Qualitative Detection Research Articles

Comprehensive assessment of matcha qualities and visualization of constituents using hyperspectral imaging technology

Matcha, made from different tea leaves as raw material, exhibits diverse aromas and flavors. Therefore, there is an urgent need for a rapid, non-destructive method to assess the quality of matcha to ensure that these different characteristics are accurately assessed without compromising the integrity of the product. In this study, hyperspectral imaging technology (HSI) combined with machine learning methods enabled the first visual in situ assessment of matcha quality. The physicochemical contents of matcha were determined chemically. Qualitative and quantitative detection models for different types and grades were developed using HSI (containing Vis-NIR and NIR band). The results showed that hyperspectral data in the Vis-NIR were better than in the NIR band. The accuracy of XGBoost in modelling the classification of matcha grades reached 98.10 %. After feature selection using the random forest (RF) method, partial least squares regression (PLSR) was built to predicted the quality of matcha, which showed high prediction accuracy (test set Rp2 > 0.95). The model uses HSI to visually visualize spatial variations in constitutions (catechins, free amino acids, caffeine, soluble proteins, and soluble sugars) to show compositional differences between different types of matcha, providing a rapid non-destructive method for comprehensive assessment of matcha quality.

Self-reported exposure to blood and body fluids and serological evidence of lifetime exposure to hepatitis B virus among health care workers in Ghana: a cross-sectional study

IntroductionIn Sub-Saharan Africa alone, about 40–65% of Hepatitis B Virus infections among HCWs were a result of percutaneous occupational exposures to contaminated blood and body fluids of patients. Occupational exposure to blood and body fluids among healthcare workers is on the rise in Ghana. However, the relationship between self-reported exposures to blood and body fluids suspected to be contaminated with the hepatitis B virus and actual serological evidence of exposure remains unknown. The aim of the study however was to assess the self-reported exposure to HBV as against the serological evidence of lifetime exposure to HBV and associated factors among Ghanaian HCWs.MethodsThe study was a cross-sectional analytical survey that involved 340 HCWs who were recruited using a simple random sampling procedure from six cadres of staff from five districts in Greater Accra. The participants were surveyed using a validated instrument and 5mls of venous blood was aseptically withdrawn for qualitative detection of Anti-HBc. SPSS version 23.0 was used to analyze the data to obtain proportions, odds ratios and their corresponding confidence intervals with the level of significance set at 0.05.ResultsThe response rate was 94% with Nurses and Doctors in the majority with a mean age of 35.6 ± 7.2. Self-reported exposure to HBV was 63% whereas lifetime exposure to HBV (Anti-HBc) prevalence was 8.2% (95% CI = 5.0-11.0%). Females were 60% less likely to be exposed to HBV (aOR = 0.4; 95% CI = 0.1–0.9) than their male counterparts. HCWs without training in the prevention of blood-borne infections had almost three times higher odds of being exposed to HBV in their lifetime (aOR = 2.6; 95% CI = 1.0-6.4).ConclusionsThe findings of this study suggest that self-reported exposure to HBV-contaminated biological materials was high with a corresponding high lifetime exposure to HBV. The female gender was protective of anti-HBc acquisition. Apart from direct interventions for preventing occupational exposures to HBV in the healthcare setting, periodic training of all categories of healthcare workers in infection prevention techniques could significantly reduce exposure to the Hepatitis B virus.

Development and method validation of a sampling technique for a reproducible detection of synthetic cannabinoids in exhaled breath using an in vitro pig lung model.

