Biosensors and Bioelectronics最新文献

Tumor microenvironment (TME)-responsive theranostic nanosystems hold considerable promise for cancer therapy. However, converting transient therapeutic effects into sustained and amplified antitumor efficacy remains a challenge due to the absence of dynamic feedback mechanisms in conventional strategies. Herein, we construct an activatable self-reinforcing FeMOF-Au@HA nanoplatform to potentiate ferroptosis via starvation and photothermal sensitization for amplified cancer therapy. This nanoplatform is fabricated through a stepwise strategy by anchoring ultrasmall Au NPs onto FeMOF followed by hyaluronic acid (HA) functionalization. Upon encountering tumor cells, the HA shell binds to CD44 receptors, promoting tumor-targeted accumulation and cellular internalization of FeMOF-AH. After cellular uptake, FeMOF-AH initiates Au-catalyzed glucose oxidation, depleting glucose to induce starvation therapy (ST) and the generation of H₂O₂. Meanwhile, GSH reduces Fe³⁺ to Fe²⁺, facilitating the conversion of H₂O₂ to ·OH. The subsequent GSH exhaustion and ·OH accumulation disrupt redox equilibrium, inducing glutathione peroxidase 4 inactivation and lipid peroxidation buildup that drive ferroptosis. Ferroptosis further provokes mitochondrial dysfunction, depleting ATP and suppressing heat shock protein 70 (HSP70), thereby attenuating thermotolerance and sensitizing tumors to mild photothermal therapy (PTT, 45 °C). Under 808-nm laser irradiation, mild photothermal heating accelerates glucose oxidation and Fenton catalysis, reinforcing ST and ferroptosis. Notably, ST fuels ferroptosis via metabolite supply, and ferroptosis attenuates thermoresistance to potentiate mild PTT that amplifies oxidative damage, establishing a self-reinforcing therapeutic network. Consequently, FeMOF-AH exhibits enhanced tumor-targeted accumulation by in vivo fluorescence imaging and superior antitumor efficacy over monotherapies with a 92.6% tumor inhibition rate under laser irradiation without systemic toxicity. This nanoplatform offers a new avenue for designing feedback-amplified nanomedicines for durable and enhanced cancer therapy.

Addressing the global food shortage crisis requires precise and timely diagnostics of plant exogenous stresses (such as pesticides) to enhance the quality and yield of crops. Plant-wearable sensors (PWS) offer a promising approach to real-time monitoring of pesticides for plant health but remain limited by challenges in low signal-conversion efficiency and poor mechanical adaptability at the plant-sensor interface. Here we report a robust PWS by embedding an aggregation-induced emission (AIE) silver nanoclusters@zeolitic imidazolate framework@polydopamine (AgNCs@ZIF@PDA) composite into a plant-adaptive hydrogel patch, enabling the on-site monitoring of pesticide information. The conformal hydrogel interface of the PWS utilizes an in-situ radical triggered sol-gel phase transition to lock into the abrupt hairy surface irregularities, resolving the issue of mechanical adaptability. The resultant AgNCs@ZIF@PDA-based hydrogel patch exhibits high sensitivity toward 2,4-dichlorophenoxyacetic acid, with a limit of detection as low as 26.7 ng/mL. Mechanism investigations elucidate that the synergistic combination of the AIE effect of AgNCs and the specific responsive behavior of the heterogeneous interface of PDA enhances the energy-transfer (signal-conversion) efficiency. Notably, the PWS enables non-invasive, continuous quantification of pesticide degradation kinetics. This robust fluorescence PWS enables real-time tracking of pesticides for plant health, thereby advancing the goals of precision chemical application and resource-efficient agriculture.

Rapid and selective detection of dengue virus serotypes remains challenging because of the co-circulation of antigenically related arboviruses. We developed a fully 3D-printed electrochemical biosensor for dengue virus serotype 2 non-structural protein 1 (DENV-2 NS1). The integrated three-electrode platform incorporated a graphite/polylactic acid working electrode modified in a single drop-casting step with preassembled monoclonal antibody-gold nanoparticle conjugates (mAb-AuNP). DENV-2 NS1 binding was monitored by cyclic voltammetry using [Fe(CN)₆]^3-/4- as a redox probe; immunocomplex formation partially blocked interfacial electron transfer and decreased the cathodic peak current. The response stabilized after 15 min and was linear from 0.15 to 0.75 μg L^-1 (1.75-8.74 pM), with R² = 0.9922 and a limit of detection of 0.061 μg L^-1 (0.71 pM). Three independently prepared biosensors showed a relative standard deviation of 3.4%, indicating good fabrication reproducibility. The immunosensor produced a substantially greater response to DENV-2 NS1 than to DENV-1 NS1, Zika virus NS1, or chikungunya virus E2 protein. In 100-fold-diluted human serum spiked at 0.15 and 0.25 μg L^-1, standard-addition analysis yielded recoveries of 106.0 ± 1.3% and 97.7 ± 1.1%, respectively. These findings demonstrate that one-step mAb-AuNP functionalization of fully 3D-printed electrodes provides a rapid, reproducible, and serotype-selective approach to NS1 detection, warranting further validation with clinical samples.

Accurate, multiplexed microRNA detection is critical for early cancer diagnosis. We present a droplet-based digital CRISPR/Cas13a platform for simultaneous, amplification-free detection of multiple miRNAs. By integrating double emulsion (DE) microfluidics with programmable crRNAs, the system achieves orthogonal, interference-free readouts, enabling precise absolute quantification in complex biological samples. The assay demonstrates high sequence specificity, robust orthogonality, and consistent performance across target combinations and matrices. Fluorescence-positive droplet counts correlate linearly with input concentrations, allowing quantification of miRNA-21, miRNA-29a, and miRNA-92a with 10 copies/μL representing the lowest concentration experimentally evaluated in this study. The applicability of the platform is further evaluated in a small proof-of-concept cohort of plasma samples from healthy controls and colorectal cancer (CRC) patients. This platform provides an amplification-free approach for multiplexed miRNA quantification and supports further development for clinical biomarker analysis.

Chlamydia trachomatis is a prevalent, often asymptomatic sexually transmitted infection, while molecular tests remain constrained by cost and infrastructure. Here, we report a label-free electrochemical lateral flow immunoassay (eLFIA) designed to address these challenges through an intuitive signal-on readout implemented in an indirect competitive format. A secondary antibody-mediated interfacial mass-loading strategy was introduced to amplify steric blocking and improve signal discrimination without requiring reporter labels. Mechanistically, sequential binding of primary and secondary antibodies forms a bulky protein assembly at the electrode-membrane interface, increasing charge-transfer resistance and reducing the effective electroactive area, thereby amplifying signal discrimination between positive and negative samples. Assay configurations were evaluated and fitted using a four-parameter logistic model. Incorporation of a secondary antibody delivered approximately a five-fold sensitivity enhancement relative to the single-antibody format. The optimized platform achieved a limit of detection of 10 ng/mL with a practical quantitative working range of ∼10-500 ng/mL (CV < 15%). Accuracy in simulated urine, artificial saliva, and simulated vaginal fluid yielded recoveries of ∼80-120% with matrix-independent calibration behavior. A portable NFC-enabled reader demonstrated the signal-on response, supporting potential translation to home-based testing. This secondary antibody-mediated signal-on, label-free eLFIA provides a scalable and user-oriented platform for C. trachomatis screening and surveillance, with potential utility in home-based testing to support infection control.