Harmful cyanobacteria are capable of producing hepatotoxic microcystins (MCs), which pose a significant risk to both aquatic ecosystems and public health. Since cyanobacterial strains that produce MCs harbor the mcy gene cluster, monitoring and analyzing the levels of the mcy gene is critical for identifying potential MCs-producing strains and assessing periods of elevated risk. In this study, Fe single-atom nanozymes (Fe SANs) with enhanced peroxidase-like (POD) activity were synthesized, which were then used to form a Fe SANs-DNA-magnetic bead complex (Fe SANs-DNA-MB). By integrating pre-amplification via recombinase polymerase amplification (RPA), trans-cleavage by CRISPR/Cas12a, and catalytic activity by Fe SANs, a novel triple signal amplification biosensor was developed for the detection of the microcystin synthase gene E (mcyE), a critical biomarker for MCs-producing cyanobacteria. The biosensor demonstrated significantly improved analytical performance, achieving a broad dynamic rangefor mcyE detection from 0.1 pM to 20 nM (R2 = 0.99), with a low limit of detection (LOD) of 0.05 pM. Furthermore, the biosensor provides high accuracy, as evidenced by spiked recoveries of mcyE in natural lake water samples ranging from 97.93

Salmonella is a widely distributed foodborne pathogen that poses a serious threat to public health. Traditional detection methods suffer from limitations such as being time-consuming, complex, and reliant on expensive equipment, making them unsuitable for rapid and on-site detection. In recent years, nanomaterial-based optical biosensors have emerged as a research hotspot in Salmonella detection due to their high sensitivity, strong specificity, fast response, and portability. These sensors offer new technological approaches for real-time monitoring and early warning of pathogens. This paper reviews the research progress of nanomaterial-based optical biosensors for Salmonella detection over the past five years, systematically summarizing the design principles, performance characteristics, and applications of different biorecognition elements and optical signal components in Salmonella detection. It also highlights the selection and integrated design strategies of combining different biorecognition elements with optical signal components to improve detection sensitivity, shorten detection time, and enhance specificity, providing a theoretical reference for researchers in this field. Finally, the paper analyzes the strengths and weaknesses of current technologies and discusses future development directions of nanomaterial-based optical biosensors for Salmonella detection, aiming to advance the technology and provide more efficient and reliable solutions for public health security.

Microcystis aeruginosa (M. aeruginosa) and the associated release of microcystin-LR (MC-LR) pose significant threats to aquatic ecosystems and public health. This study reported the one-pot synthesis of a magnetically recyclable Fe3O4-embedded iron single-atom nanozyme (Fe3O4@Fe SAN) from Fe3O4@ZIF-8. The Fe3O4@Fe SAN exhibited multi-enzyme mimetic activity and activated peroxymonosulfate (PMS), generating a variety of reactive oxygen species (ROS) including hydroxyl radicals (& centerdot;OH), singlet oxygen (O-1(2)), superoxide radicals (O-2(& centerdot;-)) and sulfate radicals (SO4 & centerdot;-). In the presence of PMS, the Fe3O4@Fe SAN achieved >90% inactivation rate of M. aeruginosa (1.7-2.2 & times; 10(7) cells/mL) within 5 min, with a highest rate constant (K-obs) of 1.444 min(-0.4), calculated by the Chick-Watson-Hom (Hom) model. Similarly, an 85% degradation rate of MC-LR (8-14 mu g/mL) was achieved within 20 min, and the maximum pseudo-first-order exponential decay rate constant (K-obs) reached 3.334 min(-1).The cell disruption and MC-LR degradation were attributed to the ROS generation from both the Fe3O4@Fe SAN and PMS activation. The MC-LR degradation pathways were elucidated using HPLC-MS analysis and density functional theory calculations, and toxicity assessment indicated significantly reduced cytotoxicity of the degradation products. Owing to its high catalytic efficiency, facile magnetic separation, and acceptable reusability, the Fe3O4@Fe SAN-PMS system shows promising potential for application in cyanobacterial bloom control and environmental remediation.

