Talanta Open最新文献

Objectives

Meningitis is a medical emergency, and it is crucial to diagnose it accurately and promptly in order to manage patients effectively. It would, therefore, be essential to introduce and have fast, accurate, and user-friendly methods to determine the cause of these infections. This study aimed to demonstrate a potentially cost-effective new approach for detecting meningitis using a paper-based vertical flow microarray, which could be useful in settings with limited resources.

Methods

We describe a multiplex paper microarray for detecting Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, and Salmonella spp. by the passive vertical flow of PCR-amplified clinical samples. A multibiotinylated amplicon was obtained as a product of PCR in the presence of both a biotinylated primer and biotin-11-dUTP. An enhancement step based on an enzyme-free gold enhancement protocol was also used to facilitate visual detection.

Results

This study showed that the vertical flow microarray (previously evaluated for one pathogen) can discriminately detect the amplification results down to the 10² copies of DNA limit for four meningitis pathogens in a multiplexed set-up. The study further demonstrated the ability of this device and setup to detect three of the four pathogens from clinical biosamples.

Discussion

This study demonstrated the capacity of a vertical flow microarray device to detect amplification products for four prevalent meningitis pathogens in a multiplex format. The vertical flow microarray demonstrated consistent visualization of the expected gene amplification results; however, indicating limitations in the pre- and amplification steps. This study highlights the potential of this multiplexing method for diagnosing meningitis and other syndromic diseases caused by various pathogens, especially in resource-limited areas.

Sensitive, simple, and accurate spectrophotometric methods have been developed for the assay of arrhythmias drug-dronedarone hydrochloride (DND) in bulk drug and pharmaceutical formulations. The proposed method is based on the oxidation reaction of DND with a known excess of cerium(IV) ammonium sulfate (Ce(IV)) as an oxidizing agent in acid medium, followed by the determination of the unreacted oxidant by adding a fixed amount of dye, e.g., amaranth (AM), methylene blue (MB), and indigocarmine (IC), followed by measuring the absorbance at 520, 664, and 610 nm, respectively. The effects of experimental conditions were studied and optimized. The beer's law was obeyed in the concentration ranges of 1.0–10, 1.0–15, and 1.0–8.0 μg mL^-1 using AM, MB, and IC dyes, respectively, with a correlation coefficient ≥ 0.9992. The calculated molar absorptivity values are 3.6527 × 10⁴, 3.1212 × 10⁴, and 4.229 × 10⁴ L mol^-1 cm^-1 using AM, MB, and IC dyes, respectively. The limits of detection and quantification were 0.30 and 1.0 µg mL^-1, respectively, for the three methods. Intra-day and inter-day accuracy and precision of the methods have been evaluated. No interference was observed from the additives. The proposed methods were successfully applied to the assay of DND in tablet preparations and the results were statistically compared with those of the reported method by applying Student's t-test and F-test. The reliability of the methods was further ascertained by performing recovery studies using the standard addition method.

Globally, trace metals toxicity in wastewater poses health problems for humans even at truncated concentrations and warrants investigation. This review study focuses on the suitable cutting-edge advancements in nanotechnology-based electrochemical sensor technology for the apprehension of selected toxic metal ions such as arsenic(As), cadmium(Cd), chromium(Cr), lead(Pb), and uranium(Ur)) in wastewater samples. The discussion includes an examination of synthesis techniques for sensors based on Nanomaterials (NMs). Moreover, these electrochemical sensors are scrutinized to study the complex principles that describe their problem solving achievement, such as susceptibility, determination limit, duplicability, repeatability, and selectivity in wastewater matrices for trace metal detection. Most importantly, the discussion also considers the interactions between NMs, electrochemistry, and sensing mechanisms, providing a comprehensive view of the cooperative developments promoting improved advanced sensor technology. This review critically investigates the existing literature to assess and capture the progress landscape of nano-based electrochemical sensors. Ultimately, this review paper could significantly play a role towards the use of these attractive nano-based electrode materials in revamping paradigms for environmental monitoring and advancing precision in trace metal sensing in wastewater.

