unclear how many CPGs are available globally to assist clinicians in the management of patients with skin disease.

OBJECTIVES

To search for and identify CPGs for dermatological conditions with the highest burden globally.

METHODS

We adapted a list of 12 dermatological conditions with the highest burden from the Global Burden of Disease (GBD) study 2019. A systematic literature search was done to identify CPGs published between October 2014 to October 2019. The scoping review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework.

RESULTS

A total of 226 CPGs were included. Melanoma had the greatest representation in the CPGs, followed by dermatitis and psoriasis. Skin cancers had a relatively high CPG representation but with lower GBD disease burden ranking. There was an uneven distribution by geographical region, with resource-poor settings being under-represented. The skin disease categories of the CPGs correlated weakly with the GBD disability-adjusted life-years metrics. Eighty-nine CPGs did not have funding disclosures and 34 CPGs were behind a paywall.

CONCLUSIONS

The global production of dermatology CPGs showed wide variation in geographical representation, article accessibility and reporting of funding. The number of skin disease CPGs were not commensurate with its disease burden. Future work will critically appraise the methodology and quality of dermatology CPGs and lead to the production of an accessible online resource summarizing these findings.

Determinants of Pre-Hospital Delay after Myocardial Infarction in Bangladesh: A Rural Center Experience

Determinants of pre-hospital delay after myocardial infarction, strictly among South-Asian rural community, till now is largely unknown. And Bangladesh is not an exception. It is a fact that though around two third of its population still live in villages, we do not know what factors are having influence on such delay. To find out these primers of time consumption before seeking medical help, this is a picture of a medical college hospital situated in a rural precinct. This cross-sectional analytical study was conducted among 98 patients came with Myocardial Infarction (MI) who had met inclusion and exclusion criteria from July 2019 and December 2019. Both STEMI & NSTEMI patients were selected as they have similar attributes. Data was collected in the coronary care unit using a preformed questionnaire. Among 98 MI patients, where 16 female and 82 male patients had average age 53±12 years. Average income rural community was around 100 USD. Almost 50% of sample were illiterate or below 5th grade. On average 6.6 hours (95% CI: 3.5-12.3) were required to reach CCU after symptom onset, whereas distance to first medical contact (FMC) was about 10.2 Km (95% CI: 6.4-16.2). Median distance to nearest PCI-capable hospital was 140 Km (IQR- 20 Km). Only 28% of patients could reach hospital within 2 hours, where 85% had onset of symptom while they were at home. Tertiary level medical college (74.5%) followed by Upazilla (Sub-urban) government health complex (22.4%) were frequent site of FMC. Principle mode of transport to hospital was CNG-three-wheeler (75% of cases). Logistic regression analysis showed only low literacy was as significant predictor about more than 2 hours pre-hospital delay (OR=2.58; p=0.043). Other factors such as low income (OR=2.51; p=0.126), diabetes mellitus (OR=2.99; p=0.059), female sex (OR=1.56; p=0.753), house wife (OR=1.88; p=0.547), previous MI (OR=1.52; p=1.000), symptom ignorance (OR=2.14; p=0.455) increases pre-hospital delay and distance to FMC <10 Km (OR=0.44; p=0.079) no significant prediction of pre-hospital delay after myocardial infarction. As rural community has less access to education low literacy has a significant impact on pre-hospital delay after myocardial infarction. So measures should be taken in rural areas through patient education and social awareness program regarding MI symptom and danger of delayed medical attention.