Recent advancements in microfluidic paper-based analytical devices (μPADs) have demonstrated their significant potential for point-of-care testing (POCT), particularly in low-resource settings. These devices are especially promising for monitoring glucose levels in patients with diabetes, offering a cost-effective and portable solution. However, one of the primary challenges hindering the widespread adoption of smartphone-coupled μPADs has been their sensitivity to varying ambient lighting conditions, which can interfere with accurate colorimetric detection. To address this issue, researchers have introduced a novel approach involving a metal-organic framework (MOF), specifically Co-TCPP (Fe) [cobalt Fe-(III) meso-tetra-(4-carboxyphenyl) porphyrin chloride], synthesized using a straightforward method. Co-TCPP (Fe) exhibits remarkable peroxidase-like activity when exposed to hydrogen peroxide (H2O2), enabling it to interact effectively with classic chromogenic substrates and thus improving the colorimetric reaction crucial for accurate glucose detection. In this study, the team developed paper-based μPADs that incorporate the Co-TCPP (Fe) MOF, allowing it to accurately detect glucose levels across a wide concentration range. The limit of detection (LOD) achieved was 5.3 μM, with a linear detection range from 5 to 750 μM. This innovation addresses previous concerns regarding the impact of environmental lighting fluctuations and varying shooting angles, ensuring the reliability of glucose measurements under uncontrolled conditions. By integrating this algorithm into a smartphone-coupled μPAD system, the researchers have created a portable, high-resolution platform that delivers dependable results, even in challenging and fluctuating environments. This breakthrough marks a significant step toward enhancing the practicality and accessibility of glucose monitoring in resource-constrained settings, providing a valuable tool for both clinical and everyday use.

Alpha-fetoprotein (AFP) is a critical tumor biomarker associated with various diseases, and its accurate determination is very important for clinical detection. However, the conventional techniques for detecting AFP have drawbacks such as complex sample pretreatment procedures, complicated and time-consuming operations, reliance on expensive and bulky instruments, and the need for skilled professionals, thus limiting their applications. The emergence of aptamers provides a novel and unique probe for establishment of aptasensors, effectively avoiding the aforementioned shortcomings. As a result, the application of aptamers for AFP detection has garnered increasing attention and became one of the research hotspots in recent years. In this review, the progress of aptamer selection against AFP is presented initially. Subsequently, we systematically summarize the latest advancements and trends in optical and electrochemical aptasensors for AFP detection, focusing on known AFP aptamer sequences and methods that use aptamers, such as fluorescence, surface-enhanced Raman scattering (SERS), chemiluminescence (CL), and photoelectrochemistry (PEC). In addition, challenges and future directions in this field are discussed to provide insights for the development of efficient and accurate AFP detection technologies.

Pomegranate (Punica granatum) peel is a rich source of polyphenols with recognized bioactivities. This study evaluated the quorum sensing (QS)-inhibitory and anti-biofilm properties of a standardized pomegranate extract, as well as its major ellagitannins (punicalagin and ellagic acid), against Pseudomonas aeruginosa, an important opportunistic pathogen associated with multidrug-resistant infections. Using the P. aeruginosa strain (ATCC 27853) and the QS biosensor Chromobacterium violaceum, the pomegranate extract and punicalagin (MIC = 0.5 and 0.1 mg/mL, respectively) suppressed the production of QS-regulated virulence factors (pyocyanin >80%, rhamnolipids >60%), inhibited bacterial motility, and disrupted biofilm formation (>70%) without inducing resistance. Cytotoxicity assays demonstrated the favorable cytocompatibility of the extract in mammalian cells. To enable localized delivery, a mechanically robust polyvinyl alcohol-chitosan (PVA-CS) hydrogel was developed. Structural characterization revealed a porous, hydrogen-bond-stabilized structure with enhanced thermal stability, favorable swelling behavior, and excellent moisture retention. Under simulated infection conditions, the extract-loaded hydrogel (P3C2P) significantly inhibited bacterial growth, attenuated virulence production, and suppressed both motility and biofilm formation. These findings demonstrate a triple-action anti-infective mechanism-mediated by punicalagin, which concurrently targets virulence, motility, and biofilm formation. This work establishes a natural product-based hydrogel platform with significant translational potential for wound management and antimicrobial applications.

