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Direct electrochemical detection of clinically significant and emerging pharmaceutical pollutants, such as nitrofurantoin, is a critical challenge. Herein, we propose an efficient electroactive platform composed of Pd nanocubes (Pd NCs) embedded within partially oxidized MXenes (Ti 3 C 2 T x -TiO 2). This proximity between Pd NCs, in-situ generated TiO 2 , and Ti 3 C 2 T x results in a highly compact and efficient architecture, facilitating enhanced charge transfer and electrocatalytic activity, which results in an efficient cathodic reduction to NFT at a much lower-over potential of − 0.4 V. The optimal composite configuration (Pd-Ti 3 C 2 T x -P) enabled NFT detection in a dynamic concentration range from 1 to 140 nM, with a detection sensitivity reaching down to 0.01 nM (S/N = 3) against Ag/AgCl as the reference electrode. Furthermore, the developed sensor demonstrated outstanding selectivity toward NFT while tolerating probable interfering substances such as biomolecules, drugs, and metal ions. The sensor can detect NFT selectively in complicated environmental matrices such as hospital waste effluent samples. The proposed design offers a simple route to construct advanced electrocatalytic sensors with potential applications in monitoring emerging pharmaceutical pollutants. [Display omitted] • Pd NCs with partially oxidized MXenes as a synergistic electrocatalytic platform. • Redox activity from Pd NCs and conductivity from MXenes synergistically reduce NFT. • Low-overpotential-based outstanding selectivity for NFT in environmental samples. [ABSTRACT FROM AUTHOR]

This study describes the application of gold nanocages (Au NCs) for the development of enzyme free electrochemical glucose sensor. The described sensor system is based on the direct modification of glassy carbon electrode (GCE) with Au NCs prepared using simple galvanic replacement reaction. The excellent sensitivity in this case was attributed to the high surface area (interior/exterior) and cavity confinement phenomena (cage effect) associated with Au NCs during the oxidation of glucose. The observed electro-catalytic cage confinement phenomena for Au NCs was elaborately studied using cyclic voltammetry (CV) against solid gold nanoparticles (Au NPs) modified electrode. In addition to this, the developed sensor system was found highly resistive towards interfering species such as uric acid (UA), ascorbic (AS), dopamine (DP) and monosaccharide like fructose (FC) and maltose (ML). The electro-catalytic affinity of Au NCs for the oxidation of glucose enabled development of highly sensitivity (2131 μA cm −2 mM −1 ) and selective sensor with lower detection limit estimated to be 0.1 mM and linear working range of 1.0–9.0 mM. [ABSTRACT FROM AUTHOR]

This work reports a highly sensitive electrochemical sensor for organophosphate pesticide (malathion) based on unique and attractive CuO nanostructures. The discussed nanostructures were synthesized using low temperature hydrothermal growth method utilizing green amino acids such as glycine, serine, threonine and histidine as effective bio-compatible templates. The morphological evaluation demonstrated formation of unique and attractive 1-D nanostructures reflecting the effective growth controlling and directing capabilities of the utilized amino acids. The as-synthesized CuO nanostructures were noted to possess high affinity towards malathion which enabled their application as electrode material for the development of affinity based electrochemical sensor. Although, the as-synthesized morphologies were all sensitive towards malathion but the glycine directed triangular flake-like nanostructures exhibited greater sensitivity compared to other competitors. The electrochemical behaviour of the modified electrodes was studied using cyclic voltammetry (CV) whereas, differential pulse voltammetry (DPV) was utilized for the analytical evaluation of the sensor. The developed sensor demonstrated high reproducibility, stability, wide detection window (1–12 nM), and sensitivity to detect malathion up to 0.1 nM based on suppressive signal measurement. In addition, the sensor system exhibited high anti-interference capability in the presence of common co-existing pesticides like lindane, carbendazim, and trichlorfon. The developed sensor provides an effective measure for detecting extremely low concentration of malathion with wide applicability in various fields. [ABSTRACT FROM AUTHOR]

