A small-molecule carrier for the intracellular delivery of a membrane-impermeable protein with retained bioactivity.

Intracellular protein delivery has the potential to revolutionize cell-biological research and medicinal therapy, with broad applications in bioimaging, disease treatment, and genome editing. Herein, we demonstrate successful delivery of a functional protein, cytochrome c (CYC), by using a boron cluster anion as molecular carrier of the superchaotropic anion type (B12Br11OPr2-). CYC was delivered into lipid bilayer vesicles as well as living cells, with a cellular uptake ratio approaching 90%. Mechanistic studies showed that CYC was internalized into cells through a permeation pathway directly into the cytoplasm, bypassing endosomal entrapment. Upon carrier-assisted internalization, CYC retained its bioactivity, as reflected by an induced cell apoptosis rate of 25% at low dose (1 µM). This study furbishes a direct protein delivery method by a molecular carrier with high efficiency, confirming the potential of inorganic cluster ions as protein transport vehicles with an extensive range of future cell-biological or biomedical applications.

A Wearable Electrochemical Biosensor Utilizing Functionalized Ti3C2Tx MXene for the Real-Time Monitoring of Uric Acid Metabolite.

Wearable, noninvasive sensors enable the continuous monitoring of metabolites in sweat and provide clinical information related to an individual's health and disease states. Uric acid (UA) is a key indicator highly associated with gout, hyperuricaemia, hypertension, kidney disease, and Lesch-Nyhan syndrome. However, the detection of UA levels typically relies on invasive blood tests. Therefore, developing a wearable device for noninvasive monitoring of UA concentrations in sweat could facilitate real-time personalized disease prevention. Here, we introduce 1,3,6,8-pyrene tetrasulfonic acid sodium salt (PyTS) as a bifunctional molecule functionalized with Ti3C2Tx via π-π conjugation to design nonenzymatic wearable sensors for sensitive and selective detection of UA concentration in human sweat. PyTS@Ti3C2Tx provides many oxidation-reduction active groups to enhance the electrocatalytic ability of the UA oxidation reaction. The PyTS@Ti3C2Tx-based electrochemical sensor demonstrates highly sensitive detection of UA in the concentration range of 5 µM-100 µM, exhibiting a lower detection limit of 0.48 µM compared to the uricase-based sensor (0.84 µM). In volunteers, the PyTS@Ti3C2Tx-based wearable sensor is integrated with flexible microfluidic sweat sampling and wireless electronics to enable real-time monitoring of UA levels during aerobic exercise. Simultaneously, it allows for comparison of blood UA levels via a commercial UA analyzer. Herein, this study provides a promising electrocatalyst strategy for nonenzymatic electrochemical UA sensor, enabling noninvasive real-time monitoring of UA levels in human sweat and personalized disease prevention.

A Wearable Electrochemical Sensor Based on Single-Atom Pt Anchored on Activated NiCo-LDH/Ti3C2Tx for Real-Time Monitoring of Glucose.

Wearable, noninvasive sweat sensors enable real-time monitoring of metabolites in human health management. However, the commercial enzyme-based and currently nonenzymatic glucose sensor represents sluggish glucose oxidation kinetics and a narrow sensing range. Rational design of sensitive materials is significant yet faces a huge challenge. Herein, we construct a single-atom Pt supported on NiCo-LDH/Ti3C2Tx heterostructures (Pt1-NiCo-LDH/Ti3C2Tx) as the nonenzymatic electrochemical glucose sensor sensitive materials for selective detection of glucose level in human sweat. The obtained Pt1-NiCo-LDH/Ti3C2Tx with improved structural stability and enhanced charge transfer efficiency shows a low oxidation peak potential of 0.49 V, high sensitivity of 506.6 µA mM-1 cm-2, a low detection limit of 0.035 µM, and long-term stability toward the glucose detection. The wearable sensor, coupled with a wireless transmission module and a signal processing chip, is used for real-time perspiration glucose monitoring during outdoor exercise. The result is comparable to that of high-performance liquid chromatography (HPLC). This research provides a new paradigm for designing a wearable nonenzymatic electrochemical glucose sensor, enabling noninvasive real-time monitoring of glucose concentrations in human sweat.