The detection and degradation of antibiotic residues, as well as the elimination of pathogenic bacteria from medical sewage, are critical for ensuring public health safety. Herein, copper-manganese nanoparticles (CM) exhibiting strong fluorescence characteristics, excellent peroxidase (POD)-like activity, and exceptionally high photothermal conversion efficiency were synthesized using copper gluconate (Glu-Cu), manganese gluconate (Glu-Mn), and folic acid (FA) as precursors. The interaction between oxytetracycline (OTC) and the surface of CM nanoparticles induced nanoparticle aggregation, leading to fluorescence quenching via a static quenching mechanism. Simultaneously, the weak reducing capacity of OTC and its inhibitory effect on the POD-like activity of CM facilitated its colorimetric detection. Under photothermal conditions, the POD-like activity of CM was significantly enhanced, resulting in an efficient degradation of OTC, achieving a removal rate of 89.4 % within 60 min. Owing to the photothermal-enhanced POD-like activity, the CM nanoparticles also demonstrated potent antibacterial performance, achieving an antibacterial efficiency of up to 95.37 %. This work presents the innovative develoment of CM nanoparticles with multi-functionality, enabling both sensitive detection and effective degradation of OTC, as well as antibacterial action, thus demonstrating promising potential for integrated monitoring and remediation of antibiotic contamination in medical sewage.

The widespread presence of antibiotic residues in the environment and food represents a significant threat to human health. In this study, a novel MOF-on-MOF (FCZE) gel with excellent peroxidase activity and strong fluorescence properties successfully synthesized by using Polyvinyl pyrrolidone (PVP) as a cross-linker and H4BTEC as a ligand. Based on the energy transfer from the FCZE ligand to Eu luminescence, an ultrasensitive fluorescence method was developed for the detection of chlortetracycline (CTC), achieving a limit of detection (LOD) as low as 0.43 nM. Furthermore, the combination of FCZE with the 3,3 ',5,5 '-tetramethylbenzidine (TMB)hydrogen peroxide (H2O2) system enabled sensitive colorimetric detection of D-penicillamine (D-PA) with an LOD of 8.66 nM. Theoretical calculations reveal that the fluorescence quenching of FCZE by CTC is attributed to the inner filter effect of CTC and its suppression of the H4BTEC excited-state return to the ground state. Furthermore, Fukui function was employed for the first time to clarify the role of D-PA in scavenging free radicals and reducing oxidized TMB (oxTMB), providing a comprehensive understanding of the colorimetric detection mechanism. Additionally, a smartphone-assisted visual detection platform based on FCZE was developed for the detection of CTC and D-PA, with LODs of 0.71 mu M and 0.13 mu M, respectively. This study highlights the potential of nanomaterials for the simultaneous detection of multiple antibiotics, offering a novel strategy for the rapid and efficient monitoring of antibiotic residues in environmental samples.