Alternative matrices, especially exhaled breath (EB), have gained increasing attention for a few years. To interpret toxicological findings, knowledge on the toxicokinetic (TK) properties of a substance in EB is indispensable. Whilst such data are already accessible for various drugs (e.g. Δ9-tetrahydrocannabinol), they are still not available for new psychoactive substances, particularly synthetic cannabinoids (SCs). As SCs raise a high public health concern, the aim of this study was to assess these data in future TK studies in pigs. For this purpose, an in vitro sampling technique of EB was initially developed, being prospectively applied to anesthetized and ventilated pigs for the detection of SCs in a controlled and reproducible manner as exemplified by cumyl-5F-P7AICA. Furthermore, a method for the qualitative and quantitative detection of cumyl-5F-P7AICA in EB using glass fiber filters (GFF) was established und fully validated. Therefore, cumyl-5F-P7AICA (0.5 mg/mL in ethanol abs.) was initially nebulized using a ventilation machine and a breathing tube, as they are also used in surgeries. The aerosol was delivered into a simulated pig lung. To collect EB, a pump was connected to that part of the breathing tube, that contains EB (expiratory limb), and sampling was performed repeatedly (n=6) for 15 min (2 L EB/min) each using GFF. For extraction of the substance, the GFF were macerated with acetone and the remaining experimental components were rinsed with ethanol. After sample preparation, the extracts were analyzed by LC-MS/MS. In the complete experimental setup, about 40% of the initially nebulized cumyl-5F-P7AICA dose was found with 3.6 ± 1.3% being detected in the GFF. Regarding the comparably high loss of substance, the open ventilation system and a conceivable adsorption of the SC in the ventilator have to be considered. However, the herein introduced approach is promising to determine the TK properties of cumyl-5F-P7AICA in EB.

A colorimetric sensor array consisted of CaxMn1-xWO4 with high oxidase-like activity to detect antioxidants

Antioxidant detection is highly significant in practical applications. This study establishes an optical sensor array capable of simultaneous and convenient detection of multiple antioxidants in real samples. CaxMn1-xWO4 (CMW) synthesized via hydrothermal method with abundant surface oxygen vacancies and high internal electron transfer efficiency exhibits strong oxidase-like activity, which can oxidize TMB to blue product oxTMB using oxygen as reaction substrate. The presence of antioxidants weakens TMB oxidation, leading to a lighter blue color in the system. Therefore, CMW can be employed for colorimetric detection of antioxidants. Then CMW samples with varying Ca to Mn ratios were prepared, followed by the establishment of an optical sensor array. The detection systems were photographed, and PCA analysis of the RGB parameters was performed, enabling simultaneous qualitative and quantitative detection of nine kinds of antioxidants.

A dual-mode immunochromatographic sensor with photothermal and surface-enhanced Raman scattering for sensitive detection of aflatoxin B1

Multimodal lateral flow immunoassay has displayed the great potential to improve the flexibility and practicality of point-of-care testing. Herein, this study developed a dual-mode photothermal (PT) and surface-enhanced Raman scattering (SERS) immunochromatographic sensor for sensitive detection of aflatoxin B1 (AFB1). The bifunctional waxberry-like core-satellite nanoparticles loaded with 5,5′-Dithiobis (2-nitrobenzoic acid) (DTNB) were prepared and coupled with antibody to form PT@SERS nanoprobes for qualitative and quantitative detection of AFB1. The photothermal conversion efficiency and SERS enhancement factor of the nanoprobes were 42.11 % and 1.59 × 107, respectively. Under the optimal conditions, the limit of detection of PT assay was 0.033 ng/mL with a linear range of 0.05–10 ng/mL (R2 = 0.997); the limit of detection of SERS assay was 0.0073 ng/mL with a linear range of 0.005–10 ng/mL (R2 = 0.998). The results of the specificity analysis indicated no cross-reactions with the other toxins. The recoveries of the spiked corn and peanut were from 85.39 % to 112.15 % (PT assay) and 80.04 % to 106.57 % (SERS assay), respectively. The assay demonstrated that the developed dual-mode sensor provided a promising option for achieving the rapid detection of AFB1.

Formaldehyde contamination in seafood industry: an update on detection methods and legislations.

Seafood is abundant in high-quality protein, healthy fats (n-3 and n-6 PUFAs), minerals (calcium, magnesium, copper, selenium, and so on), and vitamin D. Functional compounds in seafood can protect against lifestyle-related diseases. Having had all the merits mentioned, it is also a highly putrefiable food item. To maintain quality and prolong seafood's shelf life, various chemicals have been added, including nitrite, sulfur dioxide, and formaldehyde. In this review, we summarize the uses, the incidence of added formalin contamination, and the approved limit for seafood products. Additionally, worldwide regulations or standards for the use of formalin in seafood products, as well as recent changes relevant to new methods, are highlighted. Although strict limits and regulations have been placed on the utilization of formaldehyde for seafood preservation, there are few incidences reported of formalin/formaldehyde detection in seafood products around Asian countries. In this context, various qualitative and quantitative detection methods for formaldehyde have been developed to ensure the presence of formaldehyde within acceptable limits. Besides this, different rules and regulations have been forced by each country to control formaldehyde incidence. Although it is not an issue of formaldehyde incidence in European countries, strict regulations are implemented and followed.

