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This study presents the synthesis of CeO2-TiO2 nanocomposite and its potential application for the visible light-driven photocatalytic degradation of model crystal violet dye as well as real industrial waste water. The ceria-titania (CeO2-TiO2) nanocomposite material was synthesised using facile hydrothermal route without the assistance of any template molecule. As-prepared composite was characterised by SEM, TEM, HRTEM, XRD, XPS for surface features, morphological and crystalline characters. The formed nanostructures were determined to possess crystal-like geometrical shape and average size less than 100 nm. The as-synthesised nanocomposite was further investigated for their heterogeneous photocatalytic potential against the oxidative degradation of CV dye taken as model pollutant. The photo-catalytic performance of the as-synthesised material was evaluated both under ultra-violet as well as visible light. Best photocatalytic performance was achieved under visible light with complete degradation (100%) exhibited within 60 min of irradiation time. The kinetics of the photocatalytic process were also considered and the reaction rate constant for CeO2-TiO2 nanocomposite was determined to be 0.0125 and 0.0662 min−1 for ultra-violet and visible region, respectively. In addition, the as-synthesised nanocomposite demonstrated promising results when considered for the photo-catalytic degradation of coloured industrial waste water collected from local textile industry situated in Faisalabad region of Pakistan. Enhanced photo-catalytic performance of CeO2-TiO2 nanocomposite was proposed owing to heterostructure formation leading to reduced electron-hole recombination. [ABSTRACT FROM AUTHOR]

Since the emergence of zero waste concept, efficient waste recycling system and recovery of energy from the waste materials become challenging tasks globally. Municipal solid waste (MSW) is considered as one of a potential sources of energy. In the present study, bio-compactable iron oxide (Fe3O4) nanoparticles (NPs) were synthesized by hydrothermal method. These NPs were characterized by using atomic force microscopy (AFM), energy dispersive x-ray (EDX), and scanning electron microscopy (SEM) for size determination and surface morphology. The organic fraction of MSW (OFMSW) such as food waste (FW) was utilized as a substrate in this study. The anaerobic digestion of OFMSW in batch test was carried out under mesophilic temperature (37 ± 0.5°C). Four different concentrations of Fe3O4NPs i.e 50mg/L, 75mg/L, 100mg/L, and 125mg/L were added in each batch test. It was observered that 75mg/L yielded maximum CH4and followed by 50mg/L. [ABSTRACT FROM PUBLISHER]

This study describes the development of an electrochemical sensor system for the determination of bisphenol A using tannic acid functionalized CuO nanoglobules. The utilized tannic acid acted simultaneously as both bio-compatible template and functionalizing agent for the as-synthesised CuO nanostructures. The excellent synergy of high surface area and favorable interactions between the moieties of tannic acid and bisphenol A molecules enabled sensitive electrochemical oxidation of bisphenol A within wide detection window (0.1–5.5 µM) and limit of detection estimated to be 0.01 µM. Moreover, the sensor exhibited satisfactory stability and strong anti-interference capability when evaluated against common interferents molecules such as phenol, hydroquinone, and 4-nitrophenol. [ABSTRACT FROM PUBLISHER]

The study describes the application of oxidation resistant copper nanostructures as an efficient heterogeneous catalyst for the treatment of organic dye containing waste waters. Copper nanostructures were synthesized in an aqueous environment using modified surfactant assisted chemical reduction route. The synthesized nanostructures have been characterized by UV-Vis, Fourier transform infrared spectroscopy FTIR spectroscopy, Atomic force microscopy (AFM), Scanning Electron Microscopy (SEM), and X-ray diffractometry (XRD). These surfactant capped Cu nanostructures have been used as a heterogeneous catalyst for the comparative reductive degradation of methyl orange (MO) in the presence of sodium borohydride (NaBH4) used as a potential reductant. Copper nanoparticles (Cu NPs) were found to be more efficient compared to copper nanorods (Cu NRds) with the degradation reaction obeying pseudofirst order reaction kinetics. Shape dependent catalytic efficiency was further evaluated from activation energy (EA) of reductive degradation reaction. The more efficient Cu NPs were further employed for reductive degradation of real waste water samples containing dyes collected from the drain of different local textile industries situated in Hyderabad region, Pakistan. [ABSTRACT FROM AUTHOR]

