A dual-signal lateral flow immunoassay (LFIA) was developed utilizing gold–platinum core–shell nanoparticles (Au@Pt NPs) for ultrasensitive cardiac troponin I (cTnI) detection. Owing to the synergistic electronic effects between the Au core and dendritic Pt shell, the Au@Pt NPs exhibit both high peroxidase-mimetic activity and a strong near-infrared photothermal effect. This allows for integrated colorimetric amplification and photothermal signal transduction within a single strip format. Under optimized conditions, the assay achieved a visual detection limit of 0.1 ng·mL⁻¹. Quantitative colorimetric determination yield limits of detection (LOD) of 0.044 ng·mL⁻¹ in PBS and 0.051 ng·mL⁻¹ in serum. Notably, the photothermal mode demonstrated exceptional matrix resilience, maintaining nearly identical LODs in PBS (0.036 ng·mL⁻¹) and serum (0.037 ng·mL⁻¹) over a linear range of 0.1–10 ng·mL⁻¹. This matrix-resilient performance is attributed to the thermophysical confinement effect of the biological matrix, which enhances the sensitivity slope in complex media. Overall, the proposed dual-mode LFIA provides a robust, pretreatment-free diagnostic tool that combines rapid visual screening with precise quantitative analysis, supporting early, point-of-care assessment of myocardial injury.

Kanamycin (KANA) residues pose potential risks to human health and the environment, creating an urgent need for rapid, sensitive, and simple monitoring methods. Herein, a dual-signal-amplified electrochemical aptasensor was developed for trace KANA detection in milk by integrating cobalt-embedded nitrogen-doped carbon (Co-NC) derived from ZIF-67 with an entropy-driven strand displacement reaction (ESDR). The dodecahedral Co-NC features abundant active sites and a porous structure, facilitating electron transfer and efficient loading of the capture strand. Upon KANA binding, the released complementary DNA initiates the ESDR, resulting in the generation of numerous signal strands and significant electrochemical signal amplification. The proposed aptasensor exhibits a wide linear range (10 fg/mL–100 ng/mL), an ultralow detection limit (9.08 fg/mL, S/N = 3), and satisfactory recoveries (96.54%–105.79%). This strategy provides a reliable and promising platform for sensitive KANA residue detection in food samples.

Thiram residues are routinely monitored in agricultural products because of their relevance to pesticide safety. Fluorescence sensing is well suited to this task, but most reported sensors depend on toxic metal ions and are confined to liquid systems. Here, Cd-free Mn@ZnS QDs were used as the fluorescent indicator in a hydrogel designed for portable thiram detection. The QDs emitted bright red fluorescence and responded to thiram without additional metal ions. This response arose from target-induced aggregation of the Mn@ZnS QDs together with activation of photoinduced electron transfer. Embedding the QDs in agarose produced the Mn@ZnS@AG hydrogel, whose fluorescence weakened progressively as the amount of thiram increased. Hydrogel images were resolved into RGB values, and the R/B ratio served as the quantitative output. The assay reached a limit of detection (LOD) of 0.27 μM and completed the detection in 49 s, the shortest time reported for a solid-phase thiram assay. The Cd-free QD/agarose design thus provides a distinct route toward improved practical applicability and offers a portable platform for monitoring thiram-related food safety.

Methylated septin9 (septin9-mC) is a well-validated biomarker for colorectal cancer screening, and accurate detection of such site-specific methylated DNA holds significant clinical value for early disease diagnosis. However, conventional methods suffer from cumbersome pretreatment, DNA degradation risks, and poor performance in low-abundance samples. Herein, we report a synergistic iontronic sensing platform integrating methylation-sensitive restriction enzyme (AciI), CRISPR/Cas12a, Ag-DNAzyme, and Au/Pt heterometallic nanozyme for highly sensitive and specific detection of septin9-mC. AciI selectively cleaves unmethylated septin9 (septin9-C) while sparing septin9-mC, and intact septin9-mC activates Cas12a trans-cleavage activity to trigger catalytic hairpin assembly (CHA), generating Ag-DNAzyme. Activated Ag-DNAzyme induces detachment of Au/Pt nanoparticles from anodic aluminum oxide membranes, reducing the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to positively charged oxTMB and altering ion transport fluxes in nanochannels, which is read out via current-voltage characteristics. The linear range is 100 aM to 10 nM with a detection limit of 34.0 aM. This method effectively distinguishing colorectal cancer cells from human colonic epithelial cells and colorectal cancer patients from healthy individuals, showing excellent performance in real sample analysis. The proposed method provides a dependable tool for site-specific methylation detection with promising applications in biological research and clinical diagnosis.

