Advanced Sensor Research最新文献

Reliable detection of hydrogen (H₂) leakage at low temperatures (e.g., < 273 K) is highly desired in those critical environments that may cause failure in detection, which needs further development. Herein, H₂ sensing that can work at ≈190–388 K temperature range has been developed by integrating palladium and zinc nanowires enwrapped with nanosheets (PdZn NWs) as the sensing materials, which have been prepared via combined anodic aluminum oxide (AAO) template-confined electrodeposition and surface engineering. Typically, as-synthesized PdZn NWs with a diameter of ≈50 nm present rough surfaces, along which abundant pores and fractures have been observed. Beneficially, the PdZn NWs show a lower critical temperature (≈190 K) of the “reverse sensing behavior” than that of pure Pd NWs (287 K), indicating the PdZn NWs are able to work at ≈190–388 K temperature range. Theoretically, such stable H₂ sensing can be attributed to the rough surfaces and chemical composition of PdZn NWs, which facilitates H atoms diffusion and accommodates the expansion of PdHx intermediates. The surface engineering of PdZn NWs may contribute to stable H₂ sensing at low temperatures, which can be applied to other gas-sensing materials working at low temperatures.

To develop a field applicable hazardous molecular detection system, highly sensitive and multiplex detection capability is required for practical utilization. Here, a paper-based 3D spiky needle-clustered gold grown on silver (Ag@Au) plasmonic nanoarchitecture (3D-SNCP) is fabricated through whole solution process. The developed substrate is investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) to find out morphological development mechanism. Also, finite-domain time difference (FDTD) simulation is conducted for the observation of electromagnetic field (E-field) distribution. After surface-enhanced Raman scattering (SERS) characterization, the 3D-SNCP is utilized for ultra-sensitive and multiplex hazardous molecular detection, such as bipyridine pesticides including paraquat (PQ), diquat (DQ), and difenzoquat (DIF). Then, each of pesticide molecular Raman signals are trained by a machine learning technique of multinomial logistic regression (MLR), followed by multiplex classificationf of blank, PQ, DQ, DIF, and four mixture types of each pesticide, spiked in real agricultural matrix. The developed 3D-SNCP substrate combined with the machine learning method successfully verifies the multiple pesticides and it is expected to be applied for various hazardous molecular detection in much complicated matrix environments.

Developing progressive photoelectrochemical (PEC) techniques holds great potential for advancing analytical sensitivity in clinical. However, the low transport and separation of charge carrier efficiency and deficient active sites block efficient and durable PEC analytical performance features. And herein a piezo-assisted PEC sensing platform for glutathione (GSH) detection are successfully prepared based on S vacancies rich CdS (S_v-CdS) nanowires. The collaboration of piezoelectric polarization and S vacancies engineering contributed to the boosted PEC performance by accelerating the spatial separation of photogenerated charges and providing abundant active sites. Moreover, the charge transfer efficiency further promoted with the introduction of GSH acted a hole scavenge that effectively suppresses the electron-hole recombination, giving rise to an amplified photocurrent. As a demonstration, the proposed method presents an outstanding analytical performance toward GSH. Consequently, this work provides an inspirable and convenient route for designing high-efficiency photoelectrode in PEC sensing in virtue of judicious structural, and defect engineering, and the exploring of an external-field-coupling-enhanced PEC platform.

Magneto-plasmonic particles, comprising gold and iron oxide, exhibit substantial potential for biosensing applications due to their distinct properties. Gold nanoparticles (AuNPs) provide plasmonic features, while iron oxide composites, responsive to an external magnetic field, significantly reduce detection time compared to passive diffusion. This study explores core@satellite magneto-plasmonic particles (CSMPs), featuring magnetic nanoparticle clusters and numerous satellite-like AuNPs, to amplify the optical response on a nanostructured gold surface. Using a sandwich scheme, target analytes are detected as hybrid nanoparticles bind to the pre-immobilized target on the AuNPs surface, inducing changes in the immunosensor's extinction spectrum. Application of an external magnetic field notably enhances biosensor response and sensitivity, reducing assay time from hours to minutes. Leveraging the properties of CSMPs, the immunosensor detects specific immune protein at low concentrations within minutes. CSMPs hold considerable promise for precise and sensitive analyte detection, offering potential applications in rapid testing and mass screening.

3D-Printable Sensors

This study investigates the development of 3D printable thermoplastic polyurethane filaments incorporating multi-walled carbon nanotubes (MWCNT) for enhanced strain-sensing capabilities. Piezoresistive structures are fabricated and tested to demonstrate the potential applicability of the custom filaments. More details can be found in article number 2300198 by Behrad Koohbor and co-workers.

Lipid Droplet Imaging

In article 2300178, Yuning Hong and co-workers present a newly developed imaging agent for cellular lipid droplets. This high-performance fluorescent dye is capable to quantify lipid droplet dynamics in live cells and reveals larger but fewer lipid droplets in fibroblasts from ME/CFS patients compared to the healthy controls, suggesting their potential application in disease study and diagnosis.

In diagnostic tools, rapid in vitro tests such as COVID-19 antigen or pregnancy tests are gaining significance for identifying various pathologies or health conditions. This shift contributes to a change in the way diagnostic efforts are carried out, emphasizing decentralized approaches that offer valuable services within communities, yielding long-term advantages for the healthcare system. Considering the substantial quantity of these tests manufactured and used annually, a straightforward manufacturing process is proposed for highly sensitive carbon electrodes designed for antibody-type biomarker sensors. This process, utilizing pad printing – an additive, low-temperature, and cost-effective method, coupled with plasma activation – has proven the electrodes capability to measure interferon gamma protein, a tuberculosis biomarker. Using electrochemical impedance spectroscopy, the electrodes display high sensitivity and are capable of measuring concentrations from 10 to 1000 pg mL⁻¹ in undiluted serum within an hour. The sensor, utilizing solely a monolayer of antibodies, achieves a performance equivalent to that of a commercial standard sandwich ELISA tested in this study.

Foreign body response is the main reason for the limited lifetime of implantable glucose biosensors. A new measurement strategy exerting minimal disturbance from the equilibrium glucose concentration in the sensor compartment has been proposed to mitigate its adverse effects on the sensor signal. Here, a new measurement strategy using automatically fabricated and robust pencil-lead-based glucose biosensors is implemented. The sensor response depends on critical parameters such as redox-polymer film thickness, film uniformity, rigidity, polymer composition, and the ratio between the enzyme and the polymer. These parameters are controlled by introducing a short-chain redox polymer, a low crosslinker amount, a short-chain electrografting agent and linker, pulse electrografting, and an automated fabrication procedure.