Search Results (375)

Foot-and-mouth disease (FMD) is one of the most infectious viral diseases of cloven-hoofed animals. The crucial strategy for FMD control is the combination of animal quarantine and a rapid onsite diagnostic assay capable of differentiation of infected from vaccinated animals (DIVA). Herein, we have developed a lateral flow immunoassay to detect specific antibodies against FMDV non-structural protein (NSP), based on recombinant mu3ABC produced by E. coli as an antibody detector, the so-called mu3ABC strip test. The performance of this test was examined using 366 field serum samples from cattle, pigs, and goats and compared with the commercial ELISA kit, resulting in a diagnostic sensitivity (DSn) and specificity (DSp) of 98.05% and 93.16%, respectively. Additionally, efficacies of this test and commercial ELISA were determined using 200 reference bovine serum samples (100 positives, 100 negatives) classified by the Regional Reference Laboratory for Foot-and-Mouth Disease in South East Asia (RRL). The result reveals that the DSn and DSp of the test were 78% and 91%, respectively, while those for the commercial ELISA kit were 69% and 100%, respectively. The developed mu3ABC strip tests are effective and can be used to differentiate the infected animals in parallel with the sero-surveillance ELISA test. Full article

The emergence of highly pathogenic avian influenza viruses (AIVs) poses significant threats to global public health and the poultry economy. Rapid detection methods targeting the hemagglutinin (HA) protein have become increasingly unreliable due to ongoing antigenic drift and genetic mutations. In this study, we screened two monoclonal antibodies (mAbs) against the highly conserved neuraminidase (NA) protein, which were characterized by high affinity and specificity for the N9 subtype. Using the paired mAbs 12A2 and 12F12, an NA-targeting lateral flow immunoassay (NA-LFIA) was developed for the rapid detection of N9 subtype AIVs. The NA-LFIA demonstrated exceptional specificity, exhibiting no cross-reactivity with the N1, N2, or N6 subtypes. The limits of detection (LODs) were established at 10^3.3 TCID₅₀/0.1 mL for the virus and 98 ng/mL for the recombinant NA protein. The test strips exhibited excellent reproductivity for detecting the NA antigen, with intra-assay and inter-assay variations of 5.32% and 6.05%, respectively. Stability testing confirmed a six-month shelf life without any loss of sensitivity. These finds indicate that the NA-LFIA is a robust, rapid point-of-care testing (POCT) tool for the early detection of N9 subtype AIV infection. Full article

Early detection of lung cancer remains challenging due to the extremely low concentrations of disease-specific biomarkers, which limit the development of highly sensitive and reliable point-of-care (PoC) diagnostic devices. Electrochemical biosensors integrating graphene oxide (GO) and gold nanoparticles (AuNPs) have emerged as promising platforms for the rapid, sensitive, and selective detection of lung cancer biomarkers, enabling more timely diagnosis. Biomarkers such as carcinoembryonic antigen (CEA), cytokeratin-19 fragments (CYFRA 21-1), neuron-specific enolase (NSE), and circulating tumour DNA are increasingly investigated for PoC applications since they can be detected in various biological fluids associated with lung cancer. Nanocomposite materials, particularly GO/AuNP hybrids, provide synergistic advantages by combining the large surface area and abundant functional groups of GO for stable immobilization of biorecognition elements with the excellent conductivity and bioconjugation capability of AuNPs that enhance signal transduction. This review critically discusses key biomarker targets for lung cancer, the properties of GO and Au in biosensing, and the role of AuNP/GO nanocomposites in improving biosensor performance. It further examines the application of electrochemical biosensors for lung cancer biomarker detection, highlighting recent developments. Additionally, the review outlines current challenges limiting clinical translation and PoC implementation, provides recommendations to address these barriers, and discusses future perspectives for improving the detection of low-abundance biomarkers for early lung cancer diagnosis. Ultimately, these technologies seem promising for the development of rapid diagnostic tools equivalent to established platforms such as lateral-flow immunoassays. Full article