Molecular analysis of changes in DNA binding affinity and bending extent induced by the mutations on the aromatic amino residues in Cren7.

Proteins from Crenarchaeal organisms exhibit remarkable thermal stability. The aromatic amino acids in Cren7, a Crenarchaeal protein, regulate protein stability and further modulate DNA binding and its compaction. Specific aromatic amino acids were mutated, and using spectroscopic and theoretical approaches, we have examined the structure, DNA binding affinity, and DNA bending ability of mutants. and compared with wild-type (WT) Cren7. The reverse titration profiles were analysed by a noncooperativeMcGhee-von Hippel model to estimate affinity constant (Ka) and site size (n) associated with binding to the DNA. Biolayer interferometry (BLI) measurements showed that the binding affinity decreased at higher salt concentrations. For theoretical analysis of extent of DNA bending, radius of gyration and bending angle were compared for WT and mutants. Time evolution of order parameters based on translational and rotational motion of tryptophan residue (W26) was used for qualitative detection of stacking interactions between W26 of Cren7 and DNA nucleobases. It was observed that orientation of W26 in F41A favoredformation of a new lone pair-lone pair interaction between DNA and Cren7. Consequently, in thermostable proteins, the aromatic residues at the terminus maintain structural stability, whereas the residues at the core optimize the degree of DNA bending and compaction.

Qualitative discrimination and quantitative prediction of salt in aqueous solution based on near-infrared spectroscopy

Freshwater resources have been gradually salinized in recent years, dramatically impacting the ecosystem and human health. Therefore, it is necessary to detect the salinity of freshwater resources. However, traditional detection methods make it difficult to check the type and concentration of salt quickly and accurately in solution. This paper uses a portable near-infrared spectrometer to qualitatively discriminate and quantitatively predict the salt in the solution. The study was carried out by adding ten salts of NaCl, KCl, MgCl2, CaCl2, Na2CO3, K2CO3, CaCO3, Na2SO4, K2SO4, MgSO4 to 2 milliliters of deionized water to prepare a single salt solution (0.02% - 1.00%) totaling 100 sets. It was found that the Support vector machine (SVM) model was only effective in discriminating the class of salt anions in the solution. The Partial least squares-discriminant analysis (PLS-DA) model, on the other hand, can effectively discriminate the classes of salt in solution, and the accuracies of the optimal model prediction set and the interactive validation set are 98.86% and 99.66%, respectively. Furthermore, the Partial least squares regression (PLSR) models can accurately predict the concentration of NaCl, KCl, MgCl2, CaCl2, Na2CO3, K2CO3, CaCO3, Na2SO4, K2SO4, MgSO4 salt solutions. The coefficients of determination R2 of their model interactive validation sets were 0.99, 0.99, 0.99, 0.97, 0.99, 0.99, 0.98, 0.99, 0.98, and 0.98, respectively. This study shows that NIRS can achieve rapid and accurate qualitative and quantitative detection of salts in solution, which provides technical support for the utilization of safe water resources.

Electroreduction of CO2 by Hybrid Cu‐TiO2/rGO Catalyst: Qualitative Detection of Products using Rotating Ring Disc Electrode

AbstractThe electrochemical reduction of CO2 (ERCO2) to valuable chemicals such as acetic acid/acetate offers a promising route to revolutionize chemical production and enhance sustainability. Here, we report the hydrothermal preparation of an electrocatalyst consisting of copper/titanium dioxide/reduced graphene oxide (Cu‐TiO2/rGO) for ERCO2 in aqueous medium. The metal‐support (TiO2/rGO) was pre‐synthesized by combining an aqueous solution of TiO2 and GO in an autoclave at 150 °C for 20 h. Then TiO2/rGO was added to synthesized Cu colloid formed through the reduction of copper (II) nitrate trihydrate resulting in the formation of Cu‐TiO2/rGO. The Cu‐TiO2/rGO hybrid nanocomposite was fully characterized using spectroscopic and microscopic techniques. This study explored the versatility of the rotating ring‐disc electrode (RRDE) as an in situ electroanalytical tool for the selective detection of products formed during ERCO2. The well‐designed hybrid electrocatalyst, containing Cu0/Cu+ active sites, facilitated the eight‐electron transfer for acetic acid (AA) formation at low potentials. AA formation was detected on the RRDE and validated by conventional NMR and HPLC techniques. This work highlights and expands the scope of selective hydrogenation of CO2 towards value‐added products.

