Search Results (96)

Flexible strain sensors capable of conformal integration with living organisms are essential for advanced wearable electronics, human–machine interaction, and plant health. However, many existing sensors require complex fabrication or rely on non-breathable elastomer substrates that interfere with the physiological microenvironment of skin or plant tissues. Here, we present a low-cost, breathable, and highly stretchable strain sensor constructed from biomedical materials, in which a double-layer medical elastic bandage serves as the porous substrate and an intermediate conductive medical elastic tape impregnated with carbon nanotubes (CNTs) ink acts as the sensing layer. Owing to the hierarchical textile porosity and the deformable CNTs percolation network, the sensor achieves a wide strain range of 100%, a gauge factor of up to 2.72, and excellent nonlinear second-order fitting (R² = 0.997). The bandage substrate provides superior air permeability, allowing long-term attachment without obstructing moisture and gas exchange, which is particularly important for maintaining skin comfort and preventing disturbances to plant epidermal physiology. Demonstrations in human joint-motion monitoring and real-time plant growth detection highlight the device’s versatility and biological compatibility. This work offers a simple, low-cost yet effective alternative to sophisticated strain sensors designed for human monitoring and plant growth monitoring, providing a scalable route toward multifunctional wearable sensing platforms. Full article

Sweat, which contains a rich array of biomarkers, serves as a vital biological fluid for non-invasive biosensing. Wearable sweat sensors have garnered significant interest owing to their portability and capacity for continuous monitoring. However, there are safety concerns regarding the direct contact of sweat sensors with the skin during the detection process. The chemical substances in the sensor patches may cause contamination of the epidermis when in contact with the skin, leading to skin allergic reactions. Sample collection and biosafety isolation are critical issues in wearable sweat detection. To address this, we develop a cactus-inspired biomimetic Janus membrane capable of unidirectionally transporting and concentrating sweat toward a designated detection zone. Through unidirectional transport from the hydrophobic layer to the hydrophilic layer of the Janus membrane, sweat droplets are enriched at the designated detection point of the conical hydrophilic pattern via Laplace pressure. The bionic osmosis-enrichment sensing patch effectively inhibits direct contact between indicators and skin, eliminating potential epidermal contamination. This achieved the effect of in situ perspiration collection under the premise of biosafety isolation. To rapidly and accurately analyze sweat biomarkers, we employ a deep learning (DL)-assisted fluorescence sensor for efficient and precise detection of biomarker concentrations. A dataset of 4500 fluorescence images are constructed and used to evaluate two DL and seven machine learning (ML) algorithms. The convolutional neural network (CNN) model could easily and accurately classify and quantitatively analyze the total concentration of the amino acid mixture, Ca²⁺ and Cl⁻, with 100% classification accuracy. The consistency between the detection results of actual sweat by the DL-assisted fluorescence method and fluorescence spectroscopy was 91.4–96.0%. This approach demonstrates high reliability in sweat collection and analysis, offering a practical tool for clinical health monitoring, early disease intervention, and diagnosis. Full article

Here, we report a facile technique for fabricating inkjet-printed PEDOT:PSS thermally active devices on commercial tattoo paper, subsequently transferred to Kapton substrate with pre-patterned copper tracks, to enable integration with other electronic systems. Printing parameters were investigated for consistent film quality. Electrical and thermal characterization confirmed stable ohmic behavior; after transfer, the device exhibited superior contact performance with lower measured electrical resistance. Temperature coefficient of resistance (TCR) of −0.0164 °C⁻¹ was measured, indicating the device’s capability for accurate temperature sensing. Additionally, a temperature exceeding 37 °C was achieved with a power consumption of approximately 50 mW. This work presents a robust method for passivating and transferring electronics for on-skin applications. Full article

Phosphate (Pi) is a vital macronutrient for plant growth and development, and precise monitoring of its cellular dynamics is essential to understanding Pi homeostasis and its interaction with stress responses. Genetically encoded FRET-based biosensors such as FLIPPi enable real-time, non-invasive visualization of cytosolic Pi levels in living tissues. In this study, Arabidopsis and rice lines expressing a FLIPPi biosensor were used to monitor cytosolic Pi dynamics in root epidermal cells. Sensor functionality was confirmed by measuring FRET responses to graded Pi supplies, revealing a consistent reduction in FRET ratios with increasing Pi concentrations, reflecting elevated cytosolic Pi levels. Comparisons with a Pi-insensitive FLIPPi variant confirmed the specificity of the observed changes. Furthermore, live imaging demonstrated rapid and dynamic alterations in cytosolic Pi upon treatment with defense-related hormones and elicitors of immune responses supporting a link between Pi signaling and plant immunity. Finally, the application of phosphite, an analog of Pi, altered Pi dynamics in both Arabidopsis and rice, suggesting an interference with Pi accumulation. Collectively, our findings establish FLIPPi as a reliable tool for in vivo monitoring of Pi in Arabidopsis and rice plants, the model systems for studies in dicotyledonous and monocotyledonous species, respectively. Full article

