Sensing and Bio-Sensing Research最新文献

Radiometers and Wearable biosensors, as vital parts of the realm of quantum medicine, are becoming popular for their ability to continuously and immediately provide physiological data through single-cell spectroscopy, brain imaging, and noninvasive monitoring of biochemical markers in various neuroimaging and biofluids such as sweat, tears, and interstitial fluid. Various biosensing, microfluidic sampling, and transport technologies have been combined, made smaller, and incorporated with flexible materials to improve ease of use and comfort. Enhancing the understanding of the connections between noninvasive biofluids and blood analyte levels is crucial for improving the reliability of wearable biosensors. This review discusses the noninvasive monitoring of biomarkers such as hormones and metabolites utilizing electrochemical and optical biosensors, single-cell spectroscopy, and brain imaging. Increasing the number of biomarkers for monitoring will need further on-body bio affinity testing and various sensing devices. Large-scale validation studies with many participants are necessary to use wearable biosensors in therapeutic settings. Wearable biosensor technology's ability to quickly and accurately detect real-time physiological data in therapy might significantly impact our daily routines

This work investigates the electrical field distribution in polymeric electrodes, materials composed of polymers and nanoparticles that leverage the physicochemical interactions between constituents to modify mechanical and electrical properties. Polymeric matrices often incorporate carbon nanoparticles to impart specific conductive properties while simultaneously enhancing mechanical stability through a protective polymer layer. The morphology, dielectric properties, and geometric configuration of these materials influence the electric field distribution, which is critical to their functionality. Utilizing finite element modeling, this study not yet explored aims to predict these effects and guide the design of material compositions and structural geometries to optimize functionalities like catalytic activity, adhesion enhancement, and interface energy reduction. Simulations were conducted using COMSOL 6.0 across eight similar geometric configurations, assessing polarization, and electric potential distribution. Results underscore the importance of surface polarization in controlling roughness and optimizing biosensor performance for liquid samples. Notably, controlled surface roughness induces asymmetric electric field distortions at biosensor edges, influencing dipole moments in polarizable nanoparticles. Each tested geometry demonstrated unique characteristics pertinent to its application in 3D-printed biosensors, influenced by surface roughness and wettability. Additionally, modifications in the electrical double layer due to controlled roughness alter charge distributions at the electrode-electrolyte interface, affecting electric field configurations.

Bisphenol S (BPS) is a common, persistent, and mobile chemical found in everyday products such as thermal paper. BPS can easily enter the body by migrating from the paper to the fingers, disrupting the endocrine system by mimicking the oestrogen hormone, thus negatively influencing human health. Assessing BPS levels in daily life is of great importance. This study introduces a rapid and reliable approach for detecting BPS in thermal paper and tap water by developing an electrochemical analytical method. This method allows for in-situ, real-time measurements. We present a simple, low-cost electrochemical sensor for detecting BPS using screen-printed electrodes based on carbon (SPEC) and single-wall carbon-nanotube (SPE-SWCNT) working electrodes. BPS was detected over a wide linear range from 1 to 400 μM. The detection limits were 0.73 μM and 0.87 μM for the SPE-C and SPE-SWCNT electrodes, respectively. Good repeatability was observed for both sensors when using one electrode 16 times, which demonstrates its potential for real-time environmental monitoring. Additionally, traditional chromatographic methods, high-performance liquid chromatography with a diode-array detector (HPLC-DAD), and liquid chromatography-mass spectrometry triple quadrupole (LCMS), were incorporated to enhance analytical capabilities. HPLC-DAD achieved a detection limit of 3 nM after solid-phase extraction preconcentration, while LCMS triple quadrupole demonstrated a detection limit of 10 pM without preconcentration. Electrochemical screen-printed electrodes can be employed for on-site analysis and health-risk assessments in everyday settings, such as shops. However, for detecting very low concentrations where time is not a constraint, LCMS quadrupole remains the preferred technique.

