Extracellular vesicles (EVs) produced by stem cells are nanoscale carriers of bioactive compounds with regenerative and immunomodulatory capabilities similar to those of their parent cells. Their therapeutic potential outperforms traditional stem cell therapies by lowering hazards such tumorigenicity and allowing for precise delivery. To provide a high-efficiency platform for selectively isolating stem cell EVs from minimal serum quantities while overcoming the constraints of traditional approaches such as ultracentrifugation, we developed an immunoaffinity-based capture system utilizing SiO2 wafers functionalized with gold nanoparticles (GNPs), polyethylene glycol (HS-PEG-COOH), and stem cell-specific antibodies. The platform was evaluated to isolate EVs from $20~\mu $ L serum samples. The technique efficiently and selectively isolates EVs, including stem cell-derived subtypes, with yields of up to $10^{8}$ particles. Western blot testing demonstrated high purity and low protein contamination, demonstrating the capture mechanism's selectivity. This nanoparticle-enhanced platform allows for scalable, high-purity EV extraction from small sample volumes, which aids in downstream molecular analysis and therapeutic development. Its capacity to distinguish across EV subtypes has potential in personalized medicine, regenerative therapies, and non-invasive diagnostics.

Severe hypoxic conditions cause systemic physiological stress, highlighting the need for non-invasive health monitoring. Urinary extracellular vesicles (uEVs) contain stable, hypoxia-responsive biomarkers like Mucin-1 (MUC1) and Mucin-5AC (MUC5AC). We introduce a compact, label-free electrochemical impedance spectroscopy (EIS) biosensor with reagent-free electric field (EF) lysis method. A 30-second square wave (50 mV,1 kHz) applied directly to urine quickly breaks down uEV lipid membranes, releasing intravesicular content efficiently. Validated with ELISA, this physical on-chip lysis yields a 3.06-fold increase in biomarker recovery compared to untreated samples without denaturing chemicals. The sensor was tested with urine samples taken before and after a 10 day high-altitude (14,860 ft) hypoxic challenge. The dual-biomarker system detected significant, individual increases post-hypoxia ranging from 54.7% to 526.1% for EV-MUC5AC and 60.9% to 127.4% for EV-MUC1. By bypassing traditional isolation and extraction processes, this platform reduces workflow time by about 95%, offering a rapid, highly sensitive point-of-care method for real-time monitoring of physiological stress in extreme environments.

Research on metal oxide-based sensors has produced nanomaterials with high response and stability; however, these sensors have a drawback of cross-sensitivity which limits their deployment in practical sensors. In contrast to the conventional CuO-In₂O₃ layer reported previously, the present work investigates the heterojunction with a charge accumulation layer and defect states for selective CH₄ detection. The novelty of the work lies in the synergistic integration of a Pd-doped CuO-In₂O₃ heterojunction with opto-thermal activation studies, further establishing a correlation between heterojunction, induced band modulation, defect states, and CH₄ sensing performance. The optimized sensor showed a sensitivity of 71% towards 1 ppm of CH₄, at an operating temperature of 200°C, with a rise time of 54s and a fall time of 38s. The prototype of an optimized sensor has been developed by integrating the selective sensing layer to the fabricated sensing platform. The work also provides insights into The study also demonstrates wavelength-dependent photoactivation behaviour and provides insight into the heterojunction band alignment, presence of defect states, and photogenerated charge carriers. Therefore, the key contribution of this work is the development of an integrated thermo-opto activated CuO–In₂O₃ heterostructure and platform, which enables enhanced CH4 sensing, while providing fundamental insight into the interplay between heterojunction effects, oxygen vacancies, and wavelength-selective optical excitation.