The present study reports the synthesis of novel hedgehog-like NiO nanostructures via hydrothermal method using l -cysteine as a structure directing agent. The as-synthesized hedgehog-like NiO nanostructures were characterized by scanning electron microscopy (SEM), X-ray photoelectron microscopy (XPS) X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques for morphological, compositional and structural studies respectively. The prepared NiO nanostructures were applied for the design and engineering of non-enzymatic glucose sensor in the alkaline medium. The electrode material for glucose sensing based on the hedgehog-like NiO nanostructures demonstrated extremely high electrochemical response with high sensitivity (1052.8 μA mM −1 cm −2 ), low detection limit (LOD) (1.2 μM), high selectivity, wide linear range (0.1–5.0 μM) ( R 2 = 0.9982) and the outstanding reproducibility. A plausible growth mechanism has been proposed to explain the formation process of the hedgehog-like NiO nanostructures. The excellent sensing performance can be attributed to the unique surface architectures, which enhanced the electron transfer rate and the molecular approach during the electrochemical sensing of glucose. Furthermore, the sensor showed excellent performance for the quantification of glucose in real blood sera reflecting universal nature of the presented glucose sensor. [ABSTRACT FROM AUTHOR]

The aim of this study was to reduce the highly toxic hexavalent chromium Cr(VI) into less toxic chromium Cr(III) species by using nickel nanoparticles (Ni NPs) as catalysts in order to provide safety to the aqueous environment. In the first phase Ni NPs were synthesized in ethylene glycol and capped with 1-cysteine by a modified microwave irradiation method using NaOH as the accelerator. The formed Ni NPs were characterized by various techniques such as UV-Visible spectroscopy, Fourier Transform Infra-red (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). In the second phase the formed Ni NPs were immobilized on glass surfaces and employed as catalyst for the reduction of Cr(VI) ions. According to observations, 99% reduction of Cr(VI) ions was achieved in the presence of 0.5 mg of Ni NPs catalyst in just five minutes as compared to nickel powder that showed only 16% reduction in 15 minutes. The study has a great impact on the aqueous pollution control of Cr(VI) especially caused by the discharge of waste water from several industries utilizing Cr(VI) containing salt as one of the essential gradients. [ABSTRACT FROM AUTHOR]

Procalcitonin (PCT) protein has recently been identified as a clinical marker for bacterial infections based on its better sepsis sensitivity. Thus, an increased level of PCT could be linked with disease diagnosis and therapeutics. In this study, we describe the construction of the photoelectrochemical (PEC) PCT immunosensing platform based on it situ grown photo-active CuWO4 nanospheres over reduced graphene oxide layers (CuWO4@rGO). The in situ growth strategy enabled the formation of small nanospheres (diameter of 200 nm), primarily composed of tiny self-assembled CuWO4 nanoparticles (2–5 nm). The synergic coupling of CuWO4 with rGO layers constructed an excellent photo-active heterojunction for photoelectrochemical (PEC) sensing. The platform was then considered for electrocatalytic (EC) mechanism-based detection of PCT, where inhibition of the photocatalytic oxidation signal of ascorbic acid (AA), subsequent to the antibody–antigen interaction, was recorded as the primary signal response. This inhibition detection approach enabled sensitive detection of PCT in a concentration range of 10 pg·mL−1 to 50 ng.mL−1 with signal sensitivity achievable up to 0.15 pg·mL−1. The proposed PEC hybrid (CuWO4@rGO) could further be engineered to detect other clinically important species. [ABSTRACT FROM AUTHOR]

In this report, we firstly synthesized nitro calix [4] resorcinarene compound (referred as KA30) and characterized it though proton ( 1 H) nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and Fourier Transform Infra-red (FTIR) spectroscopy. KA30 was applied as functionalizing agent for the formation of silver nanoparticles (KA30-AgNPs). These NPs were confirmed as highly selective and extremely sensitive colorimetric sensor for ultra-low level detection of emamectin (EMA) as a novel report. Significant aspect of the sensor is its unique detection range between 0.0005 and 29.5 μM via color change from yellow to colorless with hypochromic-bathochromic shift exhibiting limit of detection (LOD) and limit of quantification (LOQ) as 0.12 nM and 0.4 nM respectively. The sensor was applied to colorimetrically and optically detect EMA in real samples of serum, urine and food. The sensor was further allied with smartphone for real-time, and on-site detection of EMA and results were validated through UPLC., Competing Interests: Declaration of competing interest The authors of this manuscript declare no competing interest that can affect the work the reported work., (Copyright © 2023. Published by Elsevier Ltd.)