Fluorescence hydrogels have become attractive candidates for monitoring food freshness; however, the ability to improve anti-interference, broaden the color variation range, and introduce multifunctionality remains limited. Here, an ingenious fluorescence hydrogel design strategy for monitoring food freshness is proposed via integrating an OH--responsive dye into functional matrices. By adjusting the intermolecular charge transfer and π-π stacking effect, nitrobenzoxadiazaole-based dye BOD-R1 was prepared and responded to biogenic amines via nucleophilic substitution. Embedding BOD-R1 in benzene-1,4-diboronic acid, poly(vinyl alcohol) (PVA), agarose (AG), and carboxymethyl cellulose (CMC) produced hydrogel R1@BAPC, which exhibited antifreezing ability, self-repairing function, high adhesion, and interface self-adaptability. Notably, the fluorescence color of R1@BAPC progressively changed from blue to yellow, as the amount of target putrescine (Put) increased, and then extracted into RGB values, in which G/B acted as the quantitative output. The hydrogel achieved a limit of detection (LOD) of 0.26 ppm for Put and completed detection within 85 s. Real sample analyses with shrimp, chicken, and pork suggested that the test results aligned well with those of the standard method, supporting excellent practical usability. The BOD-R1/BAPC design not only provides a distinct route for the synthesis of multifunctional hydrogels but also provides a portable platform for monitoring food freshness, with potential benefits for healthy food supply.

Hydrogenation of 1,3-dimethyl-5-nitroso-6-aminouracil (2Me-NAU) to 1,3-dimethyl-5,6-diaminouracil (2Me-DAU) is a pivotal step in xanthine drug synthesis. Residual acidic impurities from the preceding nitrosation step in dilute sulfuric acid severely deactivate conventional Raney nickel catalyst, causing rapid efficiency decay. To address this, for the first time, we developed an acid-resistant porous carbon-coated nickel phosphide catalyst (Ni2P@C) that effectively prevents Ni leaching during 2Me-NAU hydrogenation, superior to the Reney nickel catalyst. This catalyst achieves a remarkable 97.4 % 2Me-DAU yield under industrially relevant conditions. Comprehensive characterization confirms that an optimally thick carbon shell combined with controlled defect density maintains both high catalytic activity and exceptional stability (>18 cycles in pH 3.05 H2SO4), demonstrating its superior acid resistance as well as potential for large-scale application. This work provides a reference for designing acid-resistant non-noble metal catalysts and offers impetus for the green synthesis of xanthine drugs.

Myoglobin (Myo) is an early-rising biomarker of acute myocardial infarction, yet rapid quantitative point-of-care testing remains challenging for conventional colorimetric lateral flow immunoassays (LFIAs) because of limited sensitivity and background-dependent interpretation. Here, we report a dual-mode colorimetric/photothermal (CM/PT) LFIA enabled by one-pot synthesized gold nanocages (GNCs) with a localized surface plasmon resonance (LSPR) band positioned near the 808 nm excitation window. The GNCs showed high PT conversion efficiency (42.59%) and were electrostatically assembled with anti-Myo monoclonal antibodies to form stable immunoprobes. A premixing workflow was used to standardize antigen-probe complex formation, enabling visual screening and temperature-contrast (Delta T)-based thermometric quantification on the same test strip. In phosphate-buffered saline (PBS), the calculated limits of detection (cLODs) were 0.61 ng center dot mL- 1 for the CM readout (T/C) and 0.26 ng center dot mL- 1 for the PT readout, confirming the sensitivity advantage of thermometric transduction. In spiked serum matrix, the PT mode retained a cLOD of 0.41 ng center dot mL- 1, and the response remained monotonic within the validated range of 0-500 ng center dot mL- 1. The assay showed high selectivity against creatine kinase-MB (CK-MB), cardiac troponin I (cTnI), C-reactive protein (CRP), and procalcitonin (PCT), acceptable intra-/inter-batch precision, reliable serum recovery, and one-month storage stability. Overall, this work provides a practical route for integrating PT quantification into standard LFIA formats without altering strip architecture and is potentially extendable to other cardiac or inflammatory biomarkers by substituting antibody pairs.