We introduce silicon dioxide (SiO2) wafer-assisted technology for the isolation and quantification of extracellular vesicle (EV) biomarkers utilizing electrochemical impedance spectroscopy (EIS). Traditional EVs isolation techniques, including ultracentrifugation and precipitation, are laborious and have inconsistent recovery rates. This study involved the synthesis of gold nanoparticles (GNPs), which were subsequently deposited onto SiO2 wafers. Subsequently, the surface was functionalized with polyethylene glycol and activated using EDC/NHS chemistry to improve biomolecular binding. Approximately 6.8 x 10(8) EVs particles were effectively extracted from 200 mu L of serum samples utilizing the GNP-coated silicon substrate, representing a significant portion of the expected similar to 2 x 10(9) EVs typically present in such a volume. After immobilization, EVs were lysed directly on the surface using Triton X-100, and the lysis duration was optimized using Western blot analysis. The resultant lysate underwent EIS to assess variations in charge-transfer resistance (R-CT), facilitating the precise identification of target proteins. The impedance response exhibited a concentration-dependent increase in R-CT, with a detection limit of 1.206 pg/mL and a linear range of 62.5-2000 pg/mL. The results were confirmed by enzyme-linked immunosorbent assay, affirming the reliability and specificity of the electrochemical platform. This integrated isolation-lysing system offers a scalable and effective approach for EVs isolation and protein extraction. The proposed technique, in conjunction with the sensing platform, can be utilized in point-of-care diagnostics and liquid biopsy-based cancer detection.

Extracellular vesicles (EVs) are emerging as valuable biomarkers for liquid biopsy because they reflect the molecular composition of their originating cells and play a key role in intercellular communication. However, most EV-based analytical workflows rely on multistep isolation and chemical lysis procedures, which increase processing complexity, time, and contamination risks. Here, we introduce a simplified, isolation and reagent free, strategy for rapid quantification of EV-derived lung cancer biomarkers by electric field (EF)-mediated EV lysis method to directly break down EVs in serum, followed by label-free detection of lung cancer with non-faradaic electrochemical impedance spectroscopy (N-EIS). Systematic optimization of waveform shapes (sine, square, and sawtooth), frequencies (10 Hz to 100 kHz), and voltages (50 mV to 1 V) shows that a low-voltage (50 mV) square-wave signal at 1 kHz is optimal for EV electropermeabilization while maintaining encapsulated biomarkers. The efficacy of EF-induced EV lysis was validated by ELISA-based quantification of EV-derived lung cancer-associated proteins. The proposed workflow eliminates the need for labor-intensive isolation and chemical reagents, achieving a detection time of 30 min. The proposed platform achieved high sensitivity (> 80%) on antibody functionalized screen-printed gold electrode, with limit of detection of 0.28 pg mL(-)& sup1; (TSG101), 0.56 pg mL(-)& sup1; (GM2AP), 7.38 pg mL(-)& sup1; (MUC1) and 0.42 pg mL(-)& sup1; (EGFR). Clinical evaluation using human serum successfully discriminated between healthy individuals and lung cancer patients with high statistical confidence. These results highlight the potential of EF-assisted N-EIS as a robust liquid biopsy tool, offering a scalable pathway toward portable diagnostic systems for decentralized oncological screening and non-invasive monitoring of early-stage disease.

We introduce the EV-Disrupt and Detect System (EDDS), an innovative, portable biosensor utilizing electrochemical impedance spectroscopy (EIS) for the swift, low-volume, and economical assessment of extracellular vesicle (EVs)-related lung cancer biomarkers. The EDDS combines electric field-induced EVs disruption with the simultaneous detection of 4 critical biomarkers: TSG101, EGFR, GPC1, and GM2AP, directly from serum. EVs disruption occurred within 30 seconds utilizing a 50 mV, 1 kHz square wave, with disruption efficiency validated by nanoparticle tracking analysis (93.9%) and Western blotting to ensure protein integrity. Post-disruption, the released cargo was quantified by electrochemical impedance spectroscopy (EIS) across 4 specialized screen-printed electrodes (SPEs), with results corroborated by enzyme-linked immunosorbent test (ELISA). The electric field parameters (voltage, frequency, and duration) were optimized with $150~\mu $ L of serum, yielding a 0.218-2.809-fold enhancement in detectable biomarker concentrations. The EDDS markedly decreases processing time, cost, and technological complexity by obviating the necessity for traditional EVs isolation techniques such as ultracentrifugation or chromatography. This integrated platform facilitates direct EVs disruption and multiplexed biomarker identification within a singular workflow, providing a robust instrument for minimally invasive cancer diagnostics and advancing broader clinical applications in liquid biopsy.