Ciprofloxacin (CIP) residues in environmental and food matrices lead to potential public health and safety issues, necessitating the development of a sensing platform for ultra-sensitive detection of CIP residues to achieve rapid on-site detection. Here, a high-performance fluorescence sensing platform based on Eu3+-functionalized metal-organic framework (Eu3+@UiO-(COOH)2) was developed for the sensitive detection and visual analysis of CIP in environmental and food samples. First, ligand screening was achieved through theoretical calculations (ligand excited-state energy levels, frontier molecular orbitals, and electrostatic potential distribution) to probe the ligand modulation of fluorescence properties. Subsequently, based on the ligand engineering strategy for synthesizing Eu3+@UiO-(COOH)2 with excellent fluorescence performance and CIP self-fluorescence, a smartphone-integrated ratiometric fluorescence sensing platform was constructed to achieve rapid quantification of CIP via the blue/red light intensity ratio (B/R), with a limit of detection (LOD) as low as 36 nM, along with a mobile phone-based rapid visualization and quantification function. The systematic study demonstrated that the quenching effect of CIP on Eu3+@UiO-(COOH)2 fluorescence originated from a synergistic multipath mechanism: photoinduced electron transfer (PET) between the ligand and CIP was dominant, supplemented by dynamic quenching and inner filter effects (IFE). In addition, the sensing platform demonstrated reliability in complex matrices. This study provides a novel solution for antibiotic contamination monitoring with both laboratory accuracy and field applicability.

Antibiotic residues in medical sewage pose public health risks, necessitating integrated detection‐degradation solutions. Here, a novel Cu‐Fe 3 O 4 /Polymer Dots hybrid (CP), featuring specific recognition of chlortetracycline (CTC), restoration of peroxidase (POD)‐like activity, and outstanding fluorescence characteristics, is successfully constructed using Cu‐Fe 3 O 4 nanoparticles (CFO) as the core, with polymer dots (PDs) functionalizing the outer layer. Leveraging the unique properties of CP, a multifunctional platform is developed for the simultaneous fluorescence/colorimetric detection of CTC, as well as photothermal and recognition‐enhanced POD activity for antibiotic degradation and bacterial disinfection. The limit of detection (LOD) for CTC by CP are determined to be 1.86 n M for fluorescence and 64.2 nM for colorimetric detection, respectively. Comprehensive characterization reveals that the fluorescence quenching of CP by CTC occurred via dynamic quenching mechanisms, primarily through intermolecular collisions. The collision between CTC and CP leads to the release of PDs, thereby exposing the active catalytic sites and reactivating POD‐like activity, which not only achieves accurate detection of CTC, but also facilitates recognition‐enhanced degradation of CTC and disinfection of water bacteria. This work introduces a novel approach to the design of recognition‐functionalized nanozymes and offers a promising strategy for the environmental monitoring and remediation of antibiotic pollutants.

The accurate, sensitive, and efficient detection of enrofloxacin (ENR) residues is critically important for protecting public health and ensuring environmental safety. Herein, a novel electrochemical sensing platform based on a TAPB-PDA covalent organic framework integrated with reduced graphene oxide (TAPB-PDA-COFs/RGO) for the sensitive and selective detection of ENR in aqueous environments was developed. The TAPB-PDA-COFs/RGO leverages the high surface area and ordered pore structure of COFs alongside the excellent electrical conductivity of RGO, resulting in enhanced electrochemical performance. Under optimized conditions, the sensor exhibited a wide linear detection range (0.01-150 µmol L-1), a low detection limit (0.028 µmol L-1), and high selectivity even in the presence of structurally similar fluoroquinolones. The sensor also demonstrated good stability and reproducibility. When applied to spiked tap water samples, the platform achieved satisfactory recoveries of 84.1-99.7% and outperformed the conventional HPLC method at low ENR concentrations. These results highlighted the potential of the TAPB-PDA-COFs/RGO composite as a promising tool for environmental monitoring of antibiotic residues.