Procalcitonin (PCT) is a clinically important biomarker for bacterial infections and sepsis, motivating rapid and sensitive point-of-care quantification. Herein, a colorimetric-fluorescence dual-mode lateral flow immunoassay (LFIA) was developed by integrating gold nanoparticles (AuNPs) and arginine/6-Aza-2-thiothymine-stabilized gold nanoclusters (ATT-Arg-AuNCs). AuNPs conjugated with detection antibodies served as colorimetric reporters, while AuNCs associated with capture antibodies formed an immobilized fluorescent donor layer on the test line. Upon PCT-mediated sandwich assembly, AuNP enrichment intensified the colorimetric band and simultaneously imposed nanoscale AuNP-AuNC co-localization, activating metal-induced nonradiative dissipation and proximity-regulated fluorescence quenching (intrinsically coupled "color-on/fluorescence-off" transduction). Under optimized conditions, the colorimetric mode (T/C) exhibited a linear response over 0.5-10 ng mL(-1) with a limit of detection (LOD) of 0.079 ng mL(-1), whereas the fluorescence mode (Delta F) provided a wider linear range of 0.05-10 ng mL(-1) with a lower LOD of 0.006 ng mL(-1). In spiked serum samples (n = 3), recoveries were 95.1%-105.1% (colorimetric) and 92.3%-116.4% (fluorescence), with relative standard deviations <10%, demonstrating acceptable accuracy and precision in complex matrices. This intrinsically coupled dual-mode LFIA combines visual screening with sensitive quantification in a single strip and offers a generalizable strategy for extending proximity-gated dual-readout LFIAs to other biomarkers via antibody substitution.

In this work, a highly sensitive lateral flow immunoassay (LFIA) strip based on luminescent green-emitting gold nanoclusters (AuNCs) was developed for ultrasensitive and facile visual determination of imidacloprid (ICP). Specifically, the structurally ordered AuNCs system, constructed through 6-aza-2-thiothymine (ATT) as the coordinating ligand and L-arginine (Arg) as the guest molecule (denoted as Arg/ATT/AuNCs), exhibited enhanced and persistent fluorescent emission characteristics. Furthermore, the presence of unbound carboxyl moieties on the Arg/ATT/AuNCs complex facilitated the conjugation with biomolecules, thereby providing a functional indicator for the biosensor assembly. The developed strips operate on the principle of an indirect competitive assay and are capable of effectively detecting target samples in less than 12 min. Moreover, the sample only needs to undergo simple crushing and filtration. The assay provides qualitative results through visual inspection under a UV lamp and quantitative analysis via a portable fluorescence reader. The visual limit of detection (vLOD) was 7.5 ng/mL and the limit of detection (LOD) is 0.026 ng/mL. Additionally, the average recoveries of ICP from apples, oranges, cucumbers, and cabbages samples ranged from 78.0

