Postoperative delirium (POD) is a severe postoperative neurocognitive complication associated with neuroinflammation and blood-brain barrier dysfunction. As a clinically relevant circulating biomarker for POD, S100-β detection is of great importance for accurate diagnosis and progression evaluation. Traditional approaches generally rely on converting antigen-antibody recognition events into the changes in labeled signal molecules, while neglecting the intrinsic charge properties of S100-β. Herein, a bioinspired microchannel-based ion current rectification (ICR) sensor was developed for sensitive S100-β detection, where S100-β antibodies were immobilized on the microchannel surface to simulate natural molecular recognition processes. The low isoelectric point of S100-β (∼4.7) renders the protein negatively charged under neutral conditions. Specific antigen and antibody recognition increased the interfacial negative charge density of the microchannel, thereby facilitating cation transport and enhancing the rectification response under an applied electric field. This process mimics the biological processes of channel opening and ion influx in living systems. The detected rectification ratio (RR) values was linearly correlated with the logarithm of S100-β concentration in the range of 0.01 ∼ 5.0 ng/mL with a detection limit of 4.0 pg mL-1 (S/N = 3). The sensor also showed good selectivity, as well as high stability with small RSD of 2.45%. The proposed sensor was successfully applied to the clinical serum analysis, showing good agreement with enzyme-linked immunosorbent assay and high recovery rates of 97.8% - 104.0%. This work provides a promising strategy for POD-related biomarker analysis and broadens the application of bioinspired microchannel-based ICR sensors in clinical diagnostics and bioanalytical sensing.

Leukemia, a critical hematological malignancy, demands early and accurate diagnosis to improve outcomes. In present work a 3D-printed microfluidic platform enables sensitive, label-free PHB2 detection via an AgNP-based paper immunosensor. Silver nanoparticles enhance electron transfer kinetics and provide a high surface area for efficient antibody immobilization, improving sensor performance. Electrochemical impedance spectroscopy (EIS) measurements show a stepwise increase in charge-transfer resistance (Rct) upon antigen-antibody interaction, confirming the sensing mechanism. The immunosensor exhibits a linear detection range of 2.5-40 ng mL-1 with a limit of detection of 2.5 ng mL-1. The platform demonstrates high selectivity against interfering biomarkers, excellent reproducibility, satisfactory recovery in spiked samples, and stable performance for up to 15 days. Biological validation using serum samples (animal serum and synthetic serum), HL-60 cell lines, and a BALB/c mouse model confirms its applicability in complex matrices. In silico and in vitro studies further support PHB2 as a diagnostic target. The platform offers a sensitive, portable, and cost-effective approach for point-of-care leukemia screening.

Serum thyrotropin (thyroid-stimulating hormone, TSH) is the most sensitive and specific biomarker for evaluating thyroid function, yet conventional immunoassay often suffer from limited sensitivity, complex instrumentation, and insufficient portability for point-of-care applications. Herein, we developed a portable photoelectrochemical (PEC) immunoassay based on a ZnO/Ag/g-C3N4 ternary Z-scheme heterojunction for the highly sensitive and selective detection of TSH. The hierarchical ZnO nanoflower scaffold was successively decorated with Ag nanoparticles and g-C3N4 nanosheets, forming intimate interfacial contacts that significantly promote charge separation and visible-light harvesting. Alkaline phosphatase (ALP)-labeled immunocomplexes catalytically convert L-ascorbic acid 2-phosphate (AAP) to ascorbic acid (AA), which served as an effective hole scavenger to amplify the photocurrent. Notably, the developed immunoassay exhibited a broad linear range spanning five orders of magnitude (R[2] = 0.9939) with a detection limit (LOD) of 0.71 pg mL[-1], with reliable interference immunity and accuracy. The integration of portable smartphone-based readout, ultrasound-enhanced piezo-phototronic effects, and the robust Z-scheme charge-transfer mechanism provides a versatile and reliable platform for point-of-care thyroid-function screening.

