Pioneering food analysis: Transformative antioxidant testing with colorimetric assays using Co-Mn bimetallic oxide nanozyme.

Background: Total antioxidant capacity (TAC) testing is critical for guiding dietary, and nutritional treatments, and investigating the efficacy of antioxidant food additives.

Results: Here, a competitive enzyme-like colorimetric method based on Co-Mn nanoflower nanozymes was developed for the determination of TAC in food. The synthesized nanozymes had excellent POD-like activity, using the antioxidant as a special recognition unit and the chromogenic substrate as a signal molecule reporter, and could generate a significant color response in less than 15 min by producing enzymatically catalyzed ROS.

Miniature dual-channel electrochemical 3D-printed sensing platform for enzyme-free screening of L-lactic acid in foodstuffs accompanying pH recognition.

Accurate and rapid identification of expired and spoiled food is crucial for food conservation, reducing resource wastage, and preventing food poisoning. This paper presents a portable electrochemical sensing platform supported by a miniature electrochemical workstation and an intelligent pH recognition system, enabling detection of L-lactic acid (L-LA) in food products without enzyme involvement. The system was based on a CuO@CuO multifaceted extended spatial hexapod structure.

Smartphone-based point-of-care photoelectrochemical immunoassay coupling with ascorbic acid-triggered photocurrent-polarity conversion switching.

Photocurrent-polarity conversion strategies are typically realized by constructing complex photovoltaic electrodes or changing the relevant conditions, but most involve poor photogenerated carrier transfer efficiency and cumbersome experimental steps. To this end, a photoelectrochemical (PEC) biosensor by utilizing ascorbic acid (AA)-induced photocurrent-polarity-switching was proposed for the detection of carcinoembryonic antigen (CEA). Under light excitation, the electron donor AA was oxidized by the photogenerated holes of photoactive material Co-NC/CdS, resulting in the conversion of cathodic photocurrent to the anodic direction.

Probing trace of intracellularly-originated hydrogen peroxide based Pt-Cd bimetallic nanozyme on an enzyme-free electrochemical sensor.

Background: Measurement of endogenous cellular hydrogen peroxide (HO) can provide information on cellular status, and help to understand cellular metabolism and signaling processes, thus contributing to elucidation of disease mechanisms and new diagnostics/therapeutic approaches.

Results: In this work, Pt-Cd bimetallic nanozyme was successfully prepared via the solvothermal synthetic method for sensitive detection of HO. The synthesized Pt-Cd bimetallic nanozyme could exhibited good electrochemical activity.

Guanine-derived carbon nanosheet encapsulated Ni nanoparticles for efficient CO electroreduction.

Developing novel electrocatalysts for achieving high selectivity and faradaic efficiency in the carbon dioxide reduction reaction (CORR) poses a major challenge. In this study, a catalyst featuring a nitrogen-doped carbon shell-coated Ni nanoparticle structure is designed for efficient carbon dioxide (CO) electroreduction to carbon monoxide (CO). The optimal Ni@NC-1000 catalyst exhibits remarkable CO faradaic efficiency (FE) values exceeding 90% across a broad potential range of -0.

Ternary Photoanodes with AgAu Nanoclusters and CoNi-LDH for Enhanced Photoelectrochemical Water Oxidation.

Atomically precise metal nanoclusters (NCs) present new opportunities for creating innovative solar-powered photoanodes due to their extraordinary physicochemical properties. Nevertheless, ultrasmall metal NCs tend to aggregate and lack active sites under light irradiation, which severely limits their widespread application. We have developed a strategy to design efficient ternary photoanodes by successively modifying AgAu NCs and CoNi-LDH on BiVO substrates using versatile impregnation and electrodeposition.

Pargyline-phosphine copper(I) clusters with tunable emission for light-emitting devices.

Three pargyline-phosphine copper(I) clusters, [Cu(CC-CHN)(PPh)](PF) (1) and [Cu(CC-CHN)(dppy)](X) (dppy = diphenyl-2-pyridylphosphine; X = PF for 2 and X = ClO for 3), were synthesized. Their structures were fully characterized using various spectroscopic methods and X-ray crystallography, which showed that the stoichiometry and nature of pargyline and phosphine ligands play an important role in tuning the structure and photophysical features of Cu(I) clusters. Interestingly, clusters 1, 2 and 3 exhibited red, orange and yellow phosphorescence with high quantum yields of 88.

