Biosensors-Basel最新文献

Filamentous fungi are increasingly recognized as versatile biological platforms for the development of advanced (bio)sensing technologies, owing to their extensive secretory capacity, material-forming ability, and intrinsic bioelectrical activity. This review critically surveys recent progress in fungal-based sensing within a multiscale framework spanning molecular, material, computational, and ecological domains, with particular emphasis on developments reported over the past five years. Key advances involving secretome-derived biomolecules, mycogenic nanomaterials, mycelium-based living materials, and fungal electrophysiology are discussed alongside emerging approaches for environmental monitoring that integrate sensor networks, imaging platforms, and data-driven analytics. Collectively, these works demonstrate that fungal systems can enhance biosensor sensitivity, selectivity, and sustainability, while enabling unconventional paradigms of signal transduction, material-integrated sensing, and biologically mediated computation. At larger spatial and temporal scales, mycelial growth dynamics and electrical activity provide measurable responses to mechanical, chemical, and environmental perturbations, supporting early applications in wearable devices, structural materials, and ecosystem monitoring. Despite significant progress, challenges remain in reproducibility, long-term stability, mechanistic understanding, and scalable device integration. Overall, the evidence reviewed highlights filamentous fungi as biologically adaptive and ecologically embedded systems with substantial potential to support next-generation (bio)sensing technologies, while underscoring the need for integrative approaches that combine biological insight with materials science, electronics, and artificial intelligence.

Fumonisin B1 (FB1) is a secondary metabolite produced by Fusarium species, exhibiting strong toxicity and classified as a Group 2B carcinogen by the International Agency for Research on Cancer. It poses a significant threat to both human and animal health. Therefore, developing a simple and reliable method for FB1 detection and analysis is imperative. In this study, a biosensor based on nucleic acid aptamers was developed, utilizing plasma-modified graphene oxide (mGO) as a fluorescence quencher for FB1 detection. This system leverages the interaction between mGO and FAM-APT (a nucleic acid aptamer labeled with 5-carboxyfluorescein, FAM), achieving fluorescence quenching through fluorescence resonance energy transfer (FRET) under excitation at 490 nm and emission at 520 nm. In the presence of FB1, FAM-APT specifically binds to FB1 and dissociates from the mGO surface, resulting in fluorescence recovery. Quantitative detection of FB1 was achieved by measuring the differential fluorescence intensity. The biosensor demonstrated excellent linearity over a concentration range of 10 to 5 × 10⁶ ng/L, with a detection limit (LOD) as low as 0.16 μg/L. Additionally, the sensor exhibited high specificity for FB1 among six common mycotoxins. In practical sample analysis, recovery rates ranged from 95.8% to 104.7% in corn samples and from 89.3% to 94.5% in rice samples. This aptamer-based biosensor features a simple structure, high sensitivity, and a wide detection range, providing important technical support for advancing mycotoxin research.

Lateral flow assays (LFAs) are among the most successful technologies for point-of-care and at-home testing, but further advances are needed to reduce costs and accelerate development. Alpaca-derived nanobodies (Nbs), single-domain antibody fragments, are promising immunoassay reagents across diverse applications. Their small size and ease of recombinant production make them particularly well suited for diagnostics. Here, we present a paper-based LFA targeting the SARS-CoV-2 nucleocapsid (N) protein that exclusively uses Nbs for direct antigen detection. We also demonstrate in-house synthesis of Nb-coated gold nanoparticles, enabling instrument-free visual readout and detection of N protein down to 40 ng/mL. This design avoids components that require mammalian cell culture and can be produced entirely from in-house reagents, simplifying manufacturing and lowering component costs. Because the assay is read visually without an external reader, it is well suited for deployment in resource-limited settings. Together, these results highlight the speed and practicality of developing Nb-based LFAs and suggest a broadly applicable strategy for detecting other clinically important disease biomarkers.

Early detection of cancer biomarkers in blood is critical for improving patient outcomes; however, conventional immunoassays often rely on complex instrumentation and are not well suited for point-of-care testing or multiplexed analysis. Herein, we present a dual-mode colorimetric-surface-enhanced Raman scattering (SERS) lateral flow immunoassay (LFIA) platform for multiplexed detection of cancer biomarkers, employing elongated rod-shaped silver nanoshells (ERNSs) as SERS nanotags. The ERNS features a rough Ag shell with internally incorporated Raman labeling compounds (RLCs), enabling plasmonic extinction for visual readout and strong SERS signals for quantitative analysis while preserving the external metal surfaces for efficient antibody conjugation. Leveraging these advantages, a multiplex LFIA capable of simultaneously detecting prostate-specific antigen (PSA) and carbohydrate antigen 19-9 (CA19-9) on a single strip was successfully demonstrated. Visual inspection enabled rapid discrimination of samples at or near clinically relevant cut-off levels, while Raman analysis achieved limits of detection of 8.0 × 10^-3 ng/mL for PSA and 5.4 × 10^-2 U/mL for CA19-9, corresponding to approximately 500-fold and 685-fold lower concentrations than their respective clinical thresholds. This ERNS-based colorimetric-SERS LFIA integrates rapid screening and highly sensitive quantification within a single platform and offers a versatile nanoprobe design strategy for multiplex biomarker detection and liquid biopsy-based diagnostic applications, with potential relevance to point-of-care settings.