BACKGROUND:In the contemporary era of rapid digital advancement, information security is closely associated with our daily life. From personal information to state secrets, all domains are intricately linked with information. Consequently, the significance of information security has garnered growing attention from an ever-increasing number of individuals. However, single-level anti-counterfeiting materials are susceptible to being copied and counterfeited, which may result in the destruction, alteration, or leakage of information, so developing low-cost and highly secure multilevel anti-counterfeiting materials still poses a significant challenge. RESULTS:We constructed dual-emission center ratiometric fluorescence probes AP-CDs by simple mixing blue-emitting carbon dots (AB-CDs) and red-emitting carbon dots (PT-CDs), for information encryption and detection of Cu(Ⅱ) and Cr(Ⅵ). The detecting mechanism for Cu(Ⅱ) involved static quenching (SQ) and aggregation-caused quenching (ACQ), whereas for Cr(Ⅵ) was dynamic quenching (DQ) and inner filter effect (IFE). The established sensors had similar accuracy to that of the atomic absorption spectrophotometry in the Chinese national standard method, and had been employed to detect Cu(Ⅱ) and Cr(Ⅵ) in the actual samples with satisfactory results. Meanwhile, platform utilizing smartphones and test paper for Cu(Ⅱ) detection had been developed to enable visual analysis on-site. Furthermore, the anti-counterfeiting efficacy of the AP-CDs as fluorescent inks was verified by taking advantage of the color change of AP-CDs before and after the reaction with Cu(Ⅱ), and combining the color differences of commercially available fluorescent ink (CAFI) under different excitation wavelengths. SIGNIFICANCE AND NOVELTY:AP-CDs was able to specifically recognize Cu(Ⅱ) and Cr(Ⅵ) with excellent selectivity, sensitivity and practicality. Additionally, AP-CDs successfully achieved the requirements for basic, dual, and multi-level anti-counterfeiting measures, thereby addressing a wide range of anti-counterfeiting needs. Consequently, this strategy offers a green and cost-effective approach for the synthesis of CDs endowed with Cu(Ⅱ) and Cr(Ⅵ) sensing capabilities as well as anti-counterfeiting functionalities, which has potential application prospects in the fields of sensors and anti-counterfeiting.

BACKGROUND:Antibiotics have been extensively applied to treat human and animal diseases for a long time, leading to residues in the environment and food. As a major global concern, there is an urgent need for sensitive, and easy-to-use detection techniques for antibiotics. The efficient extraction and enrichment of quinolone antibiotics in complex samples still subject to some limitations. Microporous organic networks (MONs) have received widespread attention as adsorbents for sample pretreatment. However, the design and synthesis of functionalized MONs to obtain superior performance still need to be developed. RESULTS:In this study, a magnetic functionalized triazine based-microporous organic network (Fe3O4@TMON) was synthesized for the extraction, purification, and detection of quinolone antibiotics in water and meat samples. Batch experiments, chemical characterization, and simulation calculations illustrated the good adsorption performance of Fe3O4@TMON for ofloxacin (OFL), ciprofloxacin (CIP), and enrofloxacin (ENR). π-π stacking, π-π EDA, hydrogen bonding, and hydrophobic interactions dominate the adsorption process. A novel method for detecting quinolones in water and meat samples using high-performance liquid chromatography with fluorescence detector was established under optimized magnetic micro-solid phase extraction parameters based on Fe3O4@TMON. For water samples, the enrichment factors, limits of detection, recoveries, and precisions were within the ranges of 215.8-265.0, 0.20-0.40 ng/L, 86.3-106.0 %, and 2.9-7.9 %, respectively. And for meat samples, they were 8.7-9.9, 0.08-0.16 μg/kg, 87.2-98.8 %, and 2.9-8.6 %, respectively. SIGNIFICANCE:This work developed a new member of MONs, exhibiting good application potential in the efficient extraction of organic pollutants from complex matrices. It provides a new perspective and reference for the formation of detection strategies, establishment of detection methods, and exploration of adsorption mechanisms. In addition, it ensures environmental safety and human health, laying a solid foundation for future scientific research and technological development.

Currently, the overuse of antibiotics has led to the widespread dissemination of multidrug‐resistant bacteria, making the development of novel antimicrobial agents an urgent scientific challenge. 0D fluorescent nanomaterials (including carbon quantum dots, semiconductor quantum dots, and metal nanoclusters) exhibit outstanding antibacterial performance due to their unique nanoscale size effects, excellent biocompatibility, and remarkable surface‐area effects, positioning them as a promising solution against multidrug‐resistant bacterial infections. This review systematically summarizes the synthesis strategies and characteristic properties of these materials, with a focus on their antimicrobial applications in medical and health care, the food industry, agriculture, and industry. Furthermore, the advantages and current technical limitations of these emerging antimicrobial agents are critically discussed. The aim of this review is to provide a theoretical foundation for the rational design and development of nanoantibacterial materials while facilitating their translational applications in biomedicine.