Edge-generated N-doped carbon-supported dual-metal active sites for enhancing electrochemical immunoassay.

Development of high-precision human epidermal growth factor receptor 2 (HER2) assay is essential for the early diagnostic and prevention of breast cancer. In this work, an innovative Fe/Mn bimetallic nanozyme at the edge of N-doped carbon defects (FeMn-NC) with abundant active sites was prepared through the hydrothermal synthetic method. FeMn-NC nanozyme displayed excellent peroxidase-like activity relative to the HO-catalyzed 3,3',5,5'-tetramethylbenzidine (TMB) system for generation of the oxidized TMB (oxTMB).

Ionic Liquids-Driven Cluster-to-Cluster Conversion of Polyhydrido Copper(I) Clusters CuH to CuH and CuH.

Although ionic liquids (ILs) are of prime interest for the synthesis of various nanomaterials, they are scarcely utilized for the polyhydrido copper(I) [Cu(I)H] clusters. Herein, two air-stable Cu(I)H clusters, [CuH(dppy)](NTf) (CuH) and {CuH(dppy)[N(CN)]} (CuH), are synthesized in high yields for the first time from the ILs-driven conversion of an unprecedented cluster [CuH(dppy)](ClO) (CuH) by a facile three-layers diffusion crystal (TLDC) method, strategically introducing IL-NTf and IL-N(CN) as two types of unusual interfacial crystallized templates, respectively. Their structures are fully characterized by various spectroscopic methods and X-ray crystallography, which shows that the anion of IL plays an important role as an anion template and an anion ligand in controlling the structural conversion of Cu(I)H clusters.

Self-assembled p-n AgO@BiOS nanoflower heterojunctions for sensitive photoelectrochemical immunoassay.

A new photoelectrochemical immunoassay based on self-assembled p-n AgO@BiOS nanoflower heterojunction was designed and developed for quantitative monitoring of prostate-specific antigen (PSA) in biological fluids. Primarily, self-assembled p-n AgO@BiOS nanoflower heterojunctions were served as the photoactive materials and coated onto the surface of electrodes. Subsequently, the glucose oxidase (GOx) was bound to the detection antibody (mAb) labeled gold nanoparticles (Au NPs) and then were employed to accomplish a sandwich-like immunoreaction to generate HO on a microplate incubated with monoclonal anti-PSA antibodies.

High-entropy effect with hollow (ZnCdFeMnCu)S nanocubes for photoelectrochemical immunoassay.

High entropy (HE) compounds with chemically disordered multi-cation structures have become a hot research topic because of their fascinating "cocktail effect". However, high entropy effect with the efficient photoelectric response has not been reported for photoelectrochemical (PEC) immunoassays. Herein, an innovative PEC immunoassay for the sensitive detection of prostate-specific antigen (PSA) was ingeniously constructed using hollow nanocubic (ZnCdFeMnCu)S photoactive matrices with high entropic effect via the cation exchange.

Core-shell MoC@NC/MoC hollow microspheres as highly efficient electrocatalysts for the hydrogen evolution reaction.

Developing low-cost and highly efficient electrocatalysts for the hydrogen evolution reaction (HER) has stimulated extensive interest. Molybdenum carbide materials have been proposed as promising alternatives to noble platinum-based catalysts due to their earth abundance and tunable physicochemical characteristics. Here, we report MoC@NC/MoC hollow microspheres composed of a β-MoC core and small β-MoC particles embedded within a nitrogen-doped carbon shell and prepared using guanosine and hexaammonium molybdate as precursors a hydrothermal self-assembly process, which results in outstanding catalytic activity and fast kinetics in hydrogen evolution in both acidic and alkaline solutions.

Ag/MoO-Pd-mediated gasochromic reaction: An efficient dual-mode photoelectrochemical and photothermal immunoassay.

Herein, we presented a dual-readout gasochromic immunosensing platform for accurate and sensitive detection of carcinoembryonic antigen (CEA) based on Ag-doped/Pd nanoparticles loaded MoO nanorods (Ag/MoO-Pd). Initially, the presence of analyte CEA would prompt the formation of sandwich-type immunoreaction, accompanied by the introduction of Pt NPs labeled on detection antibody. Upon the addition of NHBH, the product hydrogen (H) will interact with Ag/MoO-Pd as a bridge between the sensing interface and the biological assembly platform.