The study reports the synthesis of cobalt oxide (Co 3 O 4 ) nanostructures and their application in enzyme free electrochemical sensing of glucose. The synthesized nanostructures were elaborately characterized via number of analytical techniques including scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The as-synthesized nanostructures of Co 3 O 4 were found to exhibited nanodisc like morphology with the size dimension in range of 300–500 nm. The obtained morphological features were evaluated for their electrochemical potential towards oxidation of glucose which enabled development of sensitive (27.33 µA mM −1 cm −2 ), and stable enzyme free glucose sensor. In addition, the developed sensor showed excellent linearity ( r 2 =0.9995), wide detection range (0.5–5.0 mM), lower detection limit (0.8 µM) and extreme selectivity towards glucose in the presence of common interferents like dopamine (DP), ascorbic acid (AA) and uric acid (UA). The successfully application of developed sensor for real blood glucose analysis further reflects its capability for routine glucose measurement. [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]

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. • Partially oxidized MXene-based hybrid for PEC sensing. • BiVO 4 /TiO 2 /Ti 3 C 2 T x -based heterojunction as photo active platform. • Photo-active electrode for sensitive detection of CD44 proteins. [ABSTRACT FROM AUTHOR]

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. • In-situ-grown photo active saw-blade-like NiWO 4 nanostructures. • PEC immunosensor for the detection of neuron-specific enolase. • Binder-free photo-active electrode for sensitive detection of NSE. [ABSTRACT FROM AUTHOR]

The construction of high-performance photocatalysts plays a pivotal role in realizing the efficient conversion of solar energy-hydrogen energy. In this work, we employed an electrostatic self-assembly approach to couple Cd 0.3 Mn 0.7 S with FeS 2 , thereby fabricating the FeS 2 /Cd 0.3 Mn 0.7 S S-scheme heterojunction. When used as a catalyst, the heterojunction achieved a photocatalytic hydrogen evolution activity of 11.88 mmol/g/h, utilizing the full spectrum region. This performance was 66.7 and 1.5 times higher than that of FeS 2 and Cd 0.3 Mn 0.7 S, respectively. Furthermore, the as-fabricated FeS 2 /Cd 0.3 Mn 0.7 S exhibited long-term stability, with hydrogen production demonstrating a linear growth trend over the irradiation time. The enhancement in photocatalytic performance was attributed to the formation of the S-scheme heterojunction, which boosts the separation efficiency of charge carriers through interface engineering, thereby improving light energy utilization. Additionally, FeS 2 served as an efficient cocatalyst, providing active sites for photocatalytic hydrogen production. This work offers valuable insights into the rational design of efficient cocatalysts and the construction of S-scheme heterojunctions. • FeS 2 /Cd 0.3 Mn 0.7 S heterojunction photocatalysts were constructed via electrostatic self-assembly method. • The strong interaction in FeS 2 /Cd 0.3 Mn 0.7 S interface can boost the spatial separation/transfer of photogenerated carriers. • The HER activity of 20%FeS 2 /Cd 0.3 Mn 0.7 S is 66.7 and 1.5 times higher than that of FeS 2 and Cd 0.3 Mn 0.7 S. • The enhanced HER activity of FeS 2 /Cd 0.3 Mn 0.7 S is attributed to formation of the S-scheme heterojunction. [ABSTRACT FROM AUTHOR]

The study explores the potential of newly developed ITO based electrode for the electro-catalytic detection of Sudan I. The ITO based electrode utilizes a dense layer of 2D CuO nanostructures as an effective electron-transfer facilitator which promotes the electro-catalytic sensing of Sudan I in aqueous solution. The in-situ growth of CuO nanostructures was achieved using simple hydrothermal route with the assistance of tartaric acid utilized as an effective template. The in-situ grown layer comprises of 2D CuO nanostructures with morphological features similar to flowers composed of sharp-flake like features. The electro-catalytic oxidation of Sudan I over the described electrode system demonstrated low-over potential value and excellent working stability with good analytical linearity in the range of 0.001–1.56 µM. The ITO based electrode was found highly selective and sensitive towards Sudan I with limit of detection determined to be 1.2 × 10 −4 µM (S/N = 3). [ABSTRACT FROM AUTHOR]