Electrochemical immunosensors, surpassing conventional diagnostics, exhibit significant potential for cancer biomarker detection. However, achieving a delicate balance between signal sensitivity and operational stability, especially at the heterostructure interface, is crucial for practical immunosensors. Herein, porous carbon (PC) integration with Ti 3 C 2 T x -MXene (MX) and gold nanoparticles (Au NPs) constructs a versatile immunosensing platform for detecting extracellular matrix protein-1 (ECM1), a breast cancer-associated biomarker. The inclusion of PC provided robust structural support, enhancing electrolytic diffusion with an expansive surface area while synergistically facilitating charge transfer with Ti 3 C 2 T x . The biosensor optimized with 1.0 mg PC demonstrates a robust electrochemical redox response to the surface-bound thionine (th) redox probe, utilizing an inhibition-based strategy for ECM1 detection. The robust antibody-antigen interactions across the PC-integrated Ti 3 C 2 T x -Au NPs platform (MX-Au-C-1) enabled robust ECM1 detection within 0.1-7.5 nM, with a low limit of detection (LOD) of 0.012 nM. The constructed biosensor shows improved operational stability with a 98.6 % current retention over 1 h, surpassing MXene-integrated (MX-Au) and pristine Au NPs (63.2 % and 44.3 %, respectively) electrodes. Moreover, the successful adaptation of the artificial neural network (ANN) model for predictive analysis of the generated DPV data further validates the accuracy of the biosensor, promising its future application in AI-powered remote health monitoring., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Selcan Karakus reports administrative support and writing assistance were provided by Istanbul University-Cerrahpasa. No relationship or activity. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Selective oxidation of biomass-based molecules to high-value chemicals in conjunction with hydrogen evolution reaction (HER) is an innovative photocatalysis strategy. The key challenge is to design bifunctional photocatalysts with suitable band structures, which can achieve highly efficient generation of high-value chemicals and hydrogen. Herein, NiS/Cd 0.6 Zn 0.4 S Schottky junction bifunctional catalysts are constructed for sunlight-driven catalytic vanillyl alcohol (VAL) selective oxidation towards vanillin (VN) coupling HER. At optimal conditions, the 8% NiS/Cd 0.6 Zn 0.4 S photocatalyst achieves high activity of VN production (3.75 mmol g -1 h -1 ) and HER (3.84 mmol g -1 h -1 ). It also exhibits remarkable VAL conversion (66.9%), VN yield (52.1%), and selectivity (77.8%). The photocatalytic oxidation of VAL proceeds a carbon-centered radical mechanism via the cleavage of α C-H bond. Experimental results and theoretical calculations show that NiS with metallic properties enhances the electron transfer capability. Importantly, a Ni-S-Cd "electron bridge" formed at the interface of NiS/Cd 0.6 Zn 0.4 S further improves the separation/transfer of electrone/h + pairs and also furnishes HER active sites due to its smaller the |ΔG H* | value, thereby resulting in a remarkably HER activity. This work sheds new light on the selective catalytic oxidation VAL to VN coupling HER, with a new pathway towards achieving its efficient HER efficiency., (© 2023 Wiley-VCH GmbH.)