Smartphone-based photoelectrochemical immunoassay of prostate-specific antigen based on Co-doped BiOS nanosheets.

Portable and on-site detection of target biomarker is of great significance in early diagnosis of diseases. Herein, we designed a portable smartphone-based PEC immunoassay platform to detect prostate specific antigen (PSA) adopting Co-doped BiOS nanosheets as photoactive materials. The fast photocurrent response under visible light and excellent electrical transport rate invest Co-doped BiOS with the property of being effectively excited even under a weak light source.

Bio-inspired nanozyme with ultra-thin Fe-BiOS nanosheets for in-situ amplified photoelectrochemical immunoassay of cancer-related protein.

A Fe-loaded BiOS nanosheet photoanode serving as photoelectric biomonitoring platform for the detection of prostate-specific antigen (PSA) using biologically inspired prussian nanoparticle (PB)-catalyzed biocatalytic precipitation strategy was developed. Primarily, the signal probe PB-mAb obtained by electrostatic adsorption was immobilized on a microplate in the presence of target PSA, and 4-chloro-1-naphthol (4-CN) was oxidized to benzo-4-chloro-hexadienone (4-CD) with the assistance of exogenous hydrogen peroxide, which was generated by a large number of hydroxyl radicals catalyzed by PB. The generated 4-CD showed strongly low conductivity characteristics to burst the photocurrent of highly photoactive Fe-BiOS photoanode.

A Composite of Two Dimensional GeSe /Nitrogen-Doped Reduced Graphene Oxide for Enhanced Capacitive Lithium-Ion Storage.

A composite of two-dimensional (2D) GeSe nanosheets dispersed on N-doped reduced graphene oxide (GeSe /N-rGO) is fabricated via a simple hydrothermal method combined with post-selenization process. The high electronic conductivity and the substantial void spaces of the wrinkled N-rGO can improve the electrical conductivity of the active material and accommodate the volume evolution of GeSe nanosheets during the (de)lithiation processes, while GeSe nanosheets can reduce ion diffusion length effectively. Meanwhile, the unique layered structure is beneficial to the contact of the active material and electrolyte, and the reversibility of conversion reaction has also been improved.

Bioinspired Self-Powered Piezoresistive Sensors for Simultaneous Monitoring of Human Health and Outdoor UV Light Intensity.

The exact fabrication of precise three-dimensional structures for piezoresistive sensors necessitates superior manufacturing methods or tooling, which are accompanied by time-consuming processes and the potential for environmental harm. Herein, we demonstrated a method for synthesis of zinc oxide nanorod (ZnO NR) arrays on graphene-treated cotton and paper substrates and constructed highly sensitive, flexible, wearable, and chemically stable strain sensors. Based on the structure of pine trees and needles in nature, the hybrid sensing layer consisted of graphene-attached cotton or paper fibers and ZnO NRs, and the results showed a high sensitivity of 0.

Graphene-coated copper-doped ZnO quantum dots for sensitive photoelectrochemical bioanalysis of thrombin triggered by DNA nanoflowers.

This work reports a photoelectrochemical (PEC) biosensing platform for the sensitive and specific screening of thrombin by using graphene oxide-coated copper-doped zinc oxide quantum dots (CuZnO-GO QDs) as the photoactive materials and glucose oxidase-encapsulated DNA nanoflowers (GOx-DFs) for signal amplification. Interestingly, the coated graphene oxide nanosheets on the surface of the CuZnO QDs could cause the charge to transfer rapidly and ameliorate the photocorrosion. The doped copper into the quantum dots could enhance the absorption of visible light by tuning the band gap of ZnO QDs, therefore increasing the photocurrent under visible irradiation.

Novel ultrabright luminescent copper nanoclusters and application in light-emitting devices.

Two newly synthesized ultra-small copper nanoclusters, [Cu(μ-H)(μ-dppy)](ClO) (1) and [Cu(μ-H)(μ-dppy)(μ-Cl)](ClO) (2) (dppy = diphenyl-2-pyridylphosphine), have been shown to exhibit ultrabright yellow and yellow-green room-temperature phosphorescence (RTP) emission, with high quantum yields of 71.8% and 63.5%, respectively.

Single-atom cobalt-fused biomolecule-derived nitrogen-doped carbon nanosheets for selective oxidation reactions.