Extracellular vesicles (EVs) that contain human epidermal growth factor receptor 2 (HER2) biomarkers are released by both healthy and cancerous cells, presenting substantial potential for the precise detection of numerous disorders, including cancer. To accurately quantify proteins, EVs must initially be separated from serum and then lysed to extract their protein content. Although ultracentrifugation is the predominant isolation technique, it has constraints regarding scalability and repeatability. Furthermore, traditional detergent-based lysis techniques endanger protein stability. This study introduces an innovative method for EV isolation utilizing colloidal gold nanoparticles, succeeded by lysis through sinusoidal electrical stimulation. A nonFaradaic electrochemical impedance spectroscopy (EIS) system has been developed utilizing screen-printed electrodes for determining HER2 protein levels. EV isolation was confirmed via western blotting for the EV-associated markers CD63 and HSP70. To promote the lysis of EVs, the EV sample was exposed to sine wave signals of differing amplitudes, with optimal disruption noted between 100 mV and 500 mV. The lysate was examined via EIS, producing a linear behavior from 5 mu g/mL to 0.05 ng/mL with a limit of quantification of 0.109 mu g/mL in human serum. The developed platform thus proves suitable for quantifying the HER2 protein from breast cancer patients.

Chemiresistive VOC sensors are becoming increasingly used in healthcare due to their inexpensive cost and ease of production. TiO2/WO3 nanocomposites that were optically activated and microwave-treated were used to target isoprene, a combinational biomarker for respiratory and cardiovascular disorders. Distinct chemiresistive responses under varying activation energies were analyzed via scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). A power-law model that was realized in conjunction with I–V measurements and the device characteristics obtained via STM is used to estimate the concentrations of photogenerated carriers in the air and isoprene environments. This work advances the design of VOC sensors for biological applications by providing crucial nanoscale insights into the sensing mechanism and providing a unique quantification of carrier behaviour under oxygen and isoprene adsorption.

Metal oxide-based gas sensors often suffer from baseline drift and selectivity. Software-based algorithms are usually used to correct errors arising from the drift phenomenon. However, the error probability will decrease if the drift can be nullified or minimized from the experimental part. This article has conducted a detailed study to nullify the baseline drift of In2O3-based CH4 sensors by employing prolonged heating at 250 degrees C with activation techniques. The baseline drift of the sensor was reduced to less than 1% by the technique of dual activation. The device was tested for selective sensing of CH4 and its stability was investigated. The device reproduced the same baseline after multiple cycles of operation.

Metal Oxide Semiconductor based Microgas Sensors are widely employed for detecting even a trace amount of gas, with widespread applications in detection of poisonous gases for environmental monitoring and biomedical fields. Sensing layers in microgas sensors can be suitably optimized to detect target gases. Metal Oxide Semiconductors (MOS) is a sensitive structure for gas sensing due to its superior performances. A microheating layer with an interdigitated electrode (IDE) is useful to excite and activate the sensing layer. In this work, the scope of Finite Elemental Analysis (FEA) is explored to analyse the electrical and thermal performance of the electrode and heater layers, while experimental validation ensures its accuracy. The sensitivity of the methane gas sensor was found to be optimal at $300^{\circ} \mathrm{C}$, with a maximum sensitivity of $65 \%$. The sensor exhibits high sensitivity, saturation and recovery, making it an efficient tool for sensing applications. The simulation of in-plane microheater with interdigitated electrodes is performed using the software COMSOL Multiphysics.

Titanium carbide (Ti3C2), a 2-D material discovered in 2011, has been investigated for various applications, and is to its potential as a gas sensor is exploring widely. However, to serve effectively in the field of gas sensing, it is essential to ensure long-term stability, which involves maintaining a consistent and repeatable output over time. Multiple studies have observed the degradation of MXene, particularly the surface oxidation of Ti3C2 to TiO2 in the presence of moisture, highlighting the necessity of in-depth research in this field. This work primarily focused on the stability analysis of MXene-based gas sensors. Additionally, we demonstrated that 2-D layered carbon/TiO2 (C/TiO2) structures synthesized via controlled surface oxidation of Ti3C2TX MXene at 500 C-degrees are stable as a gas sensor and can effectively detect hydrogen at low ppm levels. By utilizing this approach, the sensor achieved a remarkable response of 93% (in 65% relative humidity), with a response time of 45 s and a recovery time of 20 s at 300 C-degrees operating temperature. Furthermore, the selectivity of the prepared sample is compared with 100-ppm CO, 250-ppm NH3, and 10000-ppm CH4, indicating that oxidized MXene is a promising candidate for real-time H-2 sensing. This excellent selectivity and significant sensor response to H-2 make it well-suited for leak-detection applications. An attempt was also made to correlate the stable hydrogen sensing mechanism with the help of material characterization, which suggests that the oxidation of Ti3C2Tx MXene to C/TiO2 leads to the formation of porous, high-surface-area nanostructure, which enhances gas adsorption and desorption.