Glycan-Evocated Metallization for Amplification-Free Electrochemical Detection of Glycoproteins at Low Concentration Levels.

Glycoproteins have become the most often screened tumor markers in the in vitro diagnostics. Although a large number of electrochemical methods have been proposed to sensitively detect glycoproteins, most of them involve the aid of laborious signal amplification. Herein, we report the use of glycan-evocated metallization (GlyMetal) for the amplification-free electrochemical detection of glycoproteins at low concentration levels. Briefly, the glycoproteins of interest are captured by an aptamer recognition layer, and then the glycans of targets are oxidized by NaIO4 to convert the 1,2-diol sites into aldehyde groups for the silver deposition-based metallization, followed by the electrochemical stripping assay of the deposited metallic silver for glycoprotein quantification via the established solid-state Ag/AgCl voltammetric process. As GlyMetal can enable the deposition of a large amount of metallic silver and a high signal-to-background ratio can be obtained for the solid-state Ag/AgCl voltammetric stripping assay, the developed GlyMetal-based electrochemical method is applicable to the amplification-free detection of glycoproteins. As a proof of concept, a detection limit of 1.65 pg/mL has been achieved for carcinoembryonic antigen (CEA) detection. In addition to the high selectivity, desirable results have been obtained with respect to the use of the method for CEA detection in serum samples. In consideration of the desirable simplicity, short assay time, and cost-effectiveness of the amplification-free approach, the GlyMetal-based electrochemical method shows great promise in the point-of-care detection of glycoproteins.

Site-Directed Electrochemical Grafting for Amplified Detection of Antibody Pharmaceuticals.

Antibody pharmaceuticals have become the most popular immunotherapeutic drugs and are often administered with low serum drug dosages. Hence, the development of a highly sensitive method for the quantitative assay of antibody levels is of great importance to individualized therapy. On the basis of the dual signal amplification by the glycan-initiated site-directed electrochemical grafting of polymer chains (glyGPC), we report herein a novel strategy for the amplified electrochemical detection of antibody pharmaceuticals. The target of interest was affinity captured by a DNA aptamer ligand, and then the glycans of antibody pharmaceuticals were decorated with the alkyl halide initiators (AHIs) via boronate cross-linking, followed by the electrochemical grafting of the ferrocenyl polymer chains from the glycans of antibody pharmaceuticals through the electrochemically controlled atom transfer radical polymerization (eATRP). As the glycans can be decorated with multiple AHIs and the grafted polymer chains are composed of tens to hundreds of electroactive tags, the glyGPC-based strategy permits the dually amplified electrochemical detection of antibody pharmaceuticals. In the presence of trastuzumab (Herceptin) as the target, the glyGPC-based strategy achieved a detection limit of 71.5 pg/mL. Moreover, the developed method is highly selective, and the results of the quantitative assay of trastuzumab levels in human serum are satisfactory. Owing to its uncomplicated operation and cost-effectiveness, the glyGPC-based strategy shows great promise in the amplified electrochemical detection of antibody pharmaceuticals.

Exploration of Novel Meso-C═N-BODIPY-Based AIE Fluorescent Rotors with Large Stokes Shifts for Organelle-Viscosity Imaging.

The research on fluorescent rotors for viscosity has attracted extensive interest to better comprehend the close relationships of microviscosity variations with related diseases. Although scientists have made great efforts, fluorescent probes for cellular viscosity with both aggregation-induced emissions (AIEs) and large Stokes shifts to improve sensing properties have rarely been reported. Herein, we first report four new meso-C═N-substituted BODIPY-based rotors with large Stokes shifts, investigate their viscosity/AIE characteristics, and perform cellular imaging of the viscosity in subcellular organelles. Interestingly, the meso-C═N-phenyl group-substituted probe 6 showed an obvious 594 nm fluorescence enhancement in glycerol and a moderate 650 nm red AIE emission in water. Further, on attaching CF3 to the phenyl group, a similar phenomenon was observed for 7 with red-shifted emissions, attributed to the introduction of a phenyl group, which plays a key role in the red AIE emissions and large Stokes shifts. Comparatively, for phenyl-group-free probes, both the meso-C═N-trifluoroethyl group and thiazole-substituted probes (8 and 9) exhibited good viscosity-responsive properties, while no AIE was observed due to the absence of phenyl groups. For cellular experiments, 6 and 9 showed good lysosomal and mitochondrial targeting properties, respectively, and were further successfully used for imaging viscosity through the preincubation of monensin and lipopolysaccharide (LPS), indicating that C═N polar groups potentially work as rotatable moieties and organelle-targeting groups, and the targeting difference might be ascribed to increased charges of thiazole. Therefore, in this study, we investigated the structural relationships of four meso-C═N BODIPY-based rotors with respect to their viscosity/AIE characteristics, subcellular-targeting ability, and cellular imaging for viscosity, potentially serving as AIE fluorescent probes with large Stokes shifts for subcellular viscosity imaging.