Surface-enhanced Raman scattering (SERS) offers a powerful route for biomolecular detection because it combines molecular specificity with high sensitivity, rapid optical readout, and multiplexing capability. In real biological samples, however, analytical performance is rarely determined by signal enhancement alone. Biofluids such as serum, plasma, saliva, urine, and interstitial fluid contain complex biomolecular mixtures that interfere with target capture, spectral response, and data interpretation. A practical SERS biosensor must therefore localize targets, stabilize spectral responses, tolerate matrix-induced variation, and convert complex spectra into reliable analytical information. This review discusses recent progress in SERS biosensing from an integrated system perspective, with particular focus on artificial intelligence/machine learning (AI/ML)-assisted interpretation. Direct label-free SERS provides chemically transparent readouts but is limited by stochastic adsorption, hotspot heterogeneity, and spectral variation in complex samples. Bio-recognition interfaces improve target localization, while signal-transduction strategies based on nanotags, immunoassays, clustered regularly interspaced short palindromic repeats (CRISPR) systems, nanozymes, and lateral-flow formats decouple molecular recognition from spectral generation. Digital SERS further improves measurement robustness by converting fluctuating intensities into countable, event-based outputs. AI/ML-assisted analysis can support full-spectrum classification, calibration transfer, explainability, and patient-level decision-making. We frame AI/ML-assisted SERS biosensing as an integrated architecture connecting substrate design, interface engineering, signal transduction, digital measurement, and clinical validation. Future progress will depend as much on validation-ready workflows as on plasmonic enhancement itself, especially for systems intended to operate across different samples, instruments, and clinical settings. Full article

Chemical contaminants in food pose a serious threat to public health, driving the need for sensitive, rapid, and on-site screening methods. Lateral flow immunoassay (LFIA) is rapid and portable but suffers from single-signal readout and insufficient label stability. Nanozymes, nanomaterials with enzyme-like catalytic activity and excellent stability, have emerged as promising signal labels to address these limitations. Moreover, their diverse physiochemical properties enable multiplex signal readout, where two or more complementary signals (e.g., colorimetric, fluorescent, chemiluminescent, photothermal, and surface-enhanced Raman scattering) are generated simultaneously from a single test line. This multiplex strategy significantly enhances detection sensitivity, accuracy, and reliability through signal amplification and self-calibration. This review provides a systematic overview of the catalytic properties and their major types used in multiplex signal LFIA. The signal combination strategies employed in nanozyme-based multiplex signal LFIA were also summarized, and their applications in detecting veterinary drugs, mycotoxins, pesticides, and other food chemical contaminants are highlighted. Ultimately, current challenges and future prospectives in this field are discussed. This review offers guidance for designing high-performance, nanozyme-based multiplex signal LFIA platforms for food safety monitoring. Full article

To improve clinical decision-making about Carbapenem-resistant Gram-negative bacteria (CR-GNB) infections and halt the spread of resistant microbes, quicker and less expensive diagnostic techniques are required. Thus, the purpose of this study was to thoroughly evaluate the diagnostic efficiency (sensitivity, specificity, and concordance) of direct-from-specimen multiplex lateral flow immunoassay (LFIA) across diverse raw clinical specimens and pathogen types from critically sick patients. A total of 300 non-duplicate samples were tested to detect CR-GNB. Five major Carbapenemase genes were detected directly from the specimen using carbapenem-resistant K.N.I.V.O. detection K-Set and from culture using culture-enhanced multiplex PCR. Turnaround time (TAT) of each method was calculated. The direct LFIA revealed 100% specificity for NDM, KPC, and IMP enzymes in all tested clinical matrices (blood, urine, and respiratory samples). The study demonstrated 100% sensitivity and specificity with perfect categorical agreement (κ = 1.000) for the blaKPC in the Klebsiella pneumoniae and for blaOXA-48 and blaIMP in the Acinetobacter baumannii; however, sensitivity of blaVIM was significantly diminished across all isolates and samples. TAT decreased significantly (p < 0.001) from 30 to 70 h to about 50 min. The tested direct LFIA facilitates the prompt enhancement of lifesaving tailored antibiotic treatment for severe illnesses. Full article