Identification of horse ingredients based on recombinase polymerase amplification, high-throughput DNA isolation and magnetic separation

Adulteration of meat products remains a significant issue worldwide. In this study, we developed a high-throughput, rapid, sensitive, and selective method for qualitative and quantitative detection of horse meat adulteration in meat products. This method, which is not only innovative but also highly practical, involves coupling a 96-well high-throughput DNA isolation process with recombinant enzyme polymerase amplification (RPA), magnetic separation (MS), and high-throughput fluorescence detection (FD). We designed a set of primers targeting the mitochondrial ATP6-8 gene of horses. The upper and lower primers were labeled with 6-FAM fluorescent moiety and biotin, respectively. Following RPA amplification, the amplicons were separated and purified using streptavidin-modified magnetic beads (MB@SA). Subsequently, the amplicons were qualified and quantified using a high-throughput fluorescence detection system. We optimized the conditions for primer addition, incubation time, and the ratio of amplicon to MB@SA. Our results showed that a fluorescence threshold of 834 indicated positive detection. The method exhibited high specificity, with no positive amplification observed in DNA from the other 11 types of meat. It demonstrated high sensitivity and was capable of detecting as little as 0.1% (wt%) of horse meat in adulterated samples. Combined with our developed 96-well high-throughput DNA extraction system, the RPA-MS-FD assay process could analyze 96 samples in 31.5 min, including 11.5 min for rapid DNA extraction, 15 min for RPA amplification, and 5 min for fluorescence detection. Finally, we successfully applied this assay to analyze 21 commercial meat products, proving its practicality and effectiveness.

Design and preparation of a fluorescent molecularly imprinted membrane for the selective detection of pepsin enzyme as a biomarker for gastroesophageal reflux disease

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.

BCMFIFuse: A Bilateral Cross-Modal Feature Interaction-Based Network for Infrared and Visible Image Fusion

The main purpose of infrared and visible image fusion is to produce a fusion image that incorporates less redundant information while incorporating more complementary information, thereby facilitating subsequent high-level visual tasks. However, obtaining complementary information from different modalities of images is a challenge. Existing fusion methods often consider only relevance and neglect the complementarity of different modalities’ features, leading to the loss of some cross-modal complementary information. To enhance complementary information, it is believed that more comprehensive cross-modal interactions should be provided. Therefore, a fusion network for infrared and visible fusion is proposed, which is based on bilateral cross-feature interaction, termed BCMFIFuse. To obtain features in images of different modalities, we devise a two-stream network. During the feature extraction, a cross-modal feature correction block (CMFC) is introduced, which calibrates the current modality features by leveraging feature correlations from different modalities in both spatial and channel dimensions. Then, a feature fusion block (FFB) is employed to effectively integrate cross-modal information. The FFB aims to explore and integrate the most discriminative features from the infrared and visible image, enabling long-range contextual interactions to enhance global cross-modal features. In addition, to extract more comprehensive multi-scale features, we develop a hybrid pyramid dilated convolution block (HPDCB). Comprehensive experiments on different datasets reveal that our method performs excellently in qualitative, quantitative, and object detection evaluations.

The role of human papillomavirus in laryngeal carcinoma using PCR

<b>Introduction:</b> The etiology of laryngeal carcinoma is multifactorial. Smoking and alcoholism are well-known risk factors; however, recently oncogenic human papillomavirus has been suggested to promote carcinogenesis. PCR has had the most dramatic impact on molecular biology, enabling the amplification of specific regions of interest and detection of gene sequences.<b>Aim:</b> The aims are to evaluate the possible relationship between laryngeal carcinoma and human papillomavirus and its impact on the socio-demographic findings and the clinicopathological presentation.<b>Material and method:</b> Twenty-five patients with laryngeal carcinoma were included. Two biopsies were taken from every patient, the first from the main bulk of the tumor, the second from the normal surrounding mucosal tissues and considered as a control group. Virus detection was done by PCR test. The HPV screen test is an <i>in vitro</i> nucleic acid amplification test for qualitative detection of HPV type (16, 18, 31, 33, 35, 39, 45, 52, 53, 56, 58, 59, 66, and 70) and β-globin gene used as internal control. Samples were transferred into the thermal cycler, in which denaturation, annealing, and chain elongation occurred. Specific bands of HPV were detected using a high-resolution Cannon camera.<b>Results:</b> The average age of the patients was 60.8 years. Twenty-three patients (92%) were males. Viral DNA was detected in 8% of patients, representing genotypes (16, 18, 31, 33, 35, 39, 45, 52, 53, 56, 58, 59, 66, and 70). There is no statistically significant relationship between the presence of the virus and epidemiological and clinic-pathological features except for female gender distribution (P-value = 0.022).<b>Conclusions:</b> There is no significant relationship between laryngeal carcinoma and human papillomavirus, nor a significant impact on socio-demographic findings and clinicopathological presentation.