Uranium, a radioactive and toxic pollutant, poses significant threats to human health. The development of sensitive platforms for uranium detection and bioimaging remains challenge. Herein, a pyridine-based covalent organic framework (COF) was synthesized via a Schiff-base reaction using 2,2'-bipyridine-5,5'-dicarbaldehyde (Bpydah) and 1,3,5-tris(4-aminophenyl)benzene (TAPB). Subsequently, europium ions (Eu[3+]) were anchored to the pyridinic nitrogen sites of the COF framework via post-synthetic coordination, enhancing the intrinsic fluorescence and yielding a europium-functionalized sensor (COF@Eu). Attributed to the combined contributions of photoinduced electron transfer (PET) and Förster resonance energy transfer (FRET), COF@Eu exhibits a fluorescence "turn-on" response toward uranyl ion (UO2[2+]), with a detection limit of 3.3 nM and good reliability in complex sample matrices (RSD < 2.9%). Moreover, the "turn-on" fluorescence response, coupled with favorable biocompatibility and low cytotoxicity of COF@Eu, facilitates UO2[2+] imaging in cells and mice. This in vivo imaging capability highlights the potential of COF@Eu for visualizing internal uranium exposure. This work establishes a multifunctional platform, offering a potential strategy for environmental monitoring and nuclear toxicology.

Timely and accurate diagnosis of Lyme disease (LD) remains limited by complicated serological testing, which requires specialized laboratory equipment and has a multi-day turnaround, thereby limiting its utility in point-of-care (POC) settings. We have previously demonstrated a grating-coupled fluorescent plasmonic (GC-FP) biosensor in a microfluidics-based format (MF) for serological detection of LD. In this work, we demonstrate translation of an MF to a simplified dipstick (DS) assay. The assay utilizes miniaturized 4 × 4 mm gold-coated chips with a nanoscale grating that enhances fluorescence through surface plasmon-coupled emission (SPCE). The unique dipstick-based workflow eliminates the need for microfluidic pumps and complex instrumentation, with a total assay time of 24 min. The DS format integrates both tiers of the standard two-tiered diagnostic algorithm on a single chip, enabling simultaneous detection of first-tier screening antigen C6 and second-tier confirmatory antigens VlsE, DbpA, and DbpB. Validation was performed using thirty human serum samples tested in DS GC-FP chips, MF GC-FP chips, and a commercially available FDA-approved LD diagnostic assay (ZEUS Borrelia MTTT®). Using a strict two-tiered scoring approach, the DS format achieves 93.33% accuracy, 86.67% sensitivity, & 100% specificity with the limited sample set that was tested. With a single-tiered scoring approach, the DS format yielded equivalent diagnostic results to the MTTT and MF formats. The DS format substantially reduces equipment requirements, material costs, and operational complexity while preserving diagnostic accuracy, making it well-suited for deployment in urgent care centers, physician offices, and resource-limited settings.

Thermal nociceptive sensors capable of distinguishing innocuous and noxious thermal stimuli are crucial for self-protective humanoid robotics, adaptive prosthetics and intelligent human-machine interactions. However, most artificial thermal nociceptors lack the threshold-like, nonlinear and ion-mediated required to emulate biological thermal nociception mediated by transient receptor potential vanilloid 1(TRPV1), a key heat-activated ion channel protein in humans. Here, we report a neuromorphic thermal nociceptive sensing system consisting of an ion-regulated thermal sensor (iRTS) and an ion-gated synaptic transistor (iGST) based on layered semiconductors. Through ionic modulation of nonlinear thermally activated charge transport in the layered WSe2/MoS2 heterojunction, the iRTS exhibits a clear turning point at ∼320 K, close to the human noxious-heat perception threshold, beyond which the thermally evoked current increases nonlinearly with a high sensitivity of up to ∼35% K[-1], while maintaining an ultrahigh resolution of 0.005 K and an mA-level thermally evoked output current. By integrating the iRTS with the iGST, these thermal nociceptive signals are further converted into post-synaptic outputs that exhibit adaptive threshold modulation and sensitization behaviors, including hyperalgesia and allodynia-key features of biological thermal nociception. In addition, the iGST output is quantitatively mapped to a projected robotic finger-angle response, extending the artificial nociceptive pathway from thermal sensing and synaptic processing to behavior-level output. These results establish a high-performance neuromorphic thermal nociceptive sensor platform and offer a device-level strategy for intelligent robotics and adaptive human-machine interfaces.