Given the increasing demands for quality assurance in the food industry, a significant challenge emerges in the form of expensive integration of food sensors into packaging. This integration is crucial for strengthening food safety measures and ensuring the impeccable quality of food products. Official laboratory food safety testing heavily relies on expensive and bulky equipment. This article presents a new chemical sensing platform and a comparative study of in-house built novel designs for a robust multimode chemical sensor head probed by highly sensitive light-sheet skew rays for addressing cost and footprint issues. The sensing mechanism is the interaction between evanescent field mediated by refined skew rays propagating through a structured coreless multimode fiber and external chemicals, resulting in probe light absorption. The sensitivity is enhanced by the controlled excitation of skew rays using a light sheet and four specially engineered coreless multimode fiber structure, including uniform, tapered, microstub and microbubble designs. The sensitivity was demonstrated to be as high as 0.046 (dB/cm) / dB_{(1 ng/ml)} and the limit of detection as low as 1.028 ng/ml for the microbubble structure. The results of our research pave the groundwork for a new range of chemical sensors suitable for food safety monitoring.

Here, we report the selective detection of biotinylated interleukin-6 receptor (IL-6R) protein using both chemical vapor deposition (CVD) and epitaxial graphene (EG) based electrochemical sensors and their reusability. Detection was based on the principle of avidin-biotin technology, which was widely used in different types of sensor technology. Following the characterization of graphene, the CVD and EG on SiC were fabricated with gold nanoparticles using our recently developed technique. The CVD graphene-based device was made by transferring the CVD graphene onto an interdigitated array electrode (IDA). In contrast, the EG-based device was made by photolithography by fabricating interdigital electrodes on EG on SiC. The detection of IL-6R was monitored by real-time two-terminal current measurements at fixed voltages, while the IL-6R protein was injected into avidin-immobilized graphene-based devices. Drops of the current (Ids) upon injection of as low as 50 pg/ml of IL-6R solution confirm the detection of IL-6R with ultra-high sensitivity. The specificity of the device was confirmed by a chicken egg white solution in PBS, which contains a variety of biomolecules. The EG on a SiC-based device can also be used to detect biomolecules with high sensitivity. The EG on the SiC-based device was found to be reusable after the physical cleaning procedure. The present study is expected to be exploited in the development of reusable ultra-sensitive point-of-care biosensors.

In this work, a novel electrochemical thyroglobulin (Tg) biosensor was fabricated based on modification of a glassy carbon electrode with chitin-ionic liquid (Ch-IL) and gold nanoparticles (Au NPs). Surface of the Au NPs/Ch-IL/GCE was investigated and optimized by the image processing method. Drop-casting of the Ch-IL was performed onto the surface of Au NPs/Ch-IL/GCE to fabricate Ch-IL/Au NPs/Ch-IL/GCE. Then, sortilin (ST) was immobilized onto its surface by the use of glutaraldehyde. Biosensing of Tg in the range of Tg in the range of 0.1 to 8.5 fM was based on its interaction with the ST and change in hydrodynamic differential pulse voltammetric (DPV) response of the biosensor. The second-order calibration methods by U-PLS/RBL, N-PLS/RBL, MCR-ALS and PARAFAC2 were used to determination of Tg in the presence of thyroxine and triiodothyronine as uncalibrated interference, and our results confirmed the best performance was observed for exploiting second-order advantage by PARAFAC2 (sensitivity: 2.8 μA/fM, selectivity: 0.49, inverse of analytical sensitivity: 0.11 fM⁻¹, limit of detection: 0.01fM) which was used to determination of Tg in human serum samples the presence of triiodothyronine and thyroxine as uncalibrated interference with the aim of detection of thyroid cancer treatment success. The ST/Ch-IL/Au NPs/Ch-IL/GCE assisted by PARAFAC2 was an excellent electronic device for medical diagnostic purposes.

Protein phosphorylation in sweat metabolites plays a key role in nerve activity, muscle contraction, and other activities, and abnormal protein phosphorylation may lead to diseases such as neurodegenerative disorders. Real-time non-invasive monitoring of changes in phosphorylated protein levels in sweat facilitates the development of prevention of human degenerative neurological diseases. Here, an electrochemical sensor for the detection of trace phosphoproteins in sweat was constructed by exploiting the selective enrichment ability of the TiZr dual active center in the TiO₂ NPs@UiO-66 structure for phosphoproteins. The common phosphoprotein α-Casein was selected as a demonstration sample to show the functionality of the designed sensing platform. The sensor exhibited excellent selectivity, repeatability, reproducibility and stability with a detection limit as low as 0.659 μmol/L and a detection range of 1–10 μmol/L. In addition, the low biotoxicity of the prepared materials was verified by biological experiments on SD rats and volunteers, which can meet the needs of skin-friendly biosensors. The detection of phosphoproteins in human sweat at rest and during exercise verified the performance for practical applications. This work realizes the goal of non-invasive and continuous detection of phosphoproteins in sweat in wearable devices.