The production and buildup of sulfamethazine (SMZ) and resistance genes for sulfonamide antibiotics (sul1) pose a serious risk to environmental and public health safety. Creating advanced sensing systems that are both highly sensitive and selective for the prolonged observation of SMZ concentrations in the environment, along with the quantification of sul1 gene prevalence, aims to identify trends in resistance, posing a considerable challenge. Here, we devised a platform (SMZ-sul1 multi-mode detection platform) that allows for the fluorescence detection of SMZ in environmental samples. This is achieved through the competition for the aptamer between the complementary base and SMZ, along with the colorimetric, photothermal, and electrochemical tracking of sul1, using a magnetic separation unit (FP@cDNA). MOF-818@PtPd (MPP) nanozymes with high peroxide mimetic enzyme activity were linked to FP@cDNA through Zr-O-P bond and employed as a catalyst for the 3,3’,5,5’-tetramethylbenzidine (TMB) oxidation, as well as for electrocatalytic hydrogen peroxide (H2O2) reduction. The ability of Cas12a to perform trans cleavage was activated by its precise identification of the sul1, leading to the non-selective cutting of single-stranded DNA (ssDNA). Thereafter, the MPP nanoparticles were released into the supernatant, where they catalyzed the oxidation of TMB. Alternatively, the functioning CRISPR/Cas12a system specifically targeted and cleaved ssDNA present on the electrode, resulting in altered loading of MPP nanozymes and a decrease in the current associated with the catalytic reduction of H2O2. The remarkable magnetic separation capabilities of FP@cDNA, combined with the superior target recognition features of CRISPR/Cas12a and aptamer, facilitated the creation of a highly sensitive detection system, achieving detection limits of 0.67 pM for SMZ and 7.6 fM for sul1, and exhibit great potential for monitoring and prediction in the field of public health.

The reaction of bipyridine 3,7-di(3-pyridyl)-1,5-dioxa-3,7-diazacyclooctane (L) with copper thiocyanate produces a discrete metallamacrocycle [Cu(L)(SCN)2(DMF)]2 (1). In complex 1, two cis-coordinated ligands combine with two copper ions to form an unabridged 24-membered macrocycle. Each copper ion is five-coordinated with two nitrogens from separate ligands, two nitrogens from thiocyanates and one oxygen from the dimethylformamide (DMF) solvent. Complex 1 has been characterized using single-crystal X-ray diffraction, optical and thermal analyses and antimicrobial activity measurements. The solid electron paramagnetic resonance (EPR) analysis of complex 1 yielded a characteristic structural g factor value of 2.147. In addition, the thermal analysis established that the complex is thermally stable at up to 176 °C. The antimicrobial activity measurements demonstrated that both the ligand and complex 1 exhibit an inhibitory effect on two strains, where the complex exhibits a significantly greater inhibition relative to that of the free ligand (p < 0.05).

The simple, rapid, and simultaneous detection of multiple foodborne pathogens in food is crucial for ensuring public safety. In this study, a rational design strategy for lanthanide-based metal-organic frameworks (Ln-MOFs), informed by theoretical calculations, was proposed. The calculated results were experimentally verified to screen out the optimal Ln-MOF for fluorescence efficiency. The selected Ln-MOFs were coupled with phages that exhibit specific pathogen recognition to develop phage@Ln-MOF fluorescent probes, while the magnetic nanoparticles were conjugated with phages to form capture probes. On this basis, a fluorescent biosensor was developed for the simultaneous detection of three major foodborne pathogens-Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Salmonella. This sensor facilitated the detection of all three pathogens within 15 min, with limit of detection (LOD) as low as 1 CFU/mL. Moreover, this fluorescent biosensor was compatible with on-site visual detection, utilizing a self-designed portable dark box and smartphone-assisted visualization, achieving an LOD of approximately 1-2 CFU/mL for E. coli, S. aureus, and Salmonella. This work demonstrates a novel approach for the rapid on-site detection of multiple foodborne pathogens, which holds promise for advancing field-ready diagnostic tools in food safety monitoring.