Tumor-derived exosomes (TEXs) hold immense promise as biomarkers for cancer diagnosis, but sensitive and accurate identification is hindered by their intrinsic heterogeneity and extreme scarcity. Co-profiling of exosomal protein and microRNA (miRNA) at the single-molecule level may greatly enhance the precision of cancer diagnosis and prognosis. Herein, we present a single microbead-confined dual-mode detection system that selectively captures TEXs for concurrent quantification of protein and miRNA biomarkers. Exosomal proteins are quantified by measuring fluorescence signal concentrated on a single microbead-based enrichment platform. After on-bead lysis, individual miRNA is recognized by the two peptide nucleic acids (PNAs) to form a strict one-to-one correspondence with the intense light-scattering signal of gold nanoparticles (AuNPs), enabling single-molecule counting analysis. Through comprehensive profiling, a panel of four conjoint biomarkers achieve the highest diagnostic accuracy of 98.33%, outperforming any individual markers or alternative combinations. Importantly, this is the first demonstration of a universal PNA modification strategy that harnesses a DNA mediator to prevent AuNPs self-aggregation. This platform can also be adapted to other cancers by simply changing the aptamers and PNAs to target corresponding biomarkers, showing significant potential for advancing exosome-based liquid biopsies and accelerating the development of next-generation clinical diagnostic tools.

Flexible piezoresistive sensors are extensively applied in human physiological monitoring and dexterous hand motion detection. However, they often suffer from a trade-off between high sensitivity and wide sensing range, as well as limited linearity induced by the intrinsic microstructural drawbacks. In this study, we propose a flexible piezoresistive sensor featuring a well-ordered and three-level pyramidal microstructure (OTPm) fabricated by laser direct writing and wet etching to overcome such limitations. Benefiting from stress concentration at pyramid tips and stepwise interfacial contact, the OTPm sensor achieves progressive conduction behavior, which effectively enhances sensitivity and suppresses pressure saturation. Notably, the OTPm sensor exhibits three linear sensitivity stages of 77.80, 39.84, and 19.20 kPa[-1], a broad detection range up to 800 kPa, a low limit of detection of 98 Pa, and a response time of 91.2 ms, coupled with stable sensing performance over 10,000 cycling tests. These sensing features enable the sensor to effectively detect various physiological signals and dynamic human motion changes. Furthermore, the developed 3×3 sensor array realizes three-dimensional(3D) pressure distribution imaging and validates reliable mechanical sensing capability during grasping motions. With the balanced sensing performance, the proposed sensor presents great application potential for medical rehabilitation, robotic control, and human-machine interaction.

The development of rapid, sensitive, and specific nucleic acid assays is pivotal for advancing molecular detection in clinical diagnosis, food safety, and environmental monitoring. Clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) systems, renowned for their programmable and signal amplification capacity, have emerged as efficient tools for meeting these challenges. However, the intrinsic sensitivity of CRISPR/Cas assays relying on a single Cas effector is typically confined to the picomolar level, often necessitating complex nucleic acid preamplification. Cascaded CRISPR systems, which integrate sequential enzymatic reactions or multiple CRISPR effectors, can address this limitation by achieving nucleic acid preamplification-free signal enhancement. This review starts with the introduction of the design principles and working mechanisms of cascaded CRISPR strategies, encompassing Enzyme-Coupled cascades, Multi-effector class 2 CRISPR cascades, and Type III CRISPR-mediated cascades. Then, we highlight the deployment of these techniques across diverse bio-sensing scenarios, ranging from disease diagnosis to food and environmental surveillance. Finally, critical challenges and emerging frontiers are discussed, including integration with digital detection platforms and AI-assistant algorithms.