Paper-based microfluidics has emerged as a promising field with diverse applications ranging from medical diagnostics to environmental monitoring. Despite significant progress in research and development, the translation of paper-based prototypes into practical end-user devices remains limited. This limitation stems from challenges related to devices not being sufficiently portable and autonomous, which paper-based microfluidics is expected to overcome. Yet for this purpose, we note the lack of comprehensive numerical modeling tools capable of simulating the intricate physicochemical phenomena involved in order to optimize the development process; hence, in this study, we introduce porousMicroTransport, a novel simulation package integrated with the open-source platform OpenFOAM®, designed to address these challenges. porousMicroTransport offers efficient solvers for fluid flow and transport phenomena in microfluidic porous media, including capillarity models and (bio)chemical reactions. Moreover, under horizontal flow conditions, porousMicroTransport application field can be extended to any porous media. We demonstrate the software’s effectiveness in two example cases, showcasing its ability to accurately reproduce complex phenomena involved in paper-based devices. By virtue of being an easy-to-use and computationally efficient tool, porousMicroTransport facilitates the design and optimization of devices, potentially enabling more devices to meet the WHO’s REASSURED criteria for point-of-care testing. We anticipate that this tool will accelerate the development and deployment of robust and portable diagnostic devices, bridging the gap between research and practical applications.

Silver nanoparticles (AgNPs)-Chitosan (Chi) functionalized cysteine (cys)-SAM (self-assembled monolayer) based electrochemical, label free, ultrasensitive, non-invasive immunosensing nanomolecular platform has been fabricated for the detection of novel OC biomarker S-100. This has been achieved through bio-functionalization of AgNPs-Chi/cys/mini gold slides by covalent immobilization of anti-S100 antibodies. Cyclic voltammetric (CV) studies establish successful fabrication of anti-S100/AgNPs-Chi/Au nanomolecular platform. Differential pulse voltammetric (DPV) measurements reveal that anti-S100/Chi-AgNPs/Au is able to sense 50 fg mL^-1 – 500 ng mL^-1 of S100 in buffer and in spiked saliva samples within 120 s interaction time having improved favorable shelf life and specificity. The fabricated platform is very selective and able to detect S100 in OC patient/s saliva samples warrants realization of simple non-invasive electrochemical immunosensor for in situ or on-site applications (especially for remote areas) for early diagnosis of OC while offering bio-compatibility at low cost.

Although several luminescent-based nanostructured materials are used as cellular imaging probes, creating a biocompatible subcellular imaging probe can be challenging. Instantaneously, it is crucial and urgently needed for certain fluorescent nanoprobes to identify possibly harmful heavy metal ions. We present a straightforward one-pot preparation of bright orange emissive (quantum yield approximately 16 %) Nitrogen/Sulfur co-doped carbon dots (N/S CDs) from citric acid and methylene blue as raw materials that will serve as a specific Cr(VI) ions sensor and an effective mitochondrial labeling in cancer cells. They had several benefits including low ecological impact, facile synthesis, good water solubility, photostability, and high stability. We found that N/S CDs photoluminescence (PL) could be reduced when Cr(VI) ions were present near them, and the PL reduction occurred highly sensitively to the presence of Cr(VI) compared to other metal ions including Cr(III) ions. This specific reduction of PL was due to the non-fluorescent complex formation through the inner filter effect (IFE). The established fluorescence-based sensing technique could serve for Cr(VI) ion quantification with exceptional sensing efficiency in the wide linear range of 7 to 70 μM (R₂ = 0.9873), with the limit of detection of 53.5 nM. It was also revealed that the current fluorescent probe could be encouragingly utilized to quantify the concentration of Cr(VI) ions in various water specimens such as tap water. In addition, they were shown to function as a mitochondria-targeting nanoprobe in human cancer cells (ME 180 cells and Hela cells) for cell imaging. Concludingly, it was envisioned that these fluorescent nanoprobes could find a use in real-time monitoring of Cr(VI) ions in water-based ecosystems with ultrahigh sensitivity and cell image tracking via mitochondria labeling as biocompatible nanoprobes.