A highly efficient gas sensor is characterized by strong selectivity, quick response time and the ability to operate at room temperature. Transition metal dichalcogenides (TMDs) represents a family of two-dimensional materials with excellent electronic, chemical and optical properties. 2D materials are characterized by their unique structure, in which atoms are covalently bonded within thin sheets, while van der Waals forces hold these sheets together. Their high surface-to-volume ratio exposes more atoms, facilitating interactions with the surrounding environment. The modification of TMDs by metal oxide doping can improve their performance in gas sensing applications. In this work, we have selected PdSe2, a transition metal dichalcogenide doped with ZnO, a semiconducting metal oxide for making a highly selective room temperature hydrogen gas sensor with a sensing response of 34.45%.

Exosomes that contain TSG101 biomarkers are synthesized by both healthy and malignant cells and have the potential to accurately diagnose a wide range of diseases, including cancer. For exosomal protein quantification, exosomes must be isolated from serum and then used for protein extraction. Ultracentrifugation is the most common way to isolate. Although detergents are commonly employed to extract the encapsulated exosomal proteins, they may compromise their protein integrity. The present work involves two detailed studies: the lysing of exosomes immobilized on the Au screen printed electrode (SPE) and the development of a nonfaradaic electrochemical sensor by utilizing SPE to quantity TSG101 protein. To lyse exosomes attached to the SPE surface, we applied different amplitudes of square signals to the SPE to disrupt the exosomes and facilitate the release of their contents. The lysate solution was utilized for electrochemical impedance spectroscopy (EIS) by faradic and nonfaradic techniques. Results of both types of EIS were similar, showing that nonfaradaic sensing could be an effective alternative. Hence, we employed nonfaradaic EIS to quantify the TSG101 protein released by electric lysis and validated the result with ELISA. We achieved a linear response, specifically at concentrations ranging from 0.125 to 8 ng/mL, with a detection limit of 0.10 ng/mL for human serum. Cross-reactivity analysis demonstrated selectivity to TSG101 with minimal interaction with nonspecific biomolecules.

Exosomes are essential for facilitating intercellular communication. The importance of these molecules lies in the fact that they can transport bioactive molecules across cells, influencing critical physiological processes such as immune responses, tissue repair, and cell proliferation. In addition to their physiological roles, exosomes are also involved in various pathological conditions, including carcinoma, respiratory, neurodegeneration and cardiovascular diseases. They can convey signals that may promote tumor growth, metastasis, or immune evasion in cancer. This study suggests a unique scalable platform for effective exosome isolation based on functionalised SiO2 wafers. Gold nanoparticles (GNPs) with diameters of 20 nm and 60 nm were synthesized and deposited on SiO2 wafers before being PEGylated and conjugated with antibodies. The platform successfully isolated exosomes employing antibodies against CD9, CD81, and CD63, with CD63-coated wafers providing the most exosomes, in accordance with their abundance on the exosomal surface. NTA revealed the presence of exosomes. A 1 cm x 1 cm SiO2 wafers successfully isolated 3.3 x 108 exosomes from 100 µL serum. A 2 cm x 2 cm wafer demonstrated a significant increase in isolation efficiency, capturing 7.2 x 108 exosomes from 200 µL serum, highlighting the scalability and potential for high-throughput exosome isolation using this platform. The average size of isolated exosomes ranged from 40 to 150 nm. This scalable technology offers a promising alternative to ultracentrifugation for exosome isolation. It has potential uses in the delivery of drugs and other biomedical fields.Clinical Relevance— This work enables scalable exosome isolation, critical for advancing therapies in drug delivery, neurodegenerative diseases, cancer, and regenerative medicine.