Bacterial pathogens are the primary causes of foodborne diseases, so sensitive and reliable pathogen detection is becoming increasingly important for human health and safety. This study reports a nanopore biosensing platform based on an aptamer self-assembly electrochemical/fluorescent dual-signal amplification strategy for sensitive detection of pathogenic bacteria. The dual-signal nanopore platform uses bacterial aptamers as specific recognition elements and constructs DNA superstructures in combination with fluorescent probes. When the target bacteria are introduced into the system, the DNA superstructures undergoes specific dissociation, forming an aptamer-bacteria complex on the nanopore surface while releasing fluorescent probes into the solution. This process elicits a synergistic response of current signal attenuation and fluorescent signal enhancement. The proposed sensor exhibits a broad dynamic detection range for E. coli and S. aureus. In the electrochemical detection mode, it demonstrates high recognition sensitivity for low-concentration bacteria. The detection limits for E. coli and S. aureus are as low as 7.99 cfu/mL and 5.76 cfu/mL, respectively. In the fluorescence detection mode, the detection limits for the two bacteria are 58.88 cfu/mL and 75.86 cfu/mL, respectively. The detection performance of the sensor in actual samples was verified by spiked recovery experiments, and the results showed good consistency with the standard culture method. This fully demonstrates its stable and reliable detection capability in complex matrix environments, providing effective technical support for microbial detection in various scenarios.

In this study, zeolite imidazolate framework (ZIF-67) was used as a cobalt source, and Co3O4 hollow cubes were obtained after air carbonization. Nickel-iron layered double hydroxides (NiFe-LDH) were subsequently synthesized on the Co3O4 hollow cubes using an oil bath method to produce the final material for nitrobenzene (NB) detection. The hollow-cube structure not only provides more active sites and increases surface area but also offers numerous channels for ion and electron transfer, thereby enhancing charge transfer and improving sensing performance. The incorporation of NiFe-LDH further amplifies the synergistic catalytic effect between the transition metals, with each metal playing a distinct role in achieving a coordinated catalytic effect. Under optimized conditions, the composite exhibits a wide linear range (1.5-1765.5 mu M) and the limit of detection of 0.162 mu M. Additionally, it demonstrates anti-interference, stability, and reproducibility, offering an effective method for trace detection of NB in environmental samples.

Pursuing cost-effective non-precious metal electrocatalysts is a key challenge in the field of sustainable energy conversion. Transition metal dichalcogenides, known for their unique electronic structure, demonstrate superior electrocatalytic capabilities for the hydrogen evolution reaction (HER), yet their effectiveness is still lacking. In the present study, a CuS/Co3S4@MWCNT composite was fabricated via single-step hydrothermal synthesis for HER applications. This catalyst exploited the synergistic effects between CuS and Co3S4 to increase edge site functionalities and metallic conductivity, thereby resulting in high catalytical activity within the material. Furthermore, the incorporation of multi-walled carbon nanotubes (MWCNTs) into the composite effectively enhanced electron transfer kinetics throughout the HER process. Notably, thiourea serves a dual function in this synthesis, acting both as a reducing agent and as a sulfur source for the formation of metal sulfides. When evaluated in a 1 M KOH alkaline electrolyte, the synthesized nanocomposite exhibited a minimal overpotential of 300 mV to reach a current density of 10 mA/cm2, and a Tafel slope of merely 76.2 mV/dec, indicative of its good HER catalytic activity. These findings underscore the composite’s potential for application in hydrogen production technologies.

Pursuing nanomaterials with high fluorescence quantum yields is of great significance in the fields of bioimaging, medical diagnosis, and food safety monitoring. This work reports on orange-emitting aggregation-induced emission (AIE) copper nanoclusters (Cu NCs) integrated with blue-emitting nitrogen-doped carbon dots (N-CDs), which enables highly sensitive detection of S2- and Zn2+ ions through an off-on ratiometric fluorescence method. The highly emissive Cu NCs was doped by Ce3+ with a high quantum yield of 51.30 % in aqueous solution. The S2- can induce fluorescence quenching of AIE Cu NCs/N-CDs from orange to blue, while Zn2+ can restore the orange fluorescence. The probe provided linear detection ranges of 0.5-170 μM for S2- and 0.05-200 μM for Zn2+, with detection limits of 0.17 μM and 0.02 μM, respectively. Moreover, a smartphone assistant ratiometric fluorescent test strips were developed for the rapid and visual detection of S2- and Zn2+. The AIE Cu NCs/N-CDs probe exhibited diverse fluorescence color responses, high fluorescence stability, and low cytotoxicity. The ratiometric system was successfully applied to the detection of S2- and Zn2+ in real water samples as well as in cellular and living imaging, demonstrating its potential in biochemical analysis and food safety monitoring.

