Sensing and Bio-Sensing Research最新文献

Due to the global pandemic of influenza and related respiratory diseases, rapid and accurate detection is in high demand to control virus spread and facilitate early treatment. However, most current molecular detection methods either require long turnaround times, suffer from low sensitivity and/or can only detect single pathogens. To overcome these challenges, we constructed a novel colorimetric gold nanoparticle (AuNPs) biosensor containing functionalized probes to detect multiple targets simultaneously. Utilizing the salt aging method, AuNPs were functionalized by the designed oligonucleotides to fabricate biosensors. This biosensor can show visible color change within 20 min, and could minimally detect the target influenza viruses at 10 nM. This detection technique presents high sensitivity in a short time, meanwhile identifying two different influenza viruses simultaneously. It opens a window to a multiplex-in-one strategy for a clinical viral diagnostic.

Chemical submission, a nefarious tactic increasingly employed in criminal activities, has spurred urgent calls for innovative countermeasures. GHB, often dubbed “liquid ecstasy,” stands out as a favoured agent for its surreptitious nature and seamless solubility in water and alcoholic beverages. Addressing this menace head-on, a groundbreaking study delves into the development of advanced chemosensors, leveraging 2-aminonaphtoxazole- and benzoxazole-based compounds adorned with fluorescein, to construct a cellulose paper-based detection system. This ingenious setup not only detects GHB in water but extends its vigilance to real alcoholic and non-alcoholic beverages, illuminating a pathway to thwart potential assailants. With a fluorescence enhancement mechanism at play, the system boasts a dynamic range from 0 to 125 mM GHB in water, exhibiting a commendable limit of detection (LOD) at 7.3 mM. Crucially, its eco-friendly nature, devoid of solvent residuals, underscores its suitability as a proactive shield against chemical submission, embodying a beacon of hope in the fight against such insidious threats to public safety.

Biopsy-based histopathology and immunohistochemistry for cervical cancer detection are costly, time-consuming, and require expert personnel for data interpretation. We developed a simple magnetic nanoparticle (MNPs) and quantum dots (QD) coupled immuno nano fluorescence assay (MNPQDCINFA) for visual detection of HPV16-induced cervical cancer cells under UV light from cytology/biopsy samples exploiting host cancer cells expressing viral E7 protein as a biomarker. The E7 domain-specific polyclonal antibodies were generated against the 1–44 amino acid N-terminal (anti-domainN antibody) and 48–98 amino acid C-terminal domain (anti-domainC antibody). These antibodies were bioconjugated with nonfluorescent MNPs (60 % efficiency) and fluorescent QDs (66 % efficiency) to generate capturing (MNPs-anti-domainN antibody) and detecting (QDs-anti-domainC antibody) nano-complex, respectively. Assay conditions, such as concentration of capturing (20 μM) and detecting (50 nM) antibody nano-complexes and incubation duration (30 min), were standardized. The analytical sensitivity using pure HPV16 E7 protein was recorded up to 200 ng with very high specificity to differentiate from other HPV strains E7 proteins. The diagnostic performance characteristics with cytology samples showed 100 % sensitivity and specificity compared to immunofluorescence and biopsy-based histopathology analysis. The present invention can be effectively used for a quick, disposable, rapid cervical cancer cell detection system as an alternate test for immunofluorescence and histopathology.

A deep gold-coated sinusoidal grating is proposed as a transducer for label-free real-time biosensing, operating in a new configuration based on the optical switch effect, which produces complementary optical outputs enabling differential and referenced detection. Biosensing experiments are reported for the first time on this platform, using immunoassays involving biospecific pairs consisting of bovine serum albumin and its antibody, and human serum albumin and its antibody. Direct and sandwich immunoassays are demonstrated along with negative controls. A limit of detection of 6 pg/mm² was obtained. A theoretical model correlating the variation in the differential referenced output optical signal with adlayer growth is presented and supports the experimental results. The proposed detection device operating in the optical switch configuration makes a promising case for point-of-care detection applications because the differential detection of two diffracted orders enables common noise suppression and robust interrogation.