Changing trends in anabolic-androgenic steroid use within Scottish prisons: Detection, prevalence, and quantitation.

Anabolic-androgenic steroids (AASs) are a subclassification of image performance enhancing drugs (IPEDs). While AAS use is most prevalent among people in athletics, there is also high lifetime prevalence of AAS use among prisoners. This study reports the qualitative detection of AASs in seized samples from the Scottish prisons from 2019-2023. Additionally, methods were developed for the quantitative analysis of AASs using gas chromatography-mass spectrometry (GC-MS) and applied to 61 samples of tablets or powders seized from Scottish prisons between July 2022 and July 2023. Since 2022, there has been an increase in AAS detections in the Scottish prisons. Oxymetholone was the most prevalent AAS, followed by metandienone (methandrostenolone, methandienone), methyltestosterone, oxandrolone, mestanolone (methylandrostanolone), stanozolol, and androstenedione. Multiple AASs were found in 21 samples and 10 samples contained other drugs, including amitriptyline, sertraline, zopiclone, mirtazapine, sildenafil, etizolam, Δ9-tetrahydrocannabinol, and the synthetic cannabinoid MDMB-INACA. Most AAS samples were tablets (77.0%), although they were also detected in powders, herbal material, e-cigarettes, and a fragmented soap bar-type sample. There was a large variation in the concentration of AASs in the tablets and powders seized from the Scottish prisons, demonstrating AASs are another highly variable component of the polydrug use situation in prisons, the effects of which need to be examined further.

Gold Nanocluster-Based Self-Assembly Fluorescence Microbeads for Sensor Array Discrimination of Multicomponent Metal Ions.

Benefiting from easy visualization and simultaneous detection of multiple targets, fluorescence microbeads are commonly used as fluorescence-sensing elements to detect pollutants in the environment. However, the application of fluorescence microbead-based sensor arrays is still limited because fluorescence dyes always suffer from self-quenching, photobleaching, and spectral overlap. Herein, three kinds of gold nanoclusters (Au NCs) were assembled with polystyrene microspheres (PS NPs) by electrostatic interaction to prepare fluorescence microbeads (PS-Au NCs), developing a sensor array for the simultaneous analysis of multiple metal ions. In this work, different PS-Au NCs showed an enhancing or quenching fluorescence response to various metal ions, owing to distinct binding capacities. Combined with the recognition algorithm from linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA), this sensor assay could realize single-component and multicomponent qualitative detection for 8 kinds of heavy metal ions (HMIs) including Cu2+, Co2+, Pb2+, Hg2+, and Ce3+. Particularly, the large surface area of PS NPs could provide a direct reaction microenvironment to improve the efficiency of the detection process. Meanwhile, the fluorescence property of Au NCs could also be enhanced by a partially effective aggregation-induced emission (AIE) effect to give better fluorescence signal output. Under optimal conditions, 8 kinds of heavy metals and their multicomponent mixtures could be identified at concentrations as low as 0.62 μM. Meanwhile, the analytical performance of this sensor assay in water samples was also verified, meeting the requirement of actual analysis. This study provides a great potential and practical example of single-batch, multicomponent identification for HMIs.

Factors associated with elevated SARS-CoV-2 immune response in children and adolescents.