Precise regulation of nanozyme activity is crucial for expanding their practical applications in complex multi-domain environments, yet designing a bidirectional precision regulation strategy remains a significant challenge. Herein, this study developed a novel strategy based on photoinduced and phosphate-mediated of nanozymes, enabling bidirectional and dynamic regulation of enzymatic activity. Specifically, UV-responsive nitrogen-doped carbon quantum dots (NCDs) served as photosensitive materials were introduced with 2D nanosheets copper-iron layered double hydroxide (CuFe-LDH) to form a composite structure (NCDs/LDH, NL). Photo-induced method could enhance peroxidase-like (POD) activity by facilitating interfacial electron transfer, which accelerates the valence state cycling of copper and iron centers. In addition, phosphate-mediated coordination suppressed the catalytic reaction by forming metal-oxygen-phosphorus coordination bonds that alter the electron density of the active sites. Both regulatory modalities operate by modulating the electron transfer and valence transition processes at the copper and iron active centers. Based on this mechanism, the constructed nanozyme-based sensor platform demonstrates effective performance in the accurate screening of multiple antioxidants. Principal component analysis of the response dataset revealed well-defined clustering of all six antioxidants, with 95% confidence ellipses being sharply separated, demonstrating its high discrimination capability. This work not only elucidates the regulatory principles of photo-induced method and phosphate-mediated coordination in the bidirectional control of nanozyme activity, but also provides a new design pathway for developing intelligent nanozymes applicable to complex biological and environmental systems.

A constitutional dynamic DNA network (CDN) integrated with catalytic hairpin assembly (CHA) was developed for the accurate ratiometric electrochemical detection of multiple microRNAs (miRNAs). To overcome the limitations of conventional single-signal multiplex assays, this strategy relies on a [2×2] equilibrium system that undergoes target-triggered dynamic reconfiguration in the presence of miRNA-21 or miRNA-221. This reconfiguration regulates the cleavage of specific signal probes at the electrode interface, while distinct dynamic states initiate orthogonal CHA pathways. Subsequently, generated target mimics adaptively amplify the DNA assembly, producing opposing methylene blue (MB) and ferrocene (Fc) electrochemical responses for dual-channel ratiometric readout. Under optimal conditions, a broad linear range from 1 fM to 1 nM was achieved, with detection limits of 0.57 fM and 0.68 fM for miRNA-21 and miRNA-221, respectively. The analytical reliability of the method was further demonstrated through the successful discrimination of endogenous miRNA expression levels in HeLa, MCF-7, and MHCC97L cell lysates. Ultimately, this adaptive dynamic DNA system provides a highly precise and robust platform for multiplexed biomarker analysis in complex biological samples.

We report MetaVision-SPR, a 96-well chromatic metasurface plasmon resonance (Meta-SPR) imaging platform for serum biomarker quantification and apparent kinetic analysis. The system integrates a nanocup-array Meta-SPR chip, light-emitting diode (LED) illumination, an industrial camera, and computational correction including automated well recognition, sucrose-reference-based optical flat-field correction, and Δ(R-G) chromatic readout. Spectral simulation and optical response matching identified the 20/75/25 nm Ti/Ag/Au structure and Δ(R-G) signal as the optimal chip-readout combination for quantitative imaging. Flat-field correction reduced inter-well variation in a Protein A/immunoglobulin G (IgG) assay from 26.74% to 6.74%, while programmable shaking improved mass transport in the open-well format. Using gold nanoparticle (AuNP)-enhanced sandwich assays, the platform enabled sensitive detection of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) with limits of detection (LoDs) of 5.0 pg/mL for AFP, 10.0 pg/mL for CEA and 0.49 U/mL for CA19-9. Clinical serum measurements showed reference-method consistency with hospital electrochemiluminescence immunoassay (ECLIA) and commercial enzyme-linked immunosorbent assay (ELISA) results. In addition, the system supported real-time measurement of binding curves for antibody-drug conjugate and lipopolysaccharide-related interactions, yielding apparent kinetic parameters suitable for high-throughput screening. These results support MetaVision-SPR as a low-hardware-cost 96-well chromatic Meta-SPR workflow for serum biomarker measurement and apparent interaction ranking.

