Advanced Sensor Research最新文献

Corroles, a family of contracted porphyrinoids, exhibit broad chemical interactions, undergo straightforward synthetic preparation and functionalization, and enable versatile thin film deposition. These attributes render them promising candidates for use in chemical sensors. Nevertheless, the inherently limited conductivity of corrole solid films constrains their application in mass and optical sensors. Despite this impediment, there is a great interest in matching the sensitive properties of the corrole with the features of facile miniaturization and integration into low-cost electronic circuits. This work explores the possibility of directly and simply depositing conductometric polymeric films of [5,10,15-(4-aminophenyl)corrolato] copper onto interdigitated electrodes. Remarkably, the electropolymerization protocol allows the selection of the semiconductive nature (p- or n-type) of these films, yielding two distinct sensor types: the former exhibiting high sensitivity and selectivity toward nitrogen monoxide (NO) with a slight influence of relative humidity and the other manifesting a broad spectrum of sensitivities. This breakthrough lays the foundation for developing miniaturized conductometric gas detectors, nonlinear conductometric sensing elements, and electronic nose platforms based on polycorroles.

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.

Using the flexibility and diversity of material and structure designs possible with 3D printing fiber technology, an all-solid photonic crystal fiber (PCF) is fabricated using borate (B₂O₃) doping. The geometry, material, and optical properties of this 3D printed PCF are characterized and analyzed using optical microscopy, scanning electron microscopy (SEM), fiber index profilometry, and Fourier transform infrared (FTIR) microscopy. Analysis demonstrates that B₂O₃ doped in fabricated PCF has experienced evaporation leading to mass loss during drawing. In addition, there is no observable difference between the structure of substrate silica (SiO₂) and the SiO₂ nanoparticles. However, microdomain differences may explain enhanced reflectance. Furthermore, a Mach–Zehnder interferometer (MZI) sensor is constructed with this 3D printed solid PCF and applied to temperature, refractive index, tensile force, and bending sensing. The specially designed 3D printed PCF has maximum temperature sensitivity up to Δλ/ΔT ≈0.075 nm °C⁻¹. When immersed in 76.34 wt.% glycerol-water solution, the sensitivity can be further improved. These results demonstrate that 3D printing fiber technology enables the custom fabrication of highly sensitive optical fiber sensors, increasing opportunities for the development of diverse and flexible sensors and devices for future internet-of-things (IoT) applications.

The development and application of Electrochemical Quartz Crystal Microbalance (EQCM) sensing to study metal electroplating, especially for energy storage purposes, are reviewed. The roles of EQCM in describing electrode/electrolyte interface dynamics, such as the electric double-layer build-up, ionic/molecular adsorption, metal nucleation, and growth, are addressed. Modeling of the QCM sensor is introduced and its importance is emphasized. Challenges of metal electrode use, including side reactions and dendrite formation, along with their mitigation strategies are reviewed. Numerous factors affecting the electroplating processes, such as electrolyte composition, additives, temperature, and current density, and their influence on the electroplated metals’ mass, structural, and mechanical characteristics are discussed. Looking forward, the need for deeper fundamental understanding and advancing simulations of the QCM signal response as a result of electroplating metal nanostructures is stressed. Further development and integration of innovative EQCM-strategies will provide unique future means to fundamentally understand and optimize metal electroplating for energy storage and application alike.

Smart hydrogel sensors, functioning as implantable devices, play a vital role in health monitoring and early warning, overcoming the limitations of conventional clinical methods to achieve direct, continuous, and precise monitoring. Widely employed across various biomedical fields, these sensors offer unique advantages for early health monitoring, ensuring direct, continuous, and highly accurate monitoring. In addition to detecting biomolecules, smart hydrogel sensors, with their flexibility and biocompatibility, monitor disease-specific markers, offer insights into disease progression, and contribute to the early identification of diseases. This article provides a comprehensive review of the types of hydrogel sensors employed in human health monitoring. The study discusses recent advancements in smart hydrogel sensor research, aiming to offer promising methods for human health monitoring. Finally, the paper outlines prospective research directions for hydrogel sensors in the field of human health monitoring. While further research and clinical validation are essential, hydrogel sensors are poised to play a pivotal role in clinical applications, furnishing people with accurate and continuous health monitoring.

A serous effusion is a buildup of extra fluid in the serous cavities including pleural, peritoneal, and pericardial cavities. It is important to distinguish benign reactive effusions from effusions caused by malignant proliferation in cytopathology since different diagnoses can lead to completely different disease staging and therapeutic choices. The conventional cytopathology procedure has the disadvantages of low throughput and low objectivity. To enhance the efficiency and accuracy of malignant serous effusion diagnosis, in this paper, an imaging flow cytometry, called optofluidic time-stretch microscopy is first employed, to image the cells in the serous effusion at an event rate of 100 000 events per second and with a spatial resolution better than 1 µm. The acquired cellular images are then analyzed using a convolutional neural network, by which the malignant cells are accurately detected. The performance of the method is validated with 18 clinical samples, including 14 malignant and 4 benign ones. The results show that the method can detect malignant cells at an accuracy of 90.53%. The high throughput, high accuracy, and high convenience of the method make it a potential solution for malignant serous effusion diagnosis in various scenarios.

This review delves into the significant advancements in microfluidic technology since 2017, highlighting its critical role in shrinking device sizes and integrating advanced surface functionalization techniques. It showcases how microfluidics, an interdisciplinary field, has revolutionized fluid manipulation on a microscale, enabling the creation of cost-effective, portable devices for on-the-spot analyses, like heavy metal ion detection. From its early days rooted in ancient observations to cutting-edge uses of materials like silicon, glass, polydimethylsiloxane (PDMS), and paper, this review charts microfluidics’ dynamic evolution. It emphasizes the transformative impact of surface functionalization methods, including silanization and plasma treatments, in enhancing device materials' performance. Moreover, this review anticipates the exciting convergence of microfluidics with emerging technologies like droplet microfluidics and three-dimensional (3D) printing, alongside nanotechnology, forecasting a future of sophisticated analytical tools, point-of-care diagnostics, and improved detection systems. It acknowledges the hurdles in scaling production and achieving universal reliability and standardization. This review highlights the transformative impact of microfluidic technology on diagnostics and environmental surveillance, emphasizing its utility in deploying compact sensors for comprehensive and concurrent evaluations of water quality.

Flexible Modulus Sensor

In article 2300148, Hengchang Bi, Xing Wu, and co-workers report a modulus sensing system with a characteristic of high linearity detection, which consists of a pressure sensor and a vibrator. It is able to quickly identify the physiological state of human body based on the modulus change of the detected tissues, exhibiting great potential in the health monitoring, such as the concept eye mask for migraine monitoring.