Understanding the distinct immunologic responses to SARS-CoV-2 infection among pediatric populations is pivotal in navigating the COVID-19 pandemic and informing future public health strategies. This study aimed to identify factors associated with heightened antibody responses in children and adolescents to identify potential unique immune dynamics in this population. Data collected between July and December 2023 from the Texas Coronavirus Antibody REsponse Survey (Texas CARES), a statewide prospective population-based antibody survey among 1-to-19-year-old participants, were analyzed. Each participant had the following data available for analysis: (1) Roche Elecsys® Anti-SARS-CoV-2 Immunoassay for Nucleocapsid protein antibodies (Roche N-test), (2) qualitative and semi-quantitative detection of antibodies to the SARS CoV-2 spike protein receptor binding domain (Roche S-test), and (3) self-reported antigen/PCR COVID-19 test results, vaccination, and health status. Statistical analysis identified associations between participant characteristics and spike antibody quartile group. The analytical sample consisted of 411 participants (mean age 12.2 years, 50.6% female). Spike antibody values ranged from a low of 6.3 U/ml in the lowest quartile to a maximum of 203,132.0 U/ml in the highest quartile in the aggregate sample. Older age at test date (OR = 1.22, 95% CI: 1.12, 1.35, p < .001) and vaccination status (primary series/partially vaccinated, one or multiple boosters) showed significantly higher odds of being in the highest spike antibody quartile compared to younger age and unvaccinated status. Conversely, fewer days since the last immunity challenge showed decreased odds (OR = 0.98, 95% CI: 0.96, 0.99, p = 0.002) of being in the highest spike antibody quartile vs. more days since last immunity challenge. Additionally, one out of every three COVID-19 infections were asymptomatic. Older age, duration since the last immunity challenge (vaccine or infection), and vaccination status were associated with heightened spike antibody responses, highlighting the nuanced immune dynamics in the pediatric population. A significant proportion of children/adolescents continue to have asymptomatic infection, which has important public health implications.

An Fe3O4-Au heterodimer nanoparticle-based lateral flow assay for rapid and simultaneous detection of multiple influenza virus nucleic acids.

Sensitive, convenient and rapid detection and subtyping of influenza viruses are crucial for timely treatment and management of infected people. Compared with antigen detection, nucleic acid detection has higher specificity and can shorten the detection window. Hence, in this work, we improved the lateral flow assay (LFA, one of the most promising user-friendly and on-site methods) to achieve detection and subtyping of H1N1, H3N2 and H9N2 influenza virus nucleic acids. Firstly, the antigen-antibody recognition mode was transformed into a nucleic acid hybridization reaction. Secondly, Fe3O4-Au heterodimer nanoparticles were prepared to replace frequently used Au nanoparticles to obtain better coloration. Thirdly, four lines were arranged on the LFA strip, which were three test (T) lines and one control (C) line. Three T lines were respectively sprayed by the DNA sequences complementary to one end of H1N1, H3N2 and H9N2 influenza virus nucleic acids, while Fe3O4-Au nanoparticles were respectively coupled with the DNA sequences complementary to the other end of H1N1, H3N2 and H9N2 nucleic acids to construct three kinds of probes. The C line was sprayed by the complementary sequences to the DNAs on all three kinds of probes. In the detection, by hybridization reaction, the probes were combined with their target nucleic acids which were captured by the corresponding T lines to form color bands. Finally, according to the position of the color bands and their grey intensity, simultaneous qualitative and semi-quantitative detection of the three influenza virus nucleic acids was realized. The detection results showed that this multi-channel LFA had good specificity, and there was no significant cross reactivity among the three subtypes of influenza viruses. The simultaneous detection achieved comparable detection limits with individual detections. Therefore, this multi-channel LFA had good application potential for sensitive and rapid detection and subtyping of influenza viruses.

Qualitative Phytochemical Detection of Ethanolic Leaf Extract of Two Medicinal Plant Such as Ocimum basilicum and Coleus amboinicus

Study on phytochemical detection of ethanoic leaf by qualitative analysis focuses on the presence of phytochemicals in two different plant leaves. Ocimum basilicum and Coleus amoboinicus the findings are expected to contribute to the development of natural products and enhance the utilization of plant as a medicine.The method of extraction using ethanol as a solvent is attributed to its efficacy in extracting broad spectrum of phytochemicals, ensuring the comprehensive analysis of the bioactive constituents present in these plants. Preliminary phytochemical tests are being carried out by following standard procedure. Qualitative analysis revealed that Coleus amboinicus contained alkaloids, betacyanin, carbohydrates, Flavonoids, Cardiac glycosides, Phenol,and Starch. In contrast Ocimum basilicum exhibited a broad spectrum including Alkaloids, Anthocyaninand betacyanin, carbohydrates, Coumarine, Flavanoids, Cardiac glycosides, phenols, Saponins, Starch, Tannins, Terpenoids. The findings highlight the diverse bioactive compounds present in the leaves consideredfir studyshows their potential in the development of medicinal agricultural and cosmetics products.Further research in these phytochemicals such as terpenoids, terpenes in herbal plants as insecticide is recommended for sustainable agricultural practices.