Hexavalent chromium (Cr(VI)) is a high-priority environmental pollutant due to its strong oxidizing properties, which cause DNA damage and other severe health effects. Conventional detection methods are often costly and lack real-time monitoring capabilities, creating a strong demand for cost-effective, real-time biosensors that meet industrial requirements. In this study, we developed a novel biosensor for continuous Cr(VI) monitoring using a single-chamber microbial fuel cell (MFC). The biological element is an engineered Escherichia coli strain (ChrA-ChrB-E. coli), constructed by introducing Cr(VI)-resistant (ChrA) and Cr(VI)-reducing (ChrB) genes. The presence of Cr(VI) affects bacterial metabolism and electron transfer within the MFC, generating a measurable signal proportional to the contaminant's concentration. The biosensor demonstrated robust performance and characteristics. The recombinant strain retained functional activity after 450 days of storage at -20 °C. The system exhibited high sensitivity and excellent linearity (R² ≥ 0.999) across a broad Cr(VI) concentration range of 0.015-200 mg/L. During continuous monitoring of chrome tanning and electroplating wastewater, measurements deviated by less than 2.33% from the standard diphenylcarbazide (DPC) method; electroplating deviation was further reduced to -0.69% with EDTA pretreatment. In fishery water, the deviation was higher (-7.12%) due to dissolved oxygen (DO) interference but was reduced to -0.75% after mechanical stirring to remove DO. The biofilm bacterial community remained highly stable over six months in both wastewater types, with the inoculated ChrA-ChrB-E. coli strain maintaining dominance (>99.6%). These results substantiate the feasibility of using this biosensor for continuous, online, real-time detection of Cr(VI) in actual wastewater environments.

The global expansion of genetically modified (GM) crop cultivation has increased the demand for analytical platforms that can provide rapid, reliable, and cost-effective detection of GM-derived ingredients to support traceability, regulatory compliance, and accurate labeling. Conventional molecular assays such as polymerase chain reaction (PCR) and isothermal amplification are highly sensitive and specific but depend on sophisticated instrumentation and trained personnel, limiting their applicability in field settings. Here, we present a label-free and amplification-free nanobiosensor based on citrate-capped gold nanoparticles (AuNPs) for the direct colorimetric detection of the Cry1Ac gene associated with the MON87701 soybean event, without the use of polymerase chain reaction (PCR) or any enzymatic nucleic acid amplification step. The assay relies on the localized surface plasmon resonance (LSPR) of AuNPs, which induces a red-to-purple color transition upon hybridization between complementary DNA strands. Critical reaction parameters, including NaCl concentration, AuNP size, and ionic strength, were optimized to enable selective and reproducible aggregation. Integration with a Support Vector Machine (SVM) algorithm enabled automated spectral classification and semi-quantitative discrimination of GM content levels. The optimized AuNP-SVM system achieved high sensitivity (limit of detection ≈ 2.5 ng μL^-1, depending on nanoparticle batch), strong specificity toward Cry1Ac-positive sequences, and reproducible classification accuracies exceeding 90%. By eliminating enzymatic amplification steps, the proposed platform significantly reduces assay time, operational complexity, and instrumentation requirements, making it suitable for rapid on-site GMO screening.

Background: Brain temperature is an important determinant of neurological outcomes in ill infants, yet contributions of environmental temperature and cerebral blood flow remain uncovered because of the lack of non-invasive probes.

Methods: Using non-invasive cot-side probes, we examined how cerebral blood flow influences brain temperature during mild cold stress induced by incubator-to-cot transfer. We studied 43 clinically stable infants in a tertiary neonatal intensive care unit. After cot transfer, infants were routinely fitted with knit caps and wrapped in cotton blankets. Scalp and superficial and deep brain temperatures were measured using infrared and zero-heat-flux thermometers, and superior vena cava (SVC) flow-a proxy for cerebral blood flow-was assessed using Doppler velocimetry before, immediately after, and 2 h after transfer, adjusting for rectal temperature.

