Sensing and Bio-Sensing Research最新文献

We present a therapeutic drug monitoring (TDM) feasibility study using a label-free surface-enhanced Raman spectroscopy (SERS)-based assay for quantifying methotrexate (MTX) from samples collected from children with acute lymphoblastic leukemia undergoing high-dose MTX therapy. We show that, when combined with an appropriate sample preparation (solid phase extraction) and multivariate data analysis (partial least squares regression), the SERS assay demonstrated a good correlation with a reference chromatographic method (r = 0.889, p < 0.005). We also found that the SERS-based approach underestimated MTX concentration, with a 10% bias calculated, but both methods showed similar variability (RSD of 8.4% for HPLC and 11.6% for SERS). The presented results are strong evidence that SERS can be used for TDM of MTX, and this work brings us one step closer to implementing a SERS-based assay in clinics.

The analysis of food and drugs as well as the monitoring of chemical processes and bioreactors by high-performance liquid chromatography and ion chromatography requires universal, cost-effective, and sensitive detectors. Therefore, this work presents a split-ring resonator that detects changes in the electrical and dielectric properties of the eluate from liquid chromatography or ion chromatography by monitoring the amplitude of the transmitted signal using an envelope detector. The used split-ring resonator consists of a simple printed circuit board featuring two microstrip lines. One is formed to a ring with interdigital split electrodes. The interdigital split electrodes forming the sensitive area significantly enhance the sensitivity to changes in relative permittivity, dielectric losses and electrical conductivity of the eluate In addition, the split-ring resonator is a small, inexpensive and easy-to-use detector that uses several dielectric parameters simultaneously for the measurement. Furthermore, the split-ring resonator measures these parameters at a significantly lower frequency than optical detectors and therefore measures different changes in frequency-dependent permittivity. For demonstrating feasibility of a split-ring resonator as a detector for high-performance liquid chromatography and ion chromatography, various anion and cation standards, basic and acidic amino acids, sugars, as well as sugar alcohols were separated and detected. A conductivity detector for ion chromatography and a refractive index detector for high-performance liquid chromatography were used as reference detectors.

The method by which a photonic crystal is manufactured fiber is detailed throughout the subsequent undertaking, containing a hexahedron core and hazardous dietary additives using a hexagonal cladding. Saccharine, sorbitol, and butyl acetate are used as analytes for sensing purposes. The sensor contains five tiers of circular ventilation holes within the hexagonal framework, as well as two tiers of hexahedron circles in the central area. FEM (Finite Element Method) is implemented in the sensor design of COMSOL software version 4.2. We noticed the response of the PCF sensor to the specific substances. We examined key optical metrics encompassing specifications including V-parameter, Relational sensitivity, effective refractive index, and power fraction to assess the suitability of the sensor for precisely and effectively detecting various food additives. The revised model attains sensitivity values of 90.10%, 91.30%, and 86.60%, respectively, at a frequency of 1 THz, the identification of saccharine (1.550 in the index of refraction), sorbitol (1.375 in the index of refraction), and butyl acetate (1.394 in the index of refraction) is performed. Furthermore, the compositions of saccharine (1.550 in the index of refraction), sorbitol (1.375 in the index of refraction), and butyl acetate (1.394 in the index of refraction) demonstrate losses from confinement of 6.15 × 10⁻⁸ dB/m, 7.25 × 10⁻⁸ dB/m, and 6.35 × 10⁻⁸ dB/m, which are comparatively minimal, and 0.0235 cm⁻¹ is an insignificant effective material loss. These structures are studied at the terahertz frequency spectrum. Owing to its superior wave-guiding properties, this proposed sensor can be used for polarization-preserving terahertz wave applications and detecting dangerous food additives. Besides, because of simple fabrication, high sensitivity, and low confinement loss, we strongly believe this optimized geometrical structure will contribute to real-life applications that lead to safer food and support a circular economy in developing countries.

The biochemical oxygen demand (BOD) is critical for assessing water quality, linking the quantity of biodegradable organic carbon with pollution levels. Electrochemical biosensors have shown great improvements over traditional BOD measurement methods by offering the advantages of simplicity, rapid response, high sensitivity, and real-time monitoring. In this review, we discuss different types of BOD electrochemical biosensors, including oxygen electrode-, microbial fuel cell (MFC)-, and microbial electrolysis cell (MEC)-type sensors, focusing on recent advances in microbial community composition, electrode materials, and optimization approaches. Moreover, current challenges in developing effective electrochemical biosensors for BOD detection are presented to meet diverse sample needs.

Nuts are a well-known cause of food allergy and, once this has been diagnosed, due to the likelihood of cross-sensitization to multiple tree nut allergens, their strict avoidance from the diet is advisable. In this context, we present electrochemical bioplatforms to detect traces of hazelnut and walnut in processed foods through the determination of their respective allergenic proteins Cor a 9 and Jug r 1 in a fast and sensitive assay. First, the evaluation of the single determination of both proteins was performed by building sandwich immunoconjugates on the surface of magnetic microbeads relying on specific antibodies unmodified or conjugated to horseradish peroxidase. Amperometric transduction was made upon trapping the magnetic bioconjugates on the surface of disposable carbon electrodes, using the hydroquinone/hydrogen peroxide system. The great analytical performance achieved with the individual platforms (detection limits of 0.12 and 0.56 ng mL⁻¹ for Jug r 1 and Cor a 9, respectively), led us to the individual and dual quantification of both proteins in raw dough and baked cookies incurred with ground nuts. The developed method allowed detecting baked cookies incurred with 0.0025% ground walnut and 0.00002% ground hazelnut with results comparable to those provided by ELISA techniques. The feasibility of performing the dual determination of both allergens in a single run was demonstrated.