Background/Objectives: The global spread of carbapenemase-producing Gram-negative bacteria (CP-GNB) represents a major clinical challenge, causing severe hospital-acquired infections with limited treatment options. Accurate and rapid detection is essential for guiding antimicrobial therapy and implementing infection control measures. Lateral flow immunoassays (LFIAs) targeting the five main carbapenemase families are increasingly used in routine diagnostics, and many new commercial assays have recently become available, often without thorough assessment. The continuous evolution of these enzymes under antibiotic pressure requires regular reassessment of assay performance. Methods: In this study, we evaluated the Beright Carba-5 assay (Alltest Biotech, Hangzhou, China) targeting the five main carbapenemases (KPC, NDM, OXA-48-like, IMP, and VIM), on a panel of 77 whole-genome sequenced Gram-negative bacterial (GNB) isolates exhibiting reduced susceptibility to carbapenems. Seventy-three were carbapenemase-producing (CP) GNBs, including six VIM-, 18 OXA-48-, 14 KPC-, 9 NDM-, 8 IMP-, 10 multiple carbapenemase-, and eight non-targeted carbapenemase-producers. Results: The assay was rapid and easy to use, showing 100% (CI: 73.54% to 100%) specificity, with no false positive results. However, overall sensitivity of CP-GNB detection was lower than expected at 63.08% (CI: 50.20% to 74.72%), with numerous false negatives, particularly among IMP and NDM producers, and to a lesser extent, KPC producers. Detection was more reliable for VIM and OXA-48-like variants. Practical limitations, including insufficient buffer supply, reduced the number of tested isolates from the planned 100 to 77. Conclusions: Overall, the Beright assay demonstrated insufficient sensitivity for routine diagnostic use. Full article

The fabrication of SERS nanotags with efficient antibody loading and high signal enhancement remains a challenging task for combining surface-enhanced Raman spectroscopy (SERS) and lateral flow immunoassay (LFIA). In this study, bimetallic Au^DTNB@PDA^DTNB@Ag nanoparticles with a polydopamine (PDA)-based internal nanogap were synthesized and functionalized with anti-prolactin monoclonal antibodies to produce SERS nanotags. Here, polydopamine serves both as a spacer providing a nanogap between the core and the shell, and as a reaction layer to capture Raman reporter 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) within the nanogap. Regimes (conditions, protocols) for conjugating antibodies to Au^DTNB@PDA^DTNB@Ag were selected to preserve both the binding affinity for the target analyte and the Raman activity of the SERS nanotag. The SERS nanotag provides plasmonic absorption for visible colorimetric readout, as well as strong SERS signals for highly sensitive quantitative immunoassay. Measuring the Raman intensities of DTNB in the test zone after performing LFIA made it possible to determine prolactin with a detection limit of 0.2 ng/mL in the working range from 1 to 10 ng/mL. The achieved limit of detection was 10-fold lower than the LFIA coupled with colorimetric readout (4.7 ng/mL). The recoveries of prolactin from spiked serum samples were in the range of 70.2–82.6% with relative standard deviations of 2.3–6.8%. Overall, the Au^DTNB@PDA^DTNB@Ag nanotag demonstrated high stability, Raman activity, and specificity, indicating that the SERS nanotag with PDA-assisted internal nanogap is promising for use in SERS immunoassay of other target analytes. Full article