Non-noble metal single-atom catalysts hold great promise in selective oxidation reactions, although the progress is still unsatisfactory because of the synthesis challenge and the lack of mechanistic interpretations. Herein, we develop a biomolecule-based strategy to synthesize isolated Co single atom site catalysts by one-step pyrolysis of guanosine and Co precursors. Due to the abundant hydrogen bonding and π-π interaction of guanosine, the as-synthesized Co-N-C catalysts present a hierarchical porous two-dimensional (2D) nanostructure with an ultrahigh specific surface area, large pore volume, and high density of cobalt single atoms.

Stable Li-ion storage in Ge/N-doped carbon microsphere anodes.

The development of environmentally benign, low-cost and high-performance Ge-based materials for lithium-ion batteries (LIBs) has remained a great challenge. Herein, the synthesis of Ge/N-doped carbon microspheres (Ge/NC) is firstly performed using N-(2hydroxyethyl)ethylenediamine (AEEA) and ethanediamine (EDA) as solvents, ligands and carbon sources. The three-dimensional Ge/NC microspheres prepared with AEEA (Ge/NC-A) are constructed from nanosheets with a thickness of about 20 nm.

Luminescent Ionogels with Excellent Transparency, High Mechanical Strength, and High Conductivity.

The paper describes a new kind of ionogel with both good mechanical strength and high conductivity synthesized by confining the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([Bmim][NTf]) within an organic-inorganic hybrid host. The organic-inorganic host network was synthesized by the reaction of methyltrimethoxysilane (MTMS), tetraethoxysilane (TEOS), and methyl methacrylate (MMA) in the presence of a coupling agent, offering the good mechanical strength and rapid shape recovery of the final products. The silane coupling agent 3-methacryloxypropyltrimethoxysilane (KH-570) plays an important role in improving the mechanical strength of the inorganic-organic hybrid, because it covalently connected the organic component MMA and the inorganic component SiO.

Novel luminescent homo/heterometallic platinum(ii) alkynyl complexes based on Y-shaped pyridyl diphosphines.

A series of dinuclear platinum(ii) alkynyl complexes [Pt2L2(C[triple bond, length as m-dash]CC6H4R-4)4] (R = H 1, CH32, But3) and unusual tetranuclear Pt(ii)-Ag(i) clusters [Pt2Ag2L(C[triple bond, length as m-dash]CC6H4R-4)6] (R = H, 4; CH3, 5; But, 6), together with novel polymer crystals [Pt2Ag2L(C[triple bond, length as m-dash]CC6H5)6]∞ ([4]∞), were synthesized by a self-assembly reaction between [NBu4]2[Pt(C[triple bond, length as m-dash]CC6H4-R-4)4] and [Ag6L6]6+ (L = 4-(3,5-(diphenylphosphine)phenyl)pyridine). These complexes were characterized by using a range of spectroscopic techniques and complexes 1, 3, 5, and [4]∞ were analysed by X-ray crystallography. Each platinum atom of the Pt(ii)-Ag(i) clusters shows an unusual asymmetric distorted square planar geometry with three alkynyl groups and one bridging L phosphorus atom.

Nucleobase derived boron and nitrogen co-doped carbon nanosheets as efficient catalysts for selective oxidation and reduction reactions.

The search for active, stable and cost-efficient carbocatalysts for selective oxidation and reduction reactions could make a substantial impact on the catalytic technologies that do not rely on conventional metal based catalysts. Here we report a facile strategy for the synthesis of boron (B) and nitrogen (N) co-doped carbon nanosheets (BNC) by using biomolecule guanine as a carbon (C) and N source and boric acid as the B precursor. The whole synthesis process which leads to the formation of a two dimensional (2D) structure and mesoporosity with high surface areas is simple, metal-free and template-free.

One-Step Synthesis of N, P-Codoped Carbon Nanosheets Encapsulated CoP Particles for Highly Efficient Oxygen Evolution Reaction.

Oxygen electrocatalysis, especially oxygen evolution reaction (OER), is a central process during the actual application of rechargeable metal-air battery. It is still challenging to develop ideal electrocatalysts to substitute the commercial noble metal-based materials. In this work, we have constructed a new material, CoP nanoparticles, which are encapsulated by a biomolecule-derived N, P-codoped carbon nanosheets via a simple and facile one-step strategy.