The growing demand for real-time, non-invasive, and cost-effective health monitoring has driven significant advancements in portable point-of-care testing (POCT) devices. Among these, optical biosensors have emerged as promising tools for the detection of critical biomarkers such as uric acid (UA) and blood glucose. Different optical transduction methods, like fluorescence, surface plasmon resonance (SPR), and colorimetric approaches, are talked about, with a focus on how sensitive, specific, and portable they are. Despite considerable advancements, several challenges persist, including sensor stability, miniaturization, interference effects, and the need for calibration-free operation. This review also explores issues related to cost-effectiveness, data integration, and wireless connectivity for remote monitoring. The review further examines regulatory considerations and commercialization aspects of optical biosensors, addressing the gap between research developments and clinical implementation. Future perspectives emphasize the integration of artificial intelligence (AI) and healthcare for improved diagnostics, alongside the development of wearable and implantable biosensors for continuous monitoring. Innovative optical biosensors have the potential to change the way people manage their health by quickly and accurately measuring uric acid and glucose levels. This is especially true as the need for decentralized healthcare solutions grows. By critically evaluating existing work and exploring the limitations and opportunities in the field, this review will help guide the development of more efficient, accessible, and reliable POCT devices that can improve patient outcomes and quality of life.

Microcystin-leucine-arginine (MC-LR), stands out as the most lethal and broadly occurring variant of microcystins, which are harmful substances generated by cyanobacteria during periods of excessive nutrient enrichment in water bodies. Even at low levels, MC-LR can cause acute or chronic hepatic injury, leading to inflammation and potentially promoting tumorigenesis, thereby imposing a significant burden on human health. Vigilant surveillance of MC-LR is vital for safeguarding both the well-being of the public and environmental security. Optical sensors are particularly advantageous for the detection of MC-LR, owing to their exceptional sensitivity and ease of use. This review presents a comprehensive overview of the current advancements and emerging trends in optical sensors for MC-LR detection, focusing on two primary aspects: recognition elements and optical signal transduction. Recognition elements, including enzymes, antibodies, molecular imprinted polymers (MIPs), and aptamers, are summarized along with their characteristics. The review also thoroughly discusses optical signal transduction and its performance, specifically addressing colorimetry, fluorescence, surface-enhanced Raman scattering (SERS), surface plasmon resonance (SPR), electrochemiluminescence (ECL) and other signal transduction methods. Additionally, the review provides a summary of the achievements and challenges of current optical sensors, as well as future application prospects for MC-LR optical sensors. This systematic review aims to facilitate the further development of optical sensors for detecting microcystins.

Diabetic wounds experience a hyperglycemic, hypoxic environment, combined with ongoing oxidative stress and inflammatory imbalances, significantly disrupts normal healing process. Advanced hydrogels have been considered one of the most exciting medical biomaterials for the potential in wounds healing. Herein, a novel conductive hydrogel (HEPP), designed to release nanozyme (PTPPG) in response to its microenvironment, was created to facilitate glucose (Glu) catabolism. Furthermore, the HEPP integrates photodynamic therapy (PDT), photothermal therapy (PTT), and self-cascading reactive oxygen species (ROS) to prevent bacterial infections while ensuring a continuous supply of oxygen (O2) to the wound. The HEPP not only adeptly controls high ROS levels, but also enhances the regulation of inflammation in the wound area via electrical stimulation (ES), thereby promoting healing that is supported by the immune response. Studies conducted in vitro, along with transcriptomic analyses, indicate that ES primarily mitigates inflammation by regulating Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The effects of HEPP combined with ES are primarily connected to their impact on TNF signaling pathways. By reducing the formation of ROS and employing ES to effectively lessen inflammation, this approach offers an innovative method to manage complicated diabetic wounds, ulcers, and a range of inflammatory conditions linked to infections.

Bacterial infections represent a significant and ongoing challenge to public health worldwide. Metal-organic frameworks (MOFs), owing to their distinctive structural features and tunable physicochemical properties, have demonstrated considerable potential in antibacterial applications. Extensive research has been conducted to explore the application of MOFs in antimicrobial contexts. This review systematically examines the underlying antibacterial mechanisms of MOFs, including the release of metal ions, the generation of reactive oxygen species (ROS), and physical disruption of microbial membranes. Furthermore, it also discussed the specific applications of MOFs against various bacterial species and evaluates their prospective roles in the development of advanced antibacterial strategies.