Advanced Sensor Research最新文献

While nitric oxide (NO) release from polyurethane (PU) sensor membranes has shown promise as a foreign body response (FBR) mitigation strategy to enhance the performance of implantable glucose sensors, its utility is ultimately limited by release duration. Further improvement is envisioned by combining electrospun fibers with NO release. Electrospinning process parameters that produce average fiber diameters of 670 and 1460 nm as the outer membrane of NO-releasing glucose sensors, are developed to not impact NO-release or sensor performance. An in vivo evaluation in a diabetic porcine model demonstrates a reduced inflammatory response for 670 versus 1460 nm fibers. This benefit appears to continue with a robust pro-wound healing response beyond the NO-release duration. At short periods (i.e., 11-d post-implantation), FBR mitigation is attributed to NO release and not the presence of fibers. Still, no negative effects are observed with the 670 nm fibers in this acute phase of the FBR. Taken together, the tissue response data demonstrate 670 nm fibers as a promising long-term FBR mitigation strategy.

Immunotherapy has revolutionized cancer treatment, with Chimeric Antigen Receptor (CAR) T-cell therapy emerging as a highly effective approach for, e.g., hematological malignancies. However, the complexity of this living drug necessitates efficient methods to ensure the identity of the engineered cells during manufacturing and post-infusion therapy monitoring. In this study, a proof-of-concept is presented using a silicon nanowire field-effect transistor (SiNW FET) nanosensing platform capable of label-free, real-time identification and quantification of CAR T-cells at single-cell resolution. The nanosensor's functionalized surface mimics tumor antigens, enabling selective interaction with CAR-expressing cells. This platform demonstrates exceptional specificity by distinguishing CAR T-cells from wild-type T-cells and quantifying cell populations with ultrasensitivity. These results establish the SiNW FET nanosensing platform as a promising tool for streamlining CAR T-cell manufacturing and post-treatment monitoring, improving quality assurance, and advancing clinical applications in immunotherapy.

Freon refrigerants, whose leakage will cause serious safety and environmental issues, have an urgent need of developing leakage detection technologies. Conventional metal oxide semiconductor (MOS) gas sensors exhibit limited efficacy in detecting halogenated Freons due to their chemical inertness and weak charge-transfer interactions. While recent innovations employing mesoporous γ-Al₂O₃ overlayers have enabled Freon detection via catalytic decomposition sensing mechanism, the achieved sensing performance remains suboptimal. In this work, this issue is addressed by engineering a Pd-doped mesoporous γ-Al₂O₃/SnO₂ (Pd-γ-Al₂O₃/SnO₂) gas sensor. The doped Pd atoms not only accelerate the decomposition of Freon molecules on the catalytic layer but also induce the Schottky-barrier effect in the SnO₂ sensing layer. Benefiting from the synergistic effect, the Pd-γ-Al₂O₃/SnO₂ gas sensor shows outstanding response, good stability, repeatability, selectivity, and rarely-reported universality in sensing different Freon gases. Notably, a valuable solution is demonstrated in the leakage detection of next-generation refrigerants, Freon R1234yf. The sensing mechanism is deduced by exhaust gas components identification. These results highlight the promising potential for addressing the real-world needs of Freon refrigerant leakage detection technology.

This work presents a screen-printed carbon electrode (SPCE) modified with iron oxide nanoparticles-reduced graphene oxide (ION-rGO) nanocomposite for the rapid and highly sensitive determination of nitrite in real water samples. The presence of both ION and rGO on the electrode surface enhances the sensing performance compared to the unmodified SPCE by reducing the charge transfer at the electrode/electrolyte interface. Under optimized conditions, it is demonstrated that the charge-transfer resistance determined from electrochemical impedance spectroscopy (EIS) scales linearly with the logarithm of nitrite concentration. Due to its unique structure, the proposed nitrite sensor displays improved performance compared to our previous work, showing a linear range of 0.1 nM to 10 µM, a correlation coefficient of 0.9936, and an ultralow LOD of 17.3 pM. The results indicate that the modified electrodes possessed remarkable catalytic activity toward nitrite oxidation. Additionally, the ION-rGO nanocomposite-based sensor exhibited high sensitivity as well as good stability and reproducibility performance. The research findings demonstrate that the proposed sensor is a potential candidate for nitrite detection in real water sample analysis, which would be helpful in monitoring and protecting our global water resources.