Capecitabine (CAP) is a chemotherapeutic agent used in cancer treatment, necessitating the development of sensitive and selective detection methods for its analysis in clinical samples. The present research utilized a simplified procedure for developing a novel electrochemical sensor based on a carbon paste electrode (CPE) modified with single-stranded DNA (ss-DNA), reduced graphene oxide (RGO), and molybdenum disulfide (MoS2). Unmodified (bare CPE) and modified (ss-DNA/RGO/MoS₂/CPE) electrodes were characterized by scanning electron microscopy (SEM), EDX analysis, and cyclic voltammetry (CV). Characterization data confirm the good conductivity and electrocatalytic nature with more electrochemically active sites in ss-DNA/RGO/MoS₂/CPE compared to bare CPE in the determination of CAP in real samples. Two linear ranges were obtained for CAP concentration within the ranges of 0.01–10.00 μM and 10.00–60.00 μM, with a detection limit of 0.0108 μM and a limit of quantification of 0.036 μM. The lower linear concentration range of 0.01–10.00 μM showed a sensitivity of 276.85 AM⁻¹ cm⁻², while the range of 10–60 μM had a sensitivity of 5.88 AM⁻¹ cm⁻². The performance of the modified electrode was tested in human serum samples, yielding satisfactory recovery results. The selectivity and practical ability of ss-DNA/RGO/MoS₂/CPE to determine CAP in the presence of different interfering species were investigated, demonstrating the sensor's selective, reliable, and accurate response.

A proposal has been made to identify tuberculosis cells using a novel compact sensor based on photonic crystal fiber: PCF in accordance with hexagonal spectroscopy. This proposed structure, which consists of a closely packed hexagonal air hole in the cladding region and a hollow-core area, possesses a very low loss of 6.30 × 10⁻⁸ dB/m and an exceptionally high sensitivity of up to 91.75 % (tuberculosis cell for 1.345). Numerous optical parameters have been identified and assessed, comprised of the numerical aperture, the V-parameter, or normalized frequency (V_eff), and the effective area (A_eff). The operational wavelength range is defined as 0.80–3.0 THz. The numerical investigation of the properties of the proposed TB sensors is performed within the environment of COMSOL Multiphysics (Version 5.3) using FV-FEM stands for the full vector finite element method. PCF sensors composed of hexagonal lattice in a circular form with ZEONEX as the backdrop material is intended to boost the sensitivity response in comparison to the earlier works. Additionally, the sensor that is being displayed achieves a single modality throughout its whole operational wavelength range. This proposed sensor may play a significant role in identifying tuberculosis thanks to its superior sensitivity response and extremely minimal confinement loss. So, it is clearly seen that this sensor could be used to bio-medical sectors with process of terahertz (THz) wave pulse.

In this study, a pioneering electrochemical sensor was developed for simultaneously determining nitrofurantoin (NFT) and furazolidone (FZD) residues in food and municipal wastewater samples. The sensor was prepared by integrating gold‑silver-alloy nanocoral clusters (Au-Ag-ANCCs) with zinc oxide nanoparticles (ZnO-NPs), carbon paste electrode (CPE) and polyethylene oxide (PEO) nanocomposites. The surface morphology and elemental compositions of Au-Ag-ANCCs/ZnO-NPs-CPE/PEO were characterized by FT-IR, XRD, SEM, EDX, EIS, and CV. The sensor showed exceptional performance over a wide linear range, from 1.0 pM to 250 μM for NFT and 0.9 nM to 360 μM for FZD. The detection and quantification limits were found to be 0.26 pM and 0.88 pM for NFT and 0.023 pM and 0.076 pM for FZD, respectively. In addition, the sensor exhibited excellent repeatability, reproducibility, selectivity, and long-lasting stability. When applied to the detection of AZM and ENF residues in poultry, fish, honey, dairy products and municipal wastewater, it exhibited excellent recoveries of 96.3–102.8% and relative standard deviations between 1.87% and 1.53%. In general, the developed sensor represents a significant advance in the fight against antibiotic residue pollution.