This work considers cerebral stress-struck adults to assess their ‘acumen’ with four quantified anthropometric indices like cell membrane capacitance (CM), total body impedance (TBI), total body fat (TBF), and total body water (TBW). Primarily, a bio-impedance model of the epithelial tissue structure of human body has been presented and anatomized considering mental stress driven hormonal changes happen inside human body to propose several preambles. Secondly, an intelligence quotient (IQ) test designed to create ‘racing’ thoughts has been conducted right before measuring indices using bioelectrical impedance spectroscopy (BIS) method. Finally, juxtaposed investigations to vindicate the correlation between bio-impedance model-implied preambles and the variance of the four quantified indices were made by comparing them to the IQ test outcomes. This article reports, an effectively innervated nervous system having homeostasis endocrine human anatomy with CM, TBI, TBF, and TBW, in the range of 1.0–2.1 nF, 470–550 Ω, 7.9–20%, and 56.8–80%, respectively for the subjects whose acumen is classified as “Class-A", while “Class-B" subjects are also presented with other distinct quantified indices. The outcomes of this work are expected to be a paradigm in the digital judgment of adults' psychological engagement to any tasks.

In this manuscript, a sensor is devised employing photonic crystal fiber with localized surface plasmon resonance (PCF-LSPR), emphasizing the manipulation of refractive index (RI) through magnetic fluid (MF). The sensor's air holes adopt a hexagonal arrangement, forming a butterfly core design, and the transmission channels for the effective confinement of optical field energy relies significantly on the regions surrounding the central air hole in both directions. MF serves as the sensing medium, and the top and bottom polished surfaces are coated with gold and titanium dioxide. The sensor undergoes analysis using the finite element method, scrutinizing its model characteristics, structural parameters, and sensing performance. The results indicate a wavelength sensitivity of up to 45,600 nm/RIU and a maximum figure of merit (FOM) of 434 ${\mathrm{RIU}}^{-1}$. Within the range of magnetic field 30–150 Oe, the highest magnetic field sensitivity records 3350 pm/Oe. Over the temperature range of 27.4–114 °C, the temperature sensitivity measures only 310 pm/°C. A maximum sensor resolution of $2.19\times {10}^{-6}$ RIU is achieved for x$-$pol. The linear relationship between the resonant wavelength and the magnetic field yields $R^2=0.9945$, for degree (2) for x$-$pol. The proposed sensor exhibits notable advantages, including a structure which is very stable, high sensitivity, ease of integration, and resilience to electromagnetic interference. Additionally, it excels in detecting weak magnetic fields. Its potential applications span from industrial production, military technology, to medical equipment.

Immunoassays with magnetic nanoparticles (MNPs) as markers are a promising approach for the fast and sensitive virus detection. Upon binding of antibody-functionalized MNP on virus proteins, the hydrodynamic diameter increases and a change in the Brownian relaxation time can be measured. In this study, we detect the whole SARS-CoV-2 by mimicking it with streptavidin-coated polystyrene beads with biotinylated spike proteins. Changes of the MNP dynamics are measured by alternating current susceptometry and magnetic particle spectroscopy. Due to the multiple binding sites of MNP and virus, crosslinking enlarges the change of the hydrodynamic diameter. In order to improve the sensitivity and the limit of detection of the assay, the ratio of the virus to the MNP amount R_MV/MNP is investigated in detail. High R_MV/MNP ratios lead to a saturation of the MNPs with viruses, so that the cluster size and therefore the sensitivity decrease again. Additionally, it is found that the smallest virus concentrations can be detected for small MNP concentrations. It is also shown that the R_MV/MNP range that can be used for an unambiguous detection of viruses depends on the virus/MNP concentration; it shifts with increasing MNP concentration to smaller R_MV/MNP values. For very small virus concentrations, an increase of the Brownian relaxation time is detected implying a decrease of the hydrodynamic diameter. Furthermore, the optimal antibody concentration for MNP functionalization was determined. It is also found that a washing process with a centrifuge improves the sensitivity by reliably removing unbound antibodies and eliminating small MNPs with improper functionalization.