Diabetes, hyperuricaemia, dyslipidaemia, and related metabolic disorders often coexist, creating a need for point-of-care testing (POCT) that can analyse multiple biomarkers from a small whole-blood specimen. Most disposable electrochemical strips remain single-analyte devices and therefore require repeated sampling and separate strips. Here, we developed a disposable five-channel electrochemical test card based on a fivefold rotationally symmetric stepped radial microfluidic architecture. A 10 μL aliquot of whole blood is introduced once through the central inlet and passively distributed to four amperometric channels for glucose (Glu), uric acid (UA), total cholesterol (TC), and β-hydroxybutyrate (β-HB), together with an impedance channel for independent haematocrit (HCT) estimation. The injection-moulded substrate integrates embedded copper traces with gold-plated sensing areas and requires no pump or valve. A glucose-preloading challenge produced a mean maximum receiver-channel crosstalk of 0.675 ± 0.077%, with a highest individual value of 0.815% under the nominal loading condition. In 20 clinical whole-blood samples, test-card results correlated with the corresponding reference methods (R[2] = 0.9484-0.9959), and analyte-specific Bland-Altman analysis supported preliminary agreement within the tested ranges. This disposable microfluidic electrochemical test card enables comprehensive multi-metabolite analysis under POCT conditions using only 10 μL whole blood, and offers a promising technical solution for next-generation precision management of metabolic diseases and multiplex POCT systems.

CRISPR/Cas12a combined with nucleic acid amplification enables highly specific and sensitive detection. However, its broader deployment is constrained by protospacer adjacent motif (PAM) dependence, multistep workflows, and limited reagent practicality. Here, we identify a PAM-independent Cas12a activator, termed mosaic DNA, which exhibits structural features intermediate between single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). Building on this finding, we develop a PAM-independent mosaic switch triggered by a solid-liquid phase transition, thereby addressing these limitations within a single platform. Distinct from previous reports, our experiments show that this activator is generated prior to the digestion of dsDNA into ssDNA by the lambda exonuclease, forming the basis of lambda exonuclease-driven Cas12a activation, a process we refer to as the mosaic switch. Mosaic switch can detect arbitrary dsDNA with sensitivity comparable to that of PAM-containing dsDNA, and maintain single-nucleotide discrimination. Lyophilizing mosaic switch reagents and encapsulating them in paraffin improve stability and usability, which also enables straightforward one-pot integration with recombinase polymerase amplification (RPA) via a solid-liquid phase transition. Applied directly to 58 extraction-free mpox clinical samples, this platform showed complete concordance (100%) with quantitative PCR. This CRISPR/Cas12a platform maintains analytical performance while broadening the range of targets, simplifying the workflow, and enhancing reagent practicality, showing great potential for clinical deployment.

Quantitative assessment of cellular oxidative stress requires parallel matched profiling of intracellular redox state and extracellular respiratory activity, yet paired sensing approaches remain limited. Here, we present a dual-fluorescent sensing platform combining a genetically encoded redox biosensor (roGFP2-Tsa2ΔCR) with an optical oxygen sensor embedded in microwell plates for parallel, non-invasive quantification of intracellular hydrogen peroxide, a major reactive oxygen species (ROS), and oxygen consumption rates (OCR) in industrial yeast systems. The roGFP2-based sensor was stably expressed in Saccharomyces cerevisiae (S. cerevisiae) and Yarrowia lipolytica (Y. lipolytica), enabling dynamic monitoring of oxidative stress at population, single-cell, and subcellular levels, while oxygen-sensitive films provided real-time respiration measurements. Using this platform, we identified distinct redox-respiration phenotypes between the two yeasts. Crabtree-positive S. cerevisiae exhibited low OCR and mitochondrial ROS during glucose cultivation, whereas growth on ethanol-glycerol increased OCR and mitochondrial ROS by ∼2.5-fold and 12%, respectively. In contrast, the obligate respiratory yeast Y. lipolytica displayed 3-fold higher OCR and 16% lower mitochondrial ROS than respiring S. cerevisiae, indicating differences in respiratory oxidative burden. Antimycin A treatment (1.25 μM) reduced OCR by 85% in respiring S. cerevisiae while increasing mitochondrial ROS by 27% when compared to corresponding basal levels, whereas Y. lipolytica showed greater resistance to respiratory and oxidative perturbations. By combining intracellular redox sensing with extracellular oxygen measurements, this platform enables paired quantitative profiling of redox state and respiration in living cells. The approach provides a scalable framework for evaluating cellular fitness, stress tolerance, and metabolic state, with broad applications in biomanufacturing and development of yeast-based disease models.