This study presents a comparative investigation of plasmonic sensing platforms based on colloidal gold nanoparticle (AuNP) suspensions and gold film over nanosphere (AuFoN) solid substrates for the detection of epidermal growth factor receptor (EGFR), an essential biomarker and therapeutic target in oncology. The strategy relies on fluorescence emission modulation of an Atto647N-labeled DNA oligomer competitively bound to an EGFR-specific aptamer. Our results demonstrate that the colloidal AuNPs can function as competitive binding sensors, leading to fluorescence quenching upon fluorophore attachment to the surface of the NPs and partial fluorescence recovery due to EGFR-induced displacement of the fluorophore–aptamer complex. This specificity was confirmed by reversed binding experiments. However, the system proved highly sensitive to the experimental design: excessive washing (centrifugation) led to unspecific aggregation and signal loss, while reduced washing steps improved signal retention and revealed EGFR-induced fluorophore displacement into the supernatant. On the contrary, film-based substrates exhibited strong initial fluorescence, but failed to retain the fluorophore–aptamer complex after washing, resulting in fluorescence decay independent of EGFR incubation. This indicates that AuFoN lacked the binding stability necessary for specific displacement-based sensing. These findings highlight that while colloidal AuNPs can support competitive binding detection, their reproducibility is limited by colloidal stability and protocol sensitivity, whereas AuFoN substrates require improved surface functionalization strategies. The study emphasizes the critical role of surface chemistry, aptamer–fluorophore affinity, and washing protocols in determining the success or failure of plasmon-enhanced aptamer-based biosensing systems and suggests opportunities for improving specificity and robustness in future designs. Full article

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease, characterized by pruritic and eczematous lesions. Skin barrier dysfunction and aberrant inflammatory responses are hallmark features of AD. Recent genome-wide association studies have implicated NLRP10, a unique member of the NOD-like receptors (NLRs) lacking a leucine-rich repeat (LRR) domain, in AD susceptibility. Unlike other NLRs, the physiological role of NLRP10 in skin remains incompletely understood. Emerging evidence shows that NLRP10 regulates keratinocyte survival and differentiation, acts as a molecular sensor for mitochondrial damage, enhances anti-microbial response and contributes to skin barrier function. This review summarizes current insights into NLRP10′s functions in skin homeostasis, its interplay with cell death pathways, and its role in maintaining skin barrier function. Furthermore, therapeutic opportunities to target NLRP10 as a novel strategy for modulating epidermal cell death and restoring barrier function in AD are highlighted. Full article

Phosphoinositide-binding pleckstrin homology (PH) domains interact with both phospholipids and proteins, often complicating their use as specific lipid biosensors. In this study, we introduced specific mutations into the phosphatidylinositol 3,4,5-trisphosphate (PIP₃)-specific PH domains of protein kinase B (Akt) and general receptor for phosphoinositides 1 (GRP1) that disrupt protein-mediated interactions while preserving lipid binding, in order to enhance biosensor specificity for PIP₃, and evaluated their impact on plasma membrane (PM) localization and lipid-tracking ability. Using bioluminescence resonance energy transfer (BRET) and confocal microscopy, we assessed the localization of PH domains in HEK293A cells under different conditions. While Akt-PH mutants showed minimal deviations from the wild type, GRP1-PH mutants exhibited significantly reduced PM localization both at baseline and after stimulation with epidermal growth factor (EGF), insulin, or vanadate. We further developed tandem mutant GRP1-PH domain constructs to enhance PM PIP₃ avidity. Additionally, our investigation into the influence of ADP ribosylation factor 6 (Arf6) activity on GRP1-PH-based biosensors revealed that while the wild-type sensors were Arf6- dependent, the mutants operated independently of Arf6 activity level. These optimized GRP1-PH constructs provide a refined biosensor system for accurate and selective detection of dynamic PIP₃ signaling, expanding the toolkit for dissecting phosphoinositide-mediated pathways. Full article