Renewable energy-driven electrochemical ammonia synthesis using nitrates presents a promising pathway for producing ammonia while utilizing wastewater as a feedstock. This approach enables decentralized ammonia production and addresses environmental concerns related to nitrate pollution. If the broader goal is to use real wastewater as a feedstock, various anions and their influence on ammonia selectivity must be carefully studied. However, two significant challenges hinder its practical implementation: interference from common wastewater anions (sulfate, chloride, phosphate) and the lack of rapid, cost-effective ammonia monitoring methods suitable for process optimization. Here, an integrated solution combining fundamental studies of anion effects with an innovative paper-based detection platform is presented. This systematic investigation reveals how competing ions influence electrochemical ammonia selectivity, providing crucial insights for catalyst design. More importantly, a paper-based sensing protocol is developed that achieves sensitive ammonia quantification (10–500 µm range with 35 µm limit of detection) using merely 10 µL of sample. This field-deployable system eliminates the need for sophisticated instrumentation, delivering results three times faster than standard colorimetric assays while maintaining >90% accuracy. The sensor's robust performance enabled real-time monitoring of ammonia production from synthetic and real wastewater samples during electrochemical testing.

Lead halide perovskites have shown great promise for gas sensing applications due to their ability to detect and respond to gas exposures at room temperature. However, the toxicity of lead raises concerns, hindering their widespread use. To address this limitation, this study explores the potential of the lead (Pb)-free Cs₂AgBiBr₆ perovskite as a sensing element for room-temperature gas detection. This eco-friendly sensor, synthesized at room temperature without the use of harmful organic solvents, operates at low voltage (0.1 V) minimizing energy consumption. The perovskite material is synthesized using a precipitation method under ambient conditions, ensuring a cost-effective and environmentally friendly fabrication process. The influence of morphology on ozone (O₃) sensing performance is investigated, revealing that the microsheets exhibit the highest sensitivity. The sensor also demonstrates remarkable stability over time and under various humidity and temperature conditions, ensuring its reliable and robust performance in diverse environments. Notably, the sensor exhibits exceptional selectivity to O₃ over other gases, including nitric oxide (NO), hydrogen (H₂), methane (CH₄), and carbon dioxide (CO₂). This selectivity, along with the interaction between the gases and the perovskite surface, is confirmed through both experimental measurements and first-principles calculations. This technology holds immense potential for applications in air quality monitoring and industrial safety.

Taking advantage of the filmogenic properties of liquid crystal materials, bilayer heterojunction devices are built by combining them with a molecular semiconductor. Herein, the construction of a novel type of heterojunction sensor by employing bent-core liquid crystals (A1, A2, B1 and C-1C3) as a sublayer with lutetium bisphthalocyanine (LuPc₂) as a common top layer is achieved. Thanks to the modified drop casting method employed to deposit the sublayers, the resulting heterojunction devices exhibit a smooth surface, the morphology of the sublayer determining that of the top layer. All prepared devices are sensitive to ammonia, with a limit of detection below 10 ppm for C1, C2, and C3-based heterojunctions, even down to 2 ppm for C2-based devices, which is more than satisfactory for controlling ammonia levels in industrial working environments. Moreover, the C3-based device shows the shortest response time (t₉₀ = 30 s), which is suitable not only for air quality monitoring but also for applications like security alarm systems. All presented sensors operate at ambient temperature (20 °C) and humidity (45%).

Biomedical Sensing Technologies

Ammonia (NH₃) is a key biomarker in diagnostics, and sensors play a crucial role in its detection to improve medical diagnosis. In article 2400179, Annelot Nijkoops, Luisa Petti, and co-workers highlight recent advances in NH₃ sensing technologies and explores future research directions, including advancements in breath sensing, as well as in vitro and in vivo sensing.

This study presents the first investigation of a ReS₂-LaFeO₃ nanocomposite for the electrochemical detection of dopamine (DA). ReS₂-LaFeO₃ nanocomposites (5%, 10%, and 20% ReS₂ by weight) are synthesized hydrothermally on porous LaFeO₃ nanofibers prepared via electrospinning and annealing. The resulting materials are thoroughly characterized using spectroscopic and microscopic techniques. Electrochemical DA detection (0.02 µm – 1 mm) is performed using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CA). The 10 wt.% ReS₂-LaFeO₃ nanocomposite demonstrates exceptional performance, achieving a high sensitivity of 0.191 µA µM⁻¹ cm⁻². In comparison, LaFeO₃, 5 wt.% ReS₂-LaFeO₃, 20 wt.% ReS₂-LaFeO₃, and pristine ReS₂ exhibit limits of detection (LODs) of 281, 357,187, and 120 µm, with corresponding sensitivities of 0.191, 0.156, 0.181, 0.183 µA µM⁻¹ cm⁻², respectively. The representative 10 wt.% ReS₂-LaFeO₃ nanocomposite exhibits good selectivity and detection performance, as confirmed by tests with 1 mm concentrations of common analytes in biological relevant chemicals such as uric acid (UA), sodium chloride (NaCl), hydrogen peroxide (H₂O₂), and ascorbic acid (AA). Furthermore, it shows varying response toward other neurotransmitters like epinephrine (EP) ad norepinephrine (NEP). The results of this investigation show that ReS₂ decoration on LaFeO₃ enhances the nanocomposite's physical, chemical, and electrical properties, leading to improved charge separation and reliable DA sensing in complex biological samples.