Target-Synergized Biologically Mediated RAFT Polymerization for Electrochemical Aptasensing of Femtomolar Thrombin.

The assay of thrombin levels is integral to the assessment of coagulation function and clinical screening of coagulation disorder-related diseases. In this work, we illustrate the ingenious use of the target-synergized biologically mediated reversible addition-fragmentation chain transfer (RAFT) polymerization (tsBMRP) as a novel amplification strategy for the electrochemical aptamer-based biosensing of thrombin at the femtomolar levels. Briefly, the tsBMRP-based strategy relies on the boronate affinity-mediated decoration of the glycan chain(s) of the target itself with RAFT agents and the subsequent recruitment of signal labels via BMRP, mediated by the direct reduction of RAFT agents by NADH into initiating/propagating radicals. Obviously, the tsBMRP-based strategy is biologically friendly, low-cost, and simple in operation. As thrombin is a glycoconjugate, its electrochemical aptasensing involves the use of the thrombin-binding aptamer (TBA) as the recognition receptor, the site-specific decoration of RAFT agents to the glycan chain of thrombin via boronate affinity, and further the recruitment of ferrocene signal labels via the BMRP of ferrocenylmethyl methacrylate (FcMMA). As boronate affinity results in the decoration of each glycan chain with tens of RAFT agents while BMRP recruits hundreds of signal labels to each RAFT agent-decorated site, the tsBMRP-based strategy allows us to detect thrombin at a concentration of 35.3 fM. This electrochemical aptasensor is highly selective, and its applicability to thrombin detection in serum samples has been further demonstrated. The merits of high sensitivity and selectivity, low cost, good anti-interference capability, and simple operation make the tsBMRP-based electrochemical thrombin aptasensor great promise in biomedical and clinical applications.

Amplification-Free Ratiometric Electrochemical Aptasensor for Point-of-Care Detection of Therapeutic Monoclonal Antibodies.

The rapid quantification of therapeutic monoclonal antibodies (mAbs) is of great significance to their pharmacokinetics/pharmacodynamics (PK/PD) research and the personalized medication for disease treatment. Taking advantage of the direct decoration of tens of redox tags to the target of interest, we illustrate herein an amplification-free ratiometric electrochemical aptasensor for the point-of-care (POC) detection of trace amounts of therapeutic mAbs. The POC detection of therapeutic mAbs involved the use of the methylene blue (MB)-conjugated aptamer as the affinity element and the decoration of therapeutic mAbs with ferrocene (Fc) tags via the boronate crosslinking, in which the MB-derived peak current was used as the reference signal, and the peak current of the Fc tag was used as the output signal. As each therapeutic mAb carries tens of diol sites for the site-specific decoration of the Fc output tags, the boronate crosslinking enabled the amplification-free detection, which is cost-effective and quite simple in operation. In the presence of bevacizumab (BevMab) as the target, the resulting ratiometric signal (i.e., the IFc/IMB value) exhibited a good linear response over the range of 0.025-2.5 µg/mL, and the limit of detection (LOD) of the electrochemical aptasensor was 6.5 ng/mL. Results indicated that the aptamer-based affinity recognition endowed the detection of therapeutic mAbs with high selectivity, while the ratiometric readout exhibited satisfactory reproducibility and robustness. Moreover, the ratiometric electrochemical aptasensor is applicable to the detection of therapeutic mAbs in serum samples. Taking together, the amplification-free ratiometric electrochemical aptasensor holds great promise in the POC detection of therapeutic mAbs.

Dually Amplified Electrochemical Aptasensor for Endotoxin Detection via Target-Assisted Electrochemically Mediated ATRP.