In clinical applications of surface-enhanced Raman spectroscopy (SERS) immunosensors, accurately determining analyte biomarker concentrations is essential. This study presents a non-invasive approach for quantifying various breast cancer biomarkers—including human epidermal growth factor receptor II (HER-II) (2+, 3+ (I), 3+ (II), 3+ (III), and positive IV) and CA 15-3—using a directional, plasmonically active, label-free SERS sensor. Each stage of sensor functionalization, conjugation, and biomarker interaction was verified by UV–Vis spectroscopy. Atomic force microscopy (AFM) characterized the morphology of gold nanourchin (GNU)-immobilized printed circuit board (PCB) substrates. An enhancement factor of ≈ 0.5 × 10⁵ was achieved using Rhodamine 6G as the probe molecule. Calibration curves were initially established using standard HER-II solutions at concentrations ranging from 1 to 100 ng/mL and CA 15-3 at concentrations from 10 to 100 U/mL. The SERS signal intensities in the 620–720 nm region were plotted against concentration, yielding linear sensitivity with R² values of 0.942 and 0.800 for HER-II and CA15-3, respectively. The same procedure was applied to breast cancer serum (BCS) samples, allowing unknown biomarker concentrations to be determined based on the corresponding calibration curves. SERS data were processed using the filtfilt filter from scipy.signal for smoothing and then baseline-corrected with the Improved Asymmetric Least Squares (IASLS) algorithm from the pybaselines.Whittaker library. Principal Component Analysis (PCA) effectively distinguished the sample groups and revealed spectral differences before and after biomarker interactions. Key Raman peaks were attributed to functional groups including N–H (primary and secondary amines), C–H antisymmetric stretching, C–N (amines), C=O antisymmetric stretching, NH₃⁺ (amines), carbohydrates, glycine, alanine, amides III, C=N stretches, and NH₂ in primary amides. Full article

Intrinsic conductive ionic hydrogels, endowed with excellent mechanical properties, hold significant promise for applications in wearable and implantable electronics. However, the complexity of exercise and athletics calls for mechanical tunability, facile processability and high conductivity of wearable sensors, which remains a persistent challenge. In this study, we developed a mechanically tunable and high ionic conductive hydrogel patch to approach multi-gesture or motion monitoring. Through adjustment of the ratio of amino trimethylene phosphonic acid (ATMP) and poly(vinyl alcohol) (PVA), the composite hydrogel attains tunable mechanical strength (varying from 50 kPa to 730 kPa), remarkable stretchability (reaching up to 1900% strain), high conductivity (measuring 15.43 S/m), and strong linear sensitivity (with a gauge factor of 2.34 within 100% strain). Benefitting with the tunable mechanical sensitivity, the composite hydrogel patch can perform subtle movement monitoring, such as epidermal pulses or pronounced muscle vibrations; meanwhile, it can also recognize and detect major motions, such as hand gestures. The mechanically tunable composite hydrogel contributes a versatile sensing platform for health or athletic monitoring, with wide and sensitive adoptability. Full article

Epidermal sensors are pivotal components of next-generation wearable technologies. They offer transformative potential in health monitoring, motion tracking, and biomedical applications. This potential stems from their ultra-thin design, skin compatibility, and ability to continuously detect physiological signals. The long-term functionality relies on advanced power systems balancing flexibility, energy density, and environmental resilience. This review highlights four key power strategies: chemical batteries, biofuel cells, environmental energy harvesters, and wireless power transfer. Breakthroughs in multidimensional materials address challenges in ion transport, catalytic stability, and mechanical durability. Structural innovations mitigate issues like dendrite growth and enzyme degradation. These systems enable applications spanning biomarker analysis, motion sensing, and environmental monitoring. By integrating these advancements, this review concludes with a prospective outlook on future directions for epidermal sensor power systems. Full article

Background/Objectives: Extracellular vesicles (EVs) are nanoscale, membrane-enclosed structures that play key roles in intercellular communication and biological regulation. Among them, Lactobacillus paracasei-derived EVs (Lp-EVs) have attracted attention for their anti-inflammatory and anti-aging properties, making them promising candidates for therapeutic and cosmetic use. However, methods for specific detection and quantitative evaluation of Lp-EVs are still limited. This study aims to develop a surface plasmon resonance (SPR)-based sensor system for the precise and selective detection of Lp-EVs. Methods: Anti-p40 antibodies were immobilized on gold thin films to construct an SPR sensing platform. The overexpression of the p40 protein on Lp-EVs was confirmed using flow cytometry and Western blotting. For functional evaluation, Lp-EVs were applied to an artificial skin membrane mounted on a Franz diffusion cell, followed by SPR-based quantification and fluorescence imaging to assess their skin penetration behavior. Results: The developed SPR sensor demonstrated high specificity and a detection limit of 0.12 µg/mL, with a linear response range from 0.1 to 0.375 µg/mL. It successfully discriminated Lp-EVs from other bacterial EVs. In the skin diffusion assay, Lp-EVs accumulated predominantly in the epidermal layer without penetrating into the dermis, likely due to their negative surface charge and interaction with the hydrophobic epidermal lipid matrix. Fluorescence imaging confirmed this epidermal confinement, which increased over 24 h. Conclusions: This study presents a sensitive and selective SPR-based platform for detecting Lp-EVs and demonstrates their potential for targeted epidermal delivery. These findings support the use of Lp-EVs in skin-focused therapeutic and cosmetic applications. Future studies will explore strategies such as microneedle-assisted delivery to enhance transdermal penetration and efficacy. Full article