Bismuth-based materials are regarded as promising anode materials for potassium ion batteries (PIBs) due to their high theoretical capacity and low working potential. However, the large volume expansion and sluggish kinetics during cycling are major limitations to their practical application. Herein, a unique Bi/Bi 2 O 3 -C heterostructure was designed through a simple Bi-metal-organic framework (MOF) modulation-pyrolysis process. X-ray photoelectron spectroscopy, transmission electron microscopy, and X-ray diffraction revealed that the Bi and Bi 2 O 3 can form hetero-particles, which were uniformly embedded in a plate-like carbon skeleton, constructing a Bi/Bi 2 O 3 -C heterostructure. The carbon skeleton and the formation of numerous hetero-interfaces between Bi, Bi 2 O 3 , and carbon can effectively promote the interfacial charge transfer, shorten the K + diffusion pathway, and alleviate the volume expansion of Bi/Bi 2 O 3 during potassiation. Consequently, the Bi/Bi 2 O 3 -C heterostructure exhibited a high reversible capacity of 426.0 mAh g -1 at 50 mA g -1 , excellent cycle performance of 251.8 mAh g -1 after 350 cycles with a capacity retention of 76.6 %, and superior rate capability of 82.7 mAh g -1 at 1 A g -1 , demonstrating its promising potential for the application of PIBs anode., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Interfacial charge-carrier recombination is a bottle-neck issue restricting photoelectrochemical biosensors advancement in the wearable clinical electronics. In this study, we propose a simple approach to construct a highly efficient photoactive heterojunction capable of functioning as an active substrate in PEC biosensing of CD44 proteins. Taking the advantage of high photocatalytic activity of BiVO 4 , and biocompatible yet conductive 2D-Ti 3 C 2 T x nanosheets, a workable heterojunction was constructed between in-situ formed TiO 2 from the partially oxidized Ti 3 C 2 T x and lysine functionalized BiVO 4 (TiO 2 /MX-BiVO 4 ). The interfacial arrangement was ideal for promoting fast charge transfer from photo-excited BiVO 4 and TiO 2 to Ti 3 C 2 T x , constructing an energy level-cascade that permits minimal charge-carrier recombination besides robust photocatalytic redox activity. The PEC biosensor relies on the ligand-protein interaction, where hyaluronic acid was directly immobilized over TiO 2 /MX-BiVO 4 based on the interactions between carboxyl of lysine and amino moieties of hyaluronic acid. The PEC biosensor response depends on the inhibition in the measured photo-oxidation current of mediator species, i.e., ascorbic acid after the addition of CD44 proteins. The superior photo-activity, and robust heterojunction arrangement, produced a sensitive signal capable of recognizing CD44 in the wide concentration window of 2.2 × 10 -4  ng mL -1 to 3.2 ng mL -1 with a low-detection limit of 1.4 × 10 -2  pg mL -1 . The strong interaction between lysine functionalized BiVO 4 and hyaluronic acid enabled biosensor to exhibit robust antifouling characteristics towards similar proteins such as PSA and NSE. The quantification of CD44 protein from real-blood serum samples further confirmed the biosensor's reliability for clinical application., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Procalcitonin (PCT) protein has recently been identified as a clinical marker for bacterial infections based on its better sepsis sensitivity. Thus, an increased level of PCT could be linked with disease diagnosis and therapeutics. In this study, we describe the construction of the photoelectrochemical (PEC) PCT immunosensing platform based on it situ grown photo-active CuWO 4 nanospheres over reduced graphene oxide layers (CuWO 4 @rGO). The in situ growth strategy enabled the formation of small nanospheres (diameter of 200 nm), primarily composed of tiny self-assembled CuWO 4 nanoparticles (2-5 nm). The synergic coupling of CuWO 4 with rGO layers constructed an excellent photo-active heterojunction for photoelectrochemical (PEC) sensing. The platform was then considered for electrocatalytic (EC) mechanism-based detection of PCT, where inhibition of the photocatalytic oxidation signal of ascorbic acid (AA), subsequent to the antibody-antigen interaction, was recorded as the primary signal response. This inhibition detection approach enabled sensitive detection of PCT in a concentration range of 10 pg·mL -1 to 50 ng.mL -1 with signal sensitivity achievable up to 0.15 pg·mL -1 . The proposed PEC hybrid (CuWO 4 @rGO) could further be engineered to detect other clinically important species.

This study describes the construction of highly-sensitive photo-electrochemical (PEC) immunosensor for the detection of neuron-specific enolase (NSE). The biosensing platform is comprised of photo-active NiWO 4 nanostructures, in-situ-grown over a conductive substrate (indium tin oxide) using a low-temperature template-based co-precipitation approach. The discussed approach enables the formation of discrete, yet morphologically-analogous, nanostructures with complete coverage (pinhole-free) of the electrode surface. The in-situ-grown nanostructure possess dense population with sharp saw-blade like morphological features that can support substantial immobilisation of anti-NSE agent. The constructed platform demonstrated excellent photo-catalytic activity towards uric acid (UA) which served as the base for the Electrochemical -mechanism (EC) based PEC inhibition sensing. The detection of NSE, relied on its obstruction in analytical signal observed for the photo-oxidation of UA after binding to the electrode surface via protein-antibody interaction. The constructed PEC immunosensor exhibits signal sensitivity up to 0.12 ng mL -1 of NSE with excellent signal reproducibility and electrode replicability. Moreover, the constructed platform was successfully used for NSE determination in human serum samples., (Copyright © 2019 Elsevier B.V. All rights reserved.)