Decentralized diagnostics is undergoing a transformative shift from qualitative screening to high-precision quantification, driven by the clinical demand for rapid, point-of-care (POC) syndromic triage. Multiplexed lateral flow immunoassays (mLFIAs) serve as the foundational platform for this transition. However, their performance is limited by systemic factors such as fluidic lag, conjugate depletion, and spectral crosstalk. This review evaluates recent advances in engineered nanomaterials and artificial intelligence (AI)-driven detection as the dual pillars of next-generation multiplexing. The review covers different types of nanomaterial reporters—such as multicolor quantum dots, surface-enhanced Raman scattering nanotags, upconversion nanoparticles, surface-modified magnetic nanoparticles, and fluorescent nanodiamonds—that help address analytical challenges in lateral flow assays. We then discuss AI and machine learning methods, including convolutional neural networks, support vector machines, random forests, and transfer learning, that convert raw multi-channel signals into useful clinical data. Finally, we highlight the main challenges that still need to be addressed before these platforms can become WHO-ASSURED-compliant POC devices. The combination of engineered nanomaterial reporters and computational intelligence is transforming lateral flow assays into quantitative tools that can provide lab-quality clinical information at the POC. Full article

The COVID-19 pandemic highlighted the critical role of serological assays in understanding antiviral immune responses, monitoring vaccine efficacy, and informing public health strategies. This review provides a comprehensive overview of commonly used SARS-CoV-2 antibody detection methods, focusing on binding and neutralization assays. Antibody binding assays, including enzyme-linked immunosorbent assays (ELISAs), chemiluminescence immunoassays (CLIAs), lateral flow immunoassays (LFAs), and multiplex platforms, enable the rapid and high-throughput detection of immunoglobulin isotypes against various viral antigens. Neutralization assays, including live-virus, pseudovirus (PsV), and surrogate assays, offer functional insights into the ability of antibodies to prevent viral entry, though they often require higher biosafety levels and optimization. Serological assays, primarily antibody binding assays and several surrogate neutralization assays, received Emergency Use Authorization (EUA) during the pandemic, supporting seroprevalence efforts. Antibody binding assays and neutralization assays were also widely used in vaccine immunogenicity studies. Despite many standardization initiatives, assay standardization and data harmonization remain challenging and require further efforts. The choice of assay should be guided by study goals: antibody binding assays are preferred for high-throughput monitoring and epidemiological studies, while neutralization assays are essential for assessing functional immunity and variant-specific neutralization and protection. Full article

Chloramphenicol is a broad-spectrum antimicrobial agent whose use in food-producing animals is prohibited in many countries due to its association with severe adverse effects, including idiosyncratic aplastic anemia and genotoxicity. Despite these restrictions, chloramphenicol residues continue to be detected in food products, environmental compartments, and biological matrices, highlighting the need for reliable and sensitive analytical monitoring. This review provides a comprehensive overview of current analytical strategies for the detection of drugs in food and environmental samples, covering screening and confirmatory techniques, sample preparation approaches, and regulatory aspects. Rapid screening methods, such as enzyme-linked immunosorbent assays (ELISAs), lateral flow immunoassays (LFIAs), and biosensors based on antibodies, aptamers, and molecularly imprinted polymers, enable fast and cost-effective preliminary detection. Recent advances in nanomaterials and signal amplification strategies, including fluorescent reporters and surface-enhanced Raman scattering (SERS), have significantly improved sensitivity and assay performance. However, confirmatory methods based on liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) remain the reference standard due to their superior selectivity, sensitivity, and quantitative reliability. Attention is given to sample preparation workflows, including QuEChERS-based protocols and microextraction techniques, which enable efficient analysis of complex matrices. Finally, current regulatory frameworks and analytical challenges related to zero-tolerance policies are discussed, emphasizing the importance of robust and validated analytical methods for effective monitoring and food safety assurance. Full article

Background/Objectives: Melioidosis, caused by Burkholderia pseudomallei, is a severe tropical infectious disease associated with high mortality in endemic regions. Early diagnosis remains challenging because conventional diagnostic methods, including culture, serological assays, and molecular techniques, have limitations in sensitivity, specificity, processing time, and accessibility in resource-limited settings. This review evaluates current diagnostic approaches and highlights the potential of short peptide biomarkers for improving melioidosis detection. Methods: A narrative literature review was conducted