A novel fluorescent molecularly imprinted polymer membrane (FMIM) has been developed for the selective binding and qualitative detection of pepsin enzyme, a biomarker indicative of gastroesophageal reflux disease (GERD). This study utilises the high selectivity offered by molecular imprinting techniques to capture pepsin enzyme within complex biological matrices, such as human saliva. Additionally, fluorescent carbon dots integrated into the membrane matrix provide instant visual detection of pepsin. Various combinations of functional monomers and cross-linkers were systematically evaluated to investigate their impact on the binding capacity and mechanical stability of the resultant FMIMs. The optimum performance was achieved with a mixture of two hydrophilic monomers, namely N-(hydroxymethyl)acrylamide and acrylamide, in conjunction with N,N-methylenebis(acrylamide) as the cross-linking agent. The developed FMIM demonstrated a binding capacity of 21.56 mg g^-1, surpassing that of the fluorescent non-imprinted membrane (FNIM) at 8.49 mg g^-1. Moreover, the binding of FMIM to pepsin was tested against other competitor enzymes to verify its selectivity. Furthermore, comprehensive characterisation of both FMIM and FNIM was conducted using various analytical techniques to ensure their structural integrity and functionality. Ultimately, the developed FMIM exhibited effective binding of pepsin in standard solutions and samples, enabling enrichment and visual detection of the biomarker enzyme.

The 2018 Agricultural Improvement Act federally legalized the cultivation of hemp and manufacture and sale of cannabidiol (CBD). The overproduction of CBD led to a significant drop in price. To maintain profitability, manufacturers began producing synthetic and semi-synthetic cannabinoids, marketing them as “legal” and “hemp-derived” due to their synthesis from CBD. The cannabis industry is adaptable, and laboratories have struggled to keep up with the rapid emergence of new compounds. This has resulted in products with unlabeled or mislabeled cannabinoids, causing unexpected adverse events. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the separation and quantitation of 21 cannabinoids. The method was applied in the analysis of 55 commercially available products. Results demonstrate significant issues with quality assurance and labeling in the unregulated cannabis market. Many products either did not contain the cannabinoids listed on their labels or contained cannabinoids that were not listed. When cannabinoids were present, their concentrations were often incorrect, with some products showing high concentrations that could pose a potential health risk. Moreover, safety, dosing, and other pharmacological data of these newly proliferated cannabinoids are lacking. Reports of adverse events are increasing to poison controls centers and emergency departments following cannabis product use. Often, the actual cannabinoids involved in the case reprots are not determined. It is critical to develop more comprehensive testing methodologies to determine the content of cannabis products and to implement stronger quality assurance measures and regulations to protect the public from low-quality and potentially dangerous products.

Carbon Quantum Dots from Natural Sources (NACQDs) is a novel type of carbon-based material that have garnered significant attention due to their remarkable features, including luminescence, photostability, nanoscale size, water solubility, low toxicity, biocompatibility, and cost-effectiveness. The synthesis of NACQDs involves a diverse range of natural sources, such as fruits, foods, beverages, human and animal derivatives, vegetables, leaves, and waste materials. Various synthesis methods, including electrochemical approach, chemical oxidation, hydrothermal carbonization, ultrasonic techniques, microwave-assisted synthesis, solvothermal method, laser ablation technique, thermolysis, and atmospheric plasma-based synthesis, have been explored to tailor the size and properties of NACQDs. Characterization techniques like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TЕM), ultraviolet absorption, fluorescence properties, and nuclear magnetic resonance (NMR) have provided invaluable insights into the physical and chemical characteristics of NACQDs. This review highlights the immense potential of NACQDs in metal ion sensing applications and underscores the need for further investigation to enhance their reproducibility and precise control over their properties. NACQDs hold great promise as versatile nanomaterials for metal ion sensing and are poised to revolutionize diverse fields, ranging from environmental monitoring to biomedical diagnostics and chemical analysis.