In this study, a simple, fast and sensitive voltammetric detection using boron-doped diamond (BDD) electrode was proposed for simultaneous quantification of benzene (BZ), naphthalene (NF) and anthracene (AC) from priority organic pollutants class in real tap water. The electrochemical behaviors of individual and simultaneous BZ, NF and AC studied by cyclic voltammetry (CV) on BDD electrode showed a large separation between their oxidation potential, which allowed the development of simple simultaneous detection method. Differential-pulse voltammetry (DPV) technique operated at step potential of 5 mV and modulation amplitude of 200 mV enabled to reach the lowest limits of detection of 0.40 μM for BZ, 0.04 μM for NF and 0.70 nM for AC, which is appropriate for water quality control related to their environmental quality standards. No significant influence of chloride ions was found and the method was validated in real tap water and surface water spiked with known concentrations of BZ, NF and AC, which proved the practical utility of the method for water quality control.

A biochip assay provides high-throughput and multiplexed analysis of biological samples, chemicals, and natural products. Pruritus is itchiness due to several causes, such as allergy, dry skin, pregnancy, liver disease, kidney disease, and thyroid disease. Treatment of pruritus is associated with reduced immunoglobulin (IgE) and FcεRI levels in sera. Treatment of pruritus include corticosteroid creams or ointment. However, they have side effects, so we need a safer treatment using natural products. Here, we developed an assay using protein chip technology to identify natural products with antipruritic activity that inhibit IgE-FcεRI binding. Of the 28 tested natural product extracts, Corni Fructus extract inhibited human IgE-FcεRI binding and also showed anti-histamine effects in MC/9 mast cells. These results suggest that this protein biochip assay system can be used to identify promising natural product extracts for the treatment of pruritus.

Nanogap nanowires have gained attention for their potential applications in biosensing due to their unique physical properties, such as high surface-to-volume ratios and enhanced sensitivity. These nanowires can be used as electrodes in electrochemical biosensors, improving the sensitivity and selectivity of these devices. They can also be integrated into sensor platforms using mature nano-fabrication procedures. These advancements offer great potential for developing highly sensitive and accurate biosensors for various applications, including biomedical diagnostics, environmental monitoring, and food safety. Nanogap nanowires have revolutionized the field by providing enhanced sensitivity and accuracy in detecting biological molecules. They have also been used in the fabrication of segmented nanowires for chemical sensing, allowing for more precise and targeted detection of specific analytes. Nanogap nanowires have shown promise in protein biomarker analysis, enabling ultra-sensitive detection of protein biomarkers at low levels. This review provides an overview of recent advancements in Nanogap Nanowires and their applications in biosensing.

Utilizing LC resonant metamaterials (MM) for terahertz (THz) impedance spectroscopy has opened new avenues for detection of biomolecules and nanoparticles. A recent revelation highlights the pivotal role of coupling between MM resonance and Fabry-Pérot (FP) oscillations of the substrate. This interaction significantly influences the observed spectral shift ($\mathrm{\Delta F}$), thereby enhancing the overall sensitivity. In this work, we utilize the FP-MM optical decoupling physics for sensitivity enhancement to detect bio-particles at extremely low concentrations, thereby overcoming the particle detection limit. After implementing these innovations, we discovered that this technology can be leveraged to detect and screen patients infected with the omicron variant of SARS-CoV-2 and other lung related diseases using exhaled breath from patients. Upon achieving excellent agreement between simulations and experimental spectroscopic data, we have successfully detected and screened multiple respiratory-related diseases from the exhaled breath collected on the metasurface in a breathalyzer configuration. We obtained significant $\mathrm{\Delta F}$ even with ultra-low concentrations of bio-particles and demarcated the ranges of $\mathrm{\Delta F}$ for different lung diseases that do no overlap and are not constrained by any limit of detection. This work reveals new prospects for diagnosis and screening of multiple respiratory-related diseases with a single and prompt breath test.

In this paper, an innovative device with gas remote-sensing capability is proposed, which is based on the interaction between magnetic nanoparticles and gases associated with exhaled breath biomarkers that can have a metabolic origin. Magnetite (Fe₃O₄) nanoparticles of around 30 nm have been used. The gas molecules adsorbed on surface modulate the magnetization of the nanoparticles and magnetostatic surface spin waves (MSSW) propagated on an yttrium iron garnet (YIG) thin film are used to detect this modulation by the induced frequency shift. The optimization of the remote gas sensor has been carried out through simulations of a magnetic model. Simulations show the feasibility of developing a high-performance remote sensor by encapsulating the nanostructures in a polytetrafluoroethylene (PTFE) tube and detecting part per million changes in their magnetization. The results show the possibility of developing new, inexpensive, reusable, contactless magnetic gas sensors employing spin waves as transductor. The developed sensor shows a high sensitivity and selectivity to concentrations as low as 50 ppm of different breath biomarkers.