As the entering of bacterial endotoxin into blood can cause various life-threatening pathological conditions, the screening and detection of low-abundance endotoxin are of great importance to human health. Taking advantage of signal amplification by target-assisted electrochemically mediated atom transfer radical polymerization (teATRP), we illustrate herein a simple and cost-effective electrochemical aptasensor capable of detecting endotoxin with high sensitivity and selectivity. Specifically, the aptamer receptor was employed for the selective capture of endotoxin, of which the glycan chain was then decorated with ATRP initiators via covalent coupling between the diol sites and phenylboronic acid (PBA) group, followed by the recruitment of ferrocene signal reporters via the grafting of polymer chains through potentiostatic eATRP under ambient temperature. As the glycan chain of endotoxin can be decorated with hundreds of ATRP initiators while the further grafting of polymer chains through eATRP can recruit hundreds to thousands of signal reporters to each initiator-decorated site, the teATRP-based strategy allows for the dual amplification of the detection signal. This dually amplified electrochemical aptasensor has the ability to sensitively and selectively detect endotoxin at a concentration as low as 1.2 fg/mL, and its practical applicability has been further demonstrated using human serum samples. Owing to the simplicity, high efficiency, biocompatibility, and inexpensiveness of the teATRP-based amplification strategy, this electrochemical aptasensor holds great application potential in the sensitive and selective detection of low-abundance endotoxin and many other glycan chain-containing bio-targets.

Development of meso-Five-Membered Heterocycle BODIPY-Based AIE Fluorescent Probes for Dual-Organelle Viscosity Imaging.

Fluorescent rotors with aggregation-induced emission (AIE) and organelle-targeting properties have attracted great attention for sensing subcellular viscosity changes, which could help understand the relationships of abnormal fluctuations with many associated diseases. Despite the numerous efforts spent, it remains rare and urgent to explore the dual-organelle targeting probes and their structural relationships with viscosity-responsive and AIE properties. Therefore, in this work, we reported four meso-five-membered heterocycle-substituted BODIPY-based fluorescent probes, explored their viscosity-responsive and AIE properties, and further investigated their subcellular localization and viscosity-sensing applications in living cells. Interestingly, the meso-thiazole probe 1 showed both good viscosity-responsive and AIE (in pure water) properties and could successfully target both mitochondria and lysosomes, further imaging cellular viscosity changes by treating lipopolysaccharide and nystatin, attributing to the free rotation and potential dual-organelle targeting ability of the meso-thiazole group. The meso-benzothiophene probe 3 with a saturated sulfur only showed good viscosity-responsive properties in living cells with the aggregation-caused quenching effect and no subcellular localization. The meso-imidazole probe 2 showed the AIE phenomenon without an obvious viscosity-responsive property with a C═N bond, while the meso-benzopyrrole probe 4 displayed fluorescence quenching in polar solvents. Therefore, for the first time, we investigated the structure-property relationships of four meso-five-membered heterocycle-substituted BODIPY-based fluorescent rotors with viscosity-responsive and AIE properties, and among these, 1 with a C═N bond and a saturated sulfur on the meso-thiazole, potentially contributing to their corresponding AIE and viscosity-responsive properties, served as a sensitive AIE fluorescent rotor for imaging dual-organelle viscosity in both mitochondria and lysosomes.

Photocatalytic Co-Reduction of N2 and CO2 with CeO2 Catalyst for Urea Synthesis.

The effective conversion of carbon dioxide (CO2 ) and nitrogen (N2 ) into urea by photocatalytic reaction under mild conditions is considered to be a more environmentally friendly and promising alternative strategies. However, the weak adsorption and activation ability of inert gas on photocatalysts has become the main challenge that hinder the advancement of this technique. Herein, we have successfully established mesoporous CeO2-x nanorods with adjustable oxygen vacancy concentration by heat treatment in Ar/H2 (90 % : 10 %) atmosphere, enhancing the targeted adsorption and activation of N2 and CO2 by introducing oxygen vacancies. Particularly, CeO2 -500 (CeO2 nanorods heated treatment at 500 °C) revealed high photocatalytic activity toward the C-N coupling reaction for urea synthesis with a remarkable urea yield rate of 15.5 µg/h. Besides, both aberration corrected transmission electron microscopy (AC-TEM) and Fourier transform infrared (FT-IR) spectroscopy were used to research the atomic surface structure of CeO2 -500 at high resolution and to monitor the key intermediate precursors generated. The reaction mechanism of photocatalytic C-N coupling was studied in detail by combining Density Functional Theory (DFT) with specific experiments. We hope this work provides important inspiration and guiding significance towards highly efficient photocatalytic synthesis of urea.