In this report, we firstly synthesized nitro calix [4] resorcinarene compound (referred as KA30) and characterized it though proton (1H) 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. [Display omitted] • Nitro calix [4] resorcinarene (KA30) was synthesized via facile procedure. • KA30 was used as capping agent for the synthesis of silver nanoparticles (AgNPs). • These AgNPs were used as colorimetric sensor for low level detection of emamectin. • The colorimetric sensor was allied with smartphone for improved detection. • The sensor was used for emamectin detection in food, biofluids and water samples. [ABSTRACT FROM AUTHOR]

Cadmium (Cd2+) has been declared as possible cancer causing heavy metal ion in humans and animals. Here in this research work we used an economical, facile, simpler, and one pot method for the formation of secnidazole derived silver nanoparticles (SEC-AgNPs). SEC-AgNPs were characterized through advanced techniques like, ultraviolet-visible (UV-Vis) spectroscopy, Fourier Transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS) technique, zeta potential (ZP) analysis, field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). These prepared SEC-AgNPs were investigated and verified as extremely sensitive, highly stable, rapidly responding and cost-effective colorimetric sensor for the low level detection of Cd2+. As-developed colorimetric Cd2+ sensor proved to be extremely selective in the presence of eighteen monovalent, divalent, trivalent and tetravalent metal ions and associated anions showing negligible interference with even ten-fold greater concentration of these ions as compared to Cd2+. The SEC-AgNPs based colorimetric Cd2+ sensor was linearly responsive to Cd2+ in the range of 5–27 µM with limit of detection (LOD) equal to 0.021 µM and LOQ value of 0.07 µM with R2 of 0.9965. The newly developed SEC-AgNPs based colorimetric sensor was successfully applied for cadmium detection in real tap water sample and human blood plasma samples within acceptable recovery levels. • Secnidazole based silver nanoparticles (SEC-AgNPS) were formed easily. • SEC-AgNPs were characterized through advanced techniques. • SEC-AgNPs were verified as highly sensitive colorimetric sensor for Cd2+. • As-prepared sensor was stable, rapid, highly selective and cost-effective. • The sensor was effectively applied for Cd2+ detection in real samples. [ABSTRACT FROM AUTHOR]

The increasing need for high-performance energy storage systems necessitates the exploration of novel electrode materials. In this study, the utilization of polyaniline/multiwalled carbon nanotubes (PANI/MWCNTs) was demonstrated as a conductive scaffold for the formation of heterostructures comprising nickel manganese phosphate (NiMn(PO 4) 2) using probe sonication, leading to the development of an efficient hybrid supercapacitor. The PANI/MWCNTs composite exhibits favorable conductive properties, acting as a suitable framework for the nucleation/growth and integrating NiMn(PO 4) 2 structures. The synergistic combination of PANI/MWCNTs and NiMn(PO 4) 2 resulted in the development of a highly efficient hybrid anode, exhibiting a remarkable specific capacitance of 917.3 F g‐1 (912.2 C g−1) at 1 A g‐1 in a 1 M KOH electrolyte. The optimized composite, PCNT-NMP-40, as a positive electrode in a two-electrode cell configuration with activated carbon (AC) as the negative electrode, operates within an extended output potential range of 0–1.6 V in a 2 M KOH electrolyte, delivering an outstanding energy density of 58 Wh kg−1 and a power density of 918 W kg−1, reflecting the substantial potential use of PCNT-NMP-40 as an excellent candidate for advanced energy storage applications. [ABSTRACT FROM AUTHOR]