In this paper, peanut protein (PP) was used as the sole raw material for the preparation of fluorescent carbon dots (PP-CDs) by hydrothermal method. The PP-CDs exhibit good dispersibility, spherical-like shapes, and uniform sizes; the average particle size of the PP-CDs was 3.18 ± 0.17 nm. The Fourier transform infrared spectroscopy (FTIR) results show that the surface of PP-CDs is rich in hydrophilic groups such as hydroxyl, carboxyl and amide groups. The PP-CDs exhibit good fluorescence emission properties and excitation wavelength dependence, with the optimal excitation wavelength and emission wavelength at 348 nm and 452 nm, respectively. According to the fluorescence quenching effect of metronidazole (MTZ) and tinidazole (TDZ) on PP-CDs, a highly linear fluorescence sensor was established, with a concentration range of 0.10–60.0 µM, and the detection limits of MTZ and TDZ are 32.0 nM and 48.0 nM, respectively. The result of CCK-8 test and imaging of HepG-2 cells and onion epidermal cells reveal that PP-CDs have good membrane permeability, biocompatibility and imaging ability. Full article

Strawberry fruits accumulate nutritionally critical anthocyanins and phytochemicals through light=quality-dependent metabolic regulation. This review systematically examines spectral modulation strategies for enhancing anthocyanin biosynthesis and fruit quality parameters. We demonstrate that dual red (660 nm) and blue (450 nm) irradiation optimally activates the flavonoid pathway, co-upregulating structural genes (CHS, F3H, DFR, ANS) and regulatory factors (FaMYB10, FaHY5). Mechanistic analyses reveal that blue light preferentially induces upstream phenylpropanoid enzymes (PAL, C4H, CHI), while red light enhances proanthocyanidin production through differential induction of LAR and ANR. Strategic supplementation with UV-C (254 nm, 1–2 kJ/m²/d) and far-red (730 nm, 15 μmol·m⁻²·s⁻¹) improves anthocyanin spatial distribution via stress-mediated epidermal accumulation. Spectral optimization further coordinates flavor development by (1) balancing sucrose–hexose ratios through FaSPS1 modulation, (2) reducing organic acid content via FaMYB44.2 suppression, and (3) amplifying volatile esters (e.g., methyl anthranilate) through SAAT induction. Postharvest UV-C treatment (4 kJ/m²) extends shelf life by 30–35% through microbial inhibition and antioxidant system activation. Practical implementation frameworks propose phase-specific LED protocols related to vegetative growth (R:B = 3:1), flowering (R:B = 1:1), and maturation (R:B = 4:1) stages integrated with environmental sensors in controlled agriculture systems. These findings establish an actionable paradigm for photonic crop management, synergizing molecular precision with commercial horticultural operations to achieve sustainable yield enhancement (projected 22–28% increase) and nutraceutical enrichment. Full article

Epidermal electronics provide a promising solution to key challenges in wearable electronics, such as motion artifacts and low signal-to-noise ratios caused by an imperfect sensor–skin interface. To achieve the optimal performance, skin-worn electronics require high conductivity, flexibility, stability, and biocompatibility. Herein, we present a nontoxic, waterborne conductive ink made of silver and child-safe slime for the fabrication of skin-compatible electronics. The ink formulation includes polyvinyl acetate (PVAc), known as school glue, as a matrix, glyceryl triacetate (GTA) as a plasticizer, sodium tetraborate (Borax) as a crosslinker, and silver (Ag) flakes as the conducting material. Substituting citric acid (CA) for GTA enhances the deformability by more than 100%. With exceptional conductivity (up to 1.17 × 10⁴ S/cm), we demonstrate the ink’s potential in applications such as an epidermal near-field communication (NFC) antenna patch and a wireless ECG system for motion monitoring. Full article

Wearable technology has advanced significantly, offering real-time monitoring of athletes’ physiological parameters and optimizing training and recovery strategies. Recent developments focus on biosensor devices capable of monitoring biochemical parameters in addition to physiological ones. These devices employ noninvasive methods such as sweat analysis, which reveals critical biomarkers like glucose, lactate, electrolytes, pH, and cortisol. These biomarkers provide valuable insights into an athlete’s energy use, hydration status, muscle function, and stress levels. Current technologies utilize both electrochemical and colorimetric methods for sweat analysis, with electrochemical methods providing higher precision despite potential signal interference. Wearable devices such as epidermal patches, temporary tattoos, and fabric-based sensors are preferred for their flexibility and unobtrusive nature compared to more rigid conventional wearables. Such devices leverage advanced materials and transmit real-time data to computers, tablets, or smartphones. These data would aid coaches and sports medical personnel in monitoring athletes’ health, optimizing diets, and developing training plans to enhance performance and reduce injuries. Full article