Glypican1 and mucin1 antigens are prominent biomarkers for the prognosis and diagnosis of pancreatic cancer. Their presence within the extracellular vesicles (EVs) opens the possibilities for oncology care through the development of minimally invasive biomarker-assisted screening tools. Traditionally, EV antigen quantification relies on ultracentrifugation (UC) and chemical lysis, which are time-consuming, equipment-dependent, and often compromise EV integrity, damaging surface intact biomarkers. This study integrates EV isolation and electric field (EF) lysis into a unified platform. The lysates were then analyzed using an electrochemical impedance spectroscopy (EIS)-based sensor to detect glypican-1 (GPC1) and mucin-1 (MUC1). ELISA confirms the EF lysis of the immobilized EV and shows an increase in the antigen concentration by 2.5 times (compared to the pre-lysed sample). Hence, EF lysis makes the sensor more sensitive than traditional methods. To enhance the electric lysis process, we applied varying voltages of a sinusoidal signal to the screen printed gold electrode (SPGE)-immobilized EVs. The lysate was subsequently used to quantify the GPC1 and MUC1 antigens through EIS. The results indicate that a 50-mV sinusoidal signal is sufficient to effectively lyse EVs, confirmed by western blotting. The nanoparticle tracking analyzer (NTA) results showed the successful isolation of 10(9) EVs from 100 mu L of serum using CD63 antibody. The developed EIS sensor can detect GPC1 and MUC1 with an LOD of 0.053 and 0.033 pg/mL, respectively, from EV lysate, showing minimal nonspecific binding in the negative control. Beyond GPC1 and MUC1, the approach is adaptable for detecting other EV-associated biomarkers, enabling broader applications in early cancer detection and disease monitoring.

Titanium carbide (Ti3C2T X ), a member of the MXene family, is widely used in diverse applications, which include gas sensors, energy storage, electrochromic devices, biosensors, etc. However, its effectiveness in gas sensing is notably lacking, indicating the need for further research in this field. This study investigates a detailed analysis of the effects of annealing on pristine titanium carbide, particularly emphasizing its ability to detect H2 selectively. Annealing Ti3C2T X at 300 degrees C in the presence of air results in the formation of partially oxidized MXene (Ti3C2T X /TiO2), which enhances conductivity and yields a response of 62 +/- 5% to 4% H2 and 6.6% to 50 ppm of H2, with a response time of less than 1 min. In contrast, pure Ti3C2T X shows a reduced conductivity and a weak response of 1.0%. The 300 degrees C annealed MXene sensor, with its operating temperature optimized at 300 degrees C, exhibits a strong selectivity toward H2 compared to CH4, NH3, and CO due to the combined properties of MXene and TiO2. In addition, the instability issues within the pristine MXene contribute to its diminished sensitivity, and an effective enhancement can be realized through variation of the annealing temperatures. A detailed investigation was carried out to understand the underlying mechanisms influencing gas sensing in partially oxidized MXene, emphasizing structure-based depletion layer formation using detailed material characterization techniques, including X-ray photoelectron spectroscopy, thermogravimetric analysis, and X-ray diffraction. Finally, the sensor prototype is assembled by combining a microheater and an interdigitated electrode with the optimized sensing material inside the TO8 package.

A simple, inexpensive method to detect sodium ions from aqueous solutions is reported in this paper. The method of detection based on transmittance changes observed in tungsten oxide films on.

In this work, a detailed study has been carried out to understand the gasochromic properties of tungsten oxide at different operating temperatures, sol (low, medium, high), and doping concentrations. Similarly, the hydrogen sensing results are corroborated with material characterization to get more insight into the gasochromic performance of the prepared samples. In addition to this, the effect of noble metal (Pt, Pd) doping on the gasochromic performance has been discussed with a focus on X-ray photoelectron spectroscopy (XPS) and Raman studies, which is lacking in the literature. The Pt- and Pd-doped tungsten oxide thin films were prepared by the sol–gel method and spin-coated onto glass substrates. A detailed Raman spectroscopy of the samples reveals tungsten’s coexistence in monoclinic crystalline and hydrous phases. The surface morphology and chemical compositions of the samples were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and XPS. The ultra violet-visible-near infra-red (UV–VIS–NIR) transmittance results show that gasochromic response increases significantly with an increase in operating temperature. Pt-doped sample prepared from moderate sol concentration exhibited a higher transmittance change of 22% for 4% hydrogen purge at an operating temperature of 70 °C. The response and recovery times measured were less than 40 s. Pt-doped samples showed better gasochromic response than Pd-doped samples due to higher catalytic activity of PtO:Pt compared to PdO:Pd. The sample had a lower detection limit of 0.01% at temperatures between 50 °C and 100 °C and did not show any cross sensitivity toward other gases.