Electrochemically Controlled Atom Transfer Radical Polymerization for Electrochemical Aptasensing of Tumor Biomarkers.

Tumor biomarkers are of great value in the liquid biopsy of malignant tumors. In this work, a simple and cost-friendly electrochemical aptasensor was presented for the highly sensitive and selective detection of glycoprotein tumor biomarkers. The DNA aptamer-modified electrode was used as the sensing interface to specifically capture the target glycoprotein tumor biomarkers, to which the alkyl halide initiators for atom transfer radical polymerization (ATRP) were then attached via the esterification crosslinking between the boronic acid group and the cis-dihydroxyl sites of the conjugated oligosaccharide chains on glycoprotein tumor biomarkers followed by the growth of long-chain polymers through electrochemically controlled ATRP (eATRP) to efficiently recruit the ferrocene detection tags. As there are tens to hundreds of cis-dihydroxyl sites on a glycoprotein tumor biomarker for attaching ATRP initiators while each long-chain polymer can recruit hundreds to thousands of ferrocene detection tags, a significantly high current signal can be generated even in the presence of ultralow-abundance targets. Hence, the eATRP-based electrochemical aptasensor is capable of sensitively and selectively detecting glycoprotein tumor biomarkers. Using alpha-fetoprotein as the model target, the limit of detection was demonstrated to be 0.32 pg/mL. Moreover, the aptasensor has been successfully applied to detect glycoprotein tumor biomarkers in human serum samples. In view of its high sensitivity and selectivity, simple operation, and cost-friendliness, the eATRP-based electrochemical aptasensor shows great promise in the glycoprotein-based liquid biopsy of malignant tumors, even at the early stage of development.

Boronate Affinity-Amplified Electrochemical Aptasensing of Lipopolysaccharide.

As lipopolysaccharide (LPS) is closely associated with sepsis and other life-threatening conditions, the point-of-care (POC) detection of LPS is of significant importance to human health. In this work, we illustrate an electrochemical aptasensor for the POC detection of low-abundance LPS by utilizing boronate affinity (BA) as a simple, efficient, and cost-effective amplification strategy. Briefly, the BA-amplified electrochemical aptasensing of LPS involves the tethering of the aptamer receptors and the BA-mediated direct decoration of LPS with redox signal tags. As the polysaccharide chain of LPS contains hundreds of cis-diol sites, the covalent crosslinking between the phenylboronic acid group and cis-diol sites can be harnessed for the site-specific decoration of each LPS with hundreds of redox signal tags, thereby enabling amplified detection. As it involves only a single-step operation (∼15 min), the BA-mediated signal amplification holds the significant advantages of unrivaled simplicity, rapidness, and cost-effectiveness over the conventional nanomaterial- and enzyme-based strategies. The BA-amplified electrochemical aptasensor has been successfully applied to specifically detect LPS within 45 min, with a detection limit of 0.34 pg/mL. Moreover, the clinical utility has been validated based on LPS detection in complex serum samples. As a proof of concept, a portable device has been developed to showcase the potential applicability of the BA-amplified electrochemical LPS aptasensor in the POC testing. In view of its simplicity, rapidness, and cost-effectiveness, the BA-amplified electrochemical LPS aptasensor holds broad application prospects in the POC testing.

Upconversion NaYF4:Yb/Er-TiO2-Ti3C2 Heterostructure-Based Near-Infrared Light-Driven Photoelectrochemical Biosensor for Highly Sensitive and Selective d-Serine Detection.