In this study, a simple one-pot method was employed to synthesize an iron-nickel-carbon composite material. Glucose-derived mesoporous carbon spheres (CS) were used as a template, while urea served as a linking agent. Well-defined iron-nickel nanoparticles (Fe-Ni NPs) were incorporated into the CS to form a passion fruit-shaped structure. The resulting FeNi/CS catalyst exhibits excellent synergistic effects, effectively promoting electron transfer and charge migration. This composite material also demonstrates outstanding electrocatalytic performance for detecting nitrobenzene (NB). The results show a wide detection linear range from 1 to 1000 mu M, with a low detection limit of 0.12 mu M, as well as good anti-interference capability and high sensitivity. Furthermore, NB monitoring in real water samples yields satisfactory recovery rates ranging from 97.18 % to 102.75 %. The unique electrochemical sensor offers a novel approach for NB detection.

In this study, a Co doped polyhedral carbon skeleton (Co CN) was prepared by nitrogen carbonization using ZIF67 as a precursor. The Co CN features a rough surface with excellent electrical conductivity, and the Co atoms exhibit unique catalytic properties. Based on these characteristics, we used Co CN as a carrier to load Au nanoparticles (NPs) onto its surface through the linkage and reduction effects of polyoxometalates (POMs). The resulting Au/POM/Co CN three-component composite nanoparticles exhibited exceptional performance in dopamine detection, showing a reliable linear response within the concentration ranges of 0.4-58 mu M and 58-298 mu M, with a limit of detection (LOD) as low as 0.198 mu M. Additionally, the sensor showed excellent stability, anti-interference properties, and high recovery in experimental tests. This approach provides a novel concept for bimetallic catalysis and expands possibilities for dopamine detection.

This paper presents the synthesis of a novel corn-stalk-like MnO2/CoNi oxide composite using an in situ epitaxial attachment growth strategy, in which CoNi oxide nanosheets are anchored onto MnO2 nanowires. The onedimensional MnO2 nanowires, with their large specific surface area, serve as a support to enhance the electronic conductivity of the CoNi oxides. Hexamethylenetetramine (HMTA) is employed as an alkaline linking agent, playing a key role in shaping the CoNi oxide nanosheets and ensuring their successful growth on the MnO2 nanowires. The MnO2/CoNi oxide composite-based electrochemical sensor exhibits excellent synergistic and interfacial effects, promoting electron transfer and charge migration. This composite material shows outstanding electrocatalytic performance for hydrazine detection, with a broad linear range (0.48-6106.58 mu M), low detection limit (0.286 mu M, S/N = 3), and high sensitivity (0.037 mu A mu M-1). Moreover, when tested for hydrazine detection in water samples, the sensor achieved a recovery rate of 95.7-105 %, highlighting its high sensitivity and rapid response in practical applications.

CoFe-based catalysts are efficient electrocatalysts for the oxygen evolution reaction (OER) in alkaline media. Here, we present a simple one-pot hydrothermal method for synthesizing a series of CoFe glycerates with controllable surface morphologies and investigate their potential as highly efficient catalysts for the OER in alkaline media. These CoFe glycerates exhibit a unique yolk-shell microsphere structure assembled from ultra- thin nanosheets. The adjustment of the surface nanosheet size is achieved by varying the CoFe ratio, ensuring a more efficient electrocatalytic system for the OER process. Due to the abundant active sites provided by the yolk- shell structure and interleaved ultrathin nanosheets, Co3Fe1 glycerate (Co3Fe1 gly) demonstrates a low over- potential (283 mV) and a small Tafel slope (44.61 mV dec-1) at 10 mA cm- 2. Additionally, Co3Fe1 gly exhibits excellent durability in alkaline electrolytes. Moreover, a series of characterizations demonstrate that the active sites of Co3Fe1 gly are the high-valence Co species generated during the OER process. This study opens a promising avenue for utilizing efficient and low-cost electrocatalysts to enhance OER performance.