Performance evaluation of microfluidic microplate-based fluorescent ELISA for qualitative detection of SARS-CoV-2–specific IgG and IgM

We evaluated the diagnostic performance of newly developed microfluidic microplate-based fluorescent ELISA for anti-SARS-CoV-2 antibody detection: the Veri-Q opti COVID-19 IgG and IgM ELISAs (hereafter, “Opti IgG/M”; MiCo BioMed, Gyeonggi-do, Republic of Korea), in comparison with conventional ELISAs. A total of 270 serum samples were analyzed, among which 90 samples were serially obtained from 25 COVID-19 patients. Another 180 samples were collected from 180 SARS-CoV-2–negative individuals. As comparative assays, we used SCoV-2 Detect IgG/M ELISA (hereafter, “InBios IgG/M”; InBios, Seattle, WA, USA) and Veri-Q COVID-19 IgG/IgM ELISA (hereafter, “Veri-Q IgG/M”; MiCo BioMed). Compared with conventional ELISAs, the Opti IgG yielded 97.1–100.0% positive percent agreement, 95.2–98.0% negative percent agreement, 96.3–97.8% total percent agreement, and kappa values of 0.90–0.94. Between the Opti IgM and the InBios IgM, the values were 93.7%, 96.6%, 95.9%, and 0.89, respectively. For the Opti IgG, sensitivities for the samples collected from 0–7, 8–14, 15–21, and ≥ 22 days after symptom onset were 40.0, 58.3, 94.1, and 100.0%, respectively. The values for the Opti IgM were 30.0, 54.2, 88.2, and 80%, respectively. The diagnostic specificities of the Opti IgG and IgM were 99.4 and 97.2%, respectively. The microfluidic microplate-based fluorescent ELISAs showed comparable diagnostic performance to conventional ELISAs for detecting anti-SARS-CoV-2 antibodies. With the combination of high throughput, a simplified workflow, and the ability to analyze reduced volumes, this new technology has great potential for improving SARS-CoV-2 serologic testing.

Molecular genetic characterization of hepatitis B virus in blood donors from South Vietnam

The problem of transfusion safety preventing parenteral viral hepatitis transmission remains relevant. Viral hepatitis B (HB) is the most common viral infection transmitted through transfusion procedures. One of the natural phases of a chronic viral hepatitis B (CHB) course is occult hepatitis B infection (OBI) characterized by undetectable HBsAg level (regardless of other serological marker levels) along with detected hepatic HBV DNA as well as blood viral load ranging from extremely low to undetectable. In Vietnam, prevention of transfusion-based HBV transmission is focused on donor screening; it is still based solely on HBsAg serology. As such, OBI remains a potential threat to blood transfusion safety. Assessing hepatitis B virus (HBV) DNA is a reliable preventive measure against HBV transmission from HBsAg– donors, especially in highly endemic regions. The aim of our work was HBV identification and molecular genetic characterization in blood donors from South Vietnam. The study material was presented by 500 donor serum samples. Subjects were examined for HBV markers with qualitative detection of HBsAg, HBs IgG, and HBcore IgG. Amplification and subsequent HBV sequencing were performed using nested PCR with overlapping primer pairs jointly flanking the complete HBV genome (S, P, C, X genes). Full-size HBV genome nucleotide sequences were obtained for 58 samples. Among blood donors, taking into account HBsAg+ and HBsAg– samples, HBV DNA was detected in 11.6%, including 8.6% OBI. HBV phylogenetic analysis showed genotypes B and C. Vaccine escape mutations and mutations that contribute to disease progression were identified. Current screening in Vietnam is insufficient for eliminating the risk of transfusion-transmitted HBV infection. The major risk factor is OBI. PCR testing for HBV should be considered for blood donor screening.