A near-infrared (NIR) light-driven NaYF4:Yb/Er-TiO2-Ti3C2 (NYF-TiO2-Ti3C2) heterostructure-based photoelectrochemical (PEC) biosensing platform was constructed for highly sensitive d-serine (d-ser) detection. Accurate d-ser detection depends on the model biocatalyst, d-amino acid oxidase (DAAO), which converts d-ser into hydroxypyruvate and an equimolar concentration of hydrogen peroxide (H2O2) via an enzymatic reaction. The TiO2-Ti3C2 semiconductor and NaYF4:Yb/Er optical transducer formed a Schottky junction that provided an irreversible channel for electron transfer. Infrared light was converted into absorbable multiemission light, thereby effectively increasing light absorption. Simultaneously, the generated H2O2 rapidly scavenged photogenerated holes to separate electron-hole pairs, which amplified the photocurrent signal. Under optimal conditions, the NIR light-driven PEC biosensor exhibited an excellent PEC performance for d-ser detection, with a wide linear range of 2-1650 µmol L-1 and detection limit as low as 0.286 µmol L-1. Importantly, high detection reproducibility and accuracy were achieved using this strategy for analyzing human serum and rat cerebrospinal fluid (CSF) specimens. The admirable applicability of the NYF-TiO2-Ti3C2-based PEC biosensor for detecting d-ser may lead to further opportunities for detecting other disease-related biomarkers.

Superhydrophobic Functionalized Ti3C2Tx MXene-Based Skin-Attachable and Wearable Electrochemical pH Sensor for Real-Time Sweat Detection.

Sweat pH is a critical indicator for evaluating human health. With the extensive attention on the wearable and flexible biosensing devices, the technology for the monitoring of human sweat can be realized. In this study, a sensitive, miniaturized, and flexible electrochemical sweat pH sensor was developed for the continuous and real-time monitoring of the hydrogen-ion concentration in human sweat. A flexible electrode was fabricated on the poly(ethylene terephthalate) (PET) substrate by a simple and low-cost screen-printing technology, which was based on the integration of fluoroalkyl silane-functionalized Ti3C2Tx (F-Ti3C2Tx) and the polyaniline (PANI) membrane technology instead of the traditional ion-sensitive membrane. The surface functionalization strategy for Ti3C2Tx with perfluorodecyltrichlorosilane can provide environmental stability. Functionalized Ti3C2Tx (F-Ti3C2Tx) was doped with PANI to obtain improved responsiveness, sensitivity, and reversibility. The constructed microsize, portable, and wearable F-Ti3C2Tx/PANI pH sensor aimed to real-time monitor the pH value of human sweat during exercise. On-body sweat pH monitoring for females and males, respectively, exhibited high accuracy and continuous stability compared with ex situ analyses. This study thus offers a facile and practical solution for developing a highly reliable MXene-based mini-type pH sensor to realize the online monitoring of human sweat pH.

Bismuth Nanoparticles Encapsulated in Nitrogen-Rich Porous Carbon Nanofibers as a High-Performance Anode for Aqueous Alkaline Rechargeable Batteries.

The aqueous alkaline rechargeable batteries (AARBs) have an attractive potential for electrochemical energy storage devices. In view of the advantages of high theoretical capacity and desirable negative operating window, bismuth (Bi) has been deemed as a hopeful anode material for AARBs. Unfortunately, intensive reported works of Bi anode are still confronted with limited capacity and poor cycling stability. Herein, the designed electrodes of different size Bi nanoparticles embedded in porous carbon nanofibers with a contrasting nitrogen doping content are obtained by electrospinning and thermal treatment processes. The effect of the N dopant in carbon shell is demonstrated on the Bi core, which is in favor of enhancing the capacity of Bi anodes. More importantly, the core structure with highly dispersed ultrasmall Bi nanoparticles (<20 nm) in carbon matrix plays a crucial role in long-term durability. Accordingly, the optimized polydisperse ultrasmall Bi nanoparticles confined in N-rich porous carbon nanofibers electrode (Bi@NPCF) presents an admirable capacity of 196.1 mAh g-1 at 3 A g-1 and outstanding durable lifespan (retain 116.95% after 10 000 cycles). In addition, the fabricated Bi@NPCF//NiCo2 O4 battery exhibits an exceptional energy and power density with durable stability (95.9% after 5000 cycles).

Reversible Chiral Optical Switching Based on Co-Assembled Spiropyran Gels.