Ceramic supported graphene oxide (GO)/Attapulgite (ATP) composite membrane (GOA) was simply prepared by vacuum filtration for efficient removal of heavy metal contamination. The ATP nanorods were incorporated within the laminar layers of GO, influencing the interlayer distance and facilitating greater number of channels for enhanced water transportation. The GOA possessed greater surface wettability with improved water flux rate of 6.3 L m−2 h−1 compared to 0.4 L m−2 h−1 measured for its pristine counter-part. The GOA demonstrated excellent rejection efficiency (nearly 100%) for heavy metal ions such as Cu2+, Ni2+, Pb2+ and Cd2+. The excellent separation efficiency of GOA could be ascribed to the synergic combination of size exclusion effect based on the formation of 3D network structures between the GO layers and increased electrostatic interaction in between the negatively charged surface moieties of GOA and heavy metal ions. More importantly, the use of Al 2 O 3 as a support substrate resulted in improved stability and allowed extended usage of the membrane for a period of 3500 min while maintaining 99% rejection efficiency for Cu2+ ions. The high flux rate, great water stability and prominent rejection capability of the designed membrane is suggestive of its practical application in removal of heavy metal contamination from water. Image 1 • Ceramic supported GO-ATP membrane was simply prepared by vacuum filtration. • Incorporation of ATP nanorods enhances the surface wettability and water flux. • Al 2 O 3 is an excellent substrate support that prolonged the stability of the GOA. • The GOA demonstrates excellent water stability with high flux rate. • The GOA exhibits excellent rejection of nearly 100% for heavy metal ions. [ABSTRACT FROM AUTHOR]

The global pandemic of COVID-19 poses significant challenge to the recycling of disposable polypropylene (PP)-based waste masks. Herein, a simple but effective sulfonation route has been proposed to transform PP-based waste masks into value-added hard carbon (CM) anode materials for advanced sodium-ion batteries. The sulfonation treatment improves the thermal stability of the PP molecule, preventing their complete decomposition and the release of massive gas molecules during the carbonization process. Meanwhile, the oxygen functional groups introduced during sulfonation effectively facilitates the cross-linking between the PP chains, hindering the rearrangement of carbon microcrystalline structures and enhancing its structural disorder. As a result, the prepared hard carbon anode (CM-180) with a high disorder degree and minimal surface defects realizes a high sodium storage capacity of 327.4 mAh g−1 with excellent cycle and rate capability. In addition, when coupled with O 3 –NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathode, the fabricated sodium-ion full cell delivers a high energy density of 238 Wh kg−1 and achieves an outstanding rate capability with a retained capacity of 75 mAh g−1 even at an ultrahigh current rate of 50 C. This work offers a novel insight into transforming the waste masks to value-added hard carbons with promising prospects for sodium-ion batteries. [Display omitted] • Masks-derived hard carbons are prepared via sulfonation-carbonization treatment. • The obtained CM-180 anode delivers a high Na-storage capacity of 327.4 mAh g−1. • The sodium-ion full cells with CM-180 anode realize exceptional rate capability. [ABSTRACT FROM AUTHOR]

Although hard carbons are considered as promising anode candidates for commercial sodium-ion batteries (SIBs), the trade-off between high Na-storage capacity and initial coulombic efficiency (ICE) remains a critical challenge for their practical application. Herein, nitrogen/oxygen co-doped hard carbon microspheres (N/O–HCs) for SIBs are prepared by a simple solvothermal treatment to allow the efficient cross-linking of phenolic resin with melamine and followed high-temperature pyrolysis process. The heteroatom doping promotes structural disordering of hard carbons and generates more active sites for Na ion storage, whereas the cross-linking of melamine with phenol resin efficiently restricts the formation of surface defects. Therefore, the obtained N/O-HC-1200 electrode exhibits both high reversible Na-storage capacity of 319.7 mAh g−1 and much improved ICE of 81.6%. Moreover, the electrode demonstrates excellent cycle and rate performance with the capacity stabilized at 253.9 mAh g−1 at 1C over 1000 cycles. When coupled with NaFe 1/3 Ni 1/3 Mn 1/3 O 2 cathode, the constructed full cell delivers a high energy density of 247.6 Wh kg−1 and outstanding rate capability with a retained capacity of 70 mAh g−1 at an ultrahigh current rate of 50C. The proposed work offers a new perspective on the surface chemistry and structural design of high-performance hard carbon anodes for SIBs. [Display omitted] • N/O co-doped phenol resin-based carbon microspheres (N/O–HCs) have been prepared. • The N/O–HCs achieves both high structural disordering and reduced surface defects. • The N/O-HC-1200 delivers a high capacity of 319.7 mAh g−1 with an ICE of 81.6%. • The capacity of N/O-HC-1200 stabilizes at 253.9 mAh g−1 at 1C over 1000 cycles. [ABSTRACT FROM AUTHOR]