Results: Ambient temperature decreased from 29.7 (SD 0.8) °C to 26.8 (SD 0.9) °C, while rectal temperature remained stable. Scalp and brain temperatures declined after transfer but superficial and deep brain temperatures returned to baseline after 2 h of cap use. The regression coefficient between SVC flow and superficial brain temperature shifted from -0.176 (95% CI, -0.386 to 0.035) to 0.239 (-0.280 to 0.759) after transfer (difference: 0.415 [0.106 to 0.724]; p = 0.009), and then returned to baseline after 2 h (-0.079 [-0.528 to 0.372]).

Conclusions: Relationships between brain temperature and perfusion were successfully monitored using non-invasive cot-side biosensors; cerebral blood flow appears to shift from facilitating heat dissipation in warm conditions to supporting heat delivery during cold stress. These findings underscore the physiological role of cerebral blood flow in maintaining brain temperature.

Microfluidics-based preparation methods for cell-laden hydrogel microspheres are well-suited for large-scale comparative analysis of single or few cells. However, in existing studies, the preparation of cell-laden hydrogel microspheres and the cell culture process are typically separated, requiring the fabricated microspheres to be eluted and transferred from the preparation device to cell culture dishes or plates for cultivation. This transfer process can easily compromise sterility, while conventional cell culture methods consume more reagents and cause microsphere stacking, hindering single-cell observation and analysis. To address these issues, this paper presents an integrated microfluidic chip that sequentially enables droplet generation with cell encapsulation, gel droplet solidification, hydrogel microsphere trapping, and microsphere-based cell culture and analysis, facilitating the cultivation and observation of single or small numbers of cells. Integrating cell-laden microsphere preparation and 3D cell culture within a sealed chip structure reduces contamination risks associated with cell transfer, enables automation of multiple cell analysis workflows, and minimizes reagent and sample consumption. Using polydimethylsiloxane (PDMS) with good gas permeability and processability as the chip material, biocompatible fluorinated oil was selected as the oil phase for microsphere preparation. A mild sodium alginate-calcium ion gelation system was employed, where calcium ions were released under acidic conditions after droplet generation to trigger solidification, yielding uniform hydrogel microspheres. Under optimized conditions, the single-cell encapsulation efficiency for test samples of human myeloid leukemia cells (K562) was 33.8% ± 1.8%, with a size uniformity coefficient of variation (CV) reaching 3.85%. Cells encapsulated within hydrogel microspheres were cultured in 286 on-chip independent cell culture chambers, achieving >95% viability after 24 h.

The sensitive detection of microRNA-21 (miR-21), a key biomarker for various cancers, is crucial for early diagnosis, yet conventional methods often face limitations in sensitivity and operational complexity. Here, we report a label-free biosensor based on a suspended graphene field-effect transistor (GFET) for the direct electrical detection of miR-21. The suspended architecture isolates the graphene channel from substrate-induced interference, resulting in enhanced carrier mobility and reduced electrical noise. After surface functionalization with a specific probe, the GFET demonstrated a clear concentration-dependent response to target miR-21. The binding events were transduced into a monotonic increase in relative resistance (ΔR/R₀) and a positive shift of the Dirac point (V_Dirac), achieving a detection limit in the femtomolar (fM) range. These results establish the suspended GFET as a highly sensitive and robust platform for quantifying nucleic acid biomarkers, holding significant potential for biomedical research and point-of-care diagnostics.

We report a highly sensitive and interference-free electrochemical sensor for dopamine (DA) detection in the presence of uric acid (UA) and ascorbic acid (AA), based on an in situ deposited graphitic carbon nitride (g-C₃N₄) and polymethyl thymol blue (PMTB) nanohybrid modified screen-printed carbon electrode (SPCE). The as-fabricated g-C₃N₄/PMTB/SPCE was thoroughly characterized using various physicochemical techniques. The electrochemical behavior of the modified electrode was systematically investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The g-C₃N₄/PMTB/SPCE exhibited excellent electrocatalytic activity toward the selective oxidation of DA under optimized experimental conditions, including pH and scan rate. Interference-free detection of DA in the presence of AA and UA was achieved using DPV and chronoamperometric methods, revealing a wide linear concentration range, an ultralow limit of detection, and high sensitivity. Furthermore, the practical applicability of the proposed sensor was validated by determining DA in artificial biofluid samples, including blood serum, and urine. The recovery results obtained good agreement with those obtained using high-performance liquid chromatography (HPLC), confirming the reliability and accuracy of the developed sensing platform.