In recent years, it has been very interesting to dynamically adjust the emission of circularly polarized luminescence (CPL) materials through external stimulation due to their applications and the fundamental interest in them. In this work, luminescence-tunable and light-responsive supramolecular co-assembly CPL-active materials are fabricated by mixing an achiral functional spiropyran (SP-COOH) molecule with a chiral gelator. The spiropyran achieves a reversible change between a white closed ring state spiropyran and a purple zwitterionic merocyanine state in supramolecular co-assembly gels under alternate visible (vis) and ultraviolet (UV) light irradiation. The gel shows strong CPL signals due to the chirality transfer in co-assembly systems. These signals could change reversibly under alternate exposure to UV and vis light. Therefore, utilizing the multistimulus-responsive CPL signals in different states, a CPL switch of the supramolecular system signal according to the combinatorial control of UV-vis light irradiation is constructed.

Review of the formation and influencing factors of food-derived glycated lipids.

Glycated lipids are formed by a Maillard reaction between the aldehyde group of a reducing sugar with the free amino group of an amino-lipid. The formation and accumulation of glycated lipids are closely related to the prognosis of diabetes, vascular disease, and cancer. However, it is not clear whether food-derived glycated lipids pose a direct threat to the human body. In this review, potentially harmful effect, distribution, formation environment and mechanism, and determination and inhibitory methods of glycated lipids are presented. Future research directions for the study of food-derived glycated lipids include: (1) understanding their digestion, absorption, and metabolism in the human body; (2) expanding the available database for associated risk assessment; (3) relating their formation mechanism to food production processes; (4) revealing the formation mechanism of food-derived glycated lipids; (5) developing rapid, reliable, and inexpensive determination methods for the compounds in different foods; and (6) seeking effective inhibitors. This review will contribute to the final control of food-derived glycated lipids.

An electrochemical sensor based on AuPd@FexOy nanozymes for a sensitive and in situ quantitative detection of hydrogen peroxide in real samples.

The hydrogen peroxide (H2O2) levels in living organisms and environment have strong effects on many biological processes inducing cell apoptosis/cell necrosis and wound disinfection. Therefore, it is important to have an accurate and in situ detection of H2O2. Herein, an AuPd@FexOy nanozyme-based electrochemical (EC) sensor (termed as AuPd@FexOy NPs/GCE) with good stability and anti-interference ability has been prepared for the detection of H2O2 by differential pulse voltammetry (DPV) and chronoamperometry dual-measurement modes. The AuPd@FexOy NPs/GCE exhibits good linear relationships in the ranges from 13.0 to 6.0 × 103 µM (DPV measurement) and 50 to 1.0 × 103 µM (chronoamperometry measurement), low detection limits (LODs) of 1.6 µM (DPV measurement) and 3.0 µM (chronoamperometry measurement) and high sensitivities of 83.8 nA µM-1 cm-2 (DPV measurement) and 120.7 nA µM-1 cm-2 (chronoamperometry measurement). The practicability of the as-prepared AuPd@FexOy NPs/GCE has been demonstrated by an in situ real-time detection of H2O2 released from adherent living MCF-7 cells triggered by varying amounts of N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) from 0.5 to 3.0 µM and the quantitative determination of H2O2 in commercial disinfectants.

Polydopamine-based molecularly imprinted electrochemical sensor for the highly selective determination of ecstasy components.

3,4-Methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) are the main components of illicit stimulant drugs, also known as "ecstasy", which belong to psychoactive medicine and tend to be increasingly abused among drug addicts worldwide. Herein, an electrochemical sensor based on molecularly imprinted polydopamine (MIP@PDA) was developed to detect MDA and MDMA using differential pulse voltammetry (DPV). An MIP film on a Au electrode was synthesized via electrochemical polymerization with the safe chemical DA as the polymerization monomer and the uncontrolled pharmaceutical intermediate 3,4-methylenedioxyphenethylamine (MDPEA) as the template molecule, which can provide a great quantity of specific binding sites and expand the practical application of the sensor. Due to the superior affinity of MIP@PDA to the target, the proposed sensor displayed excellent analytical performance, with LODs of 37 nM and 54 nM for the determination of MDA and MDMA, respectively. Additionally, this sensor presented suitable selectivity, stability, reproducibility and detection ability in practical urine samples, which suggested that it is a promising candidate as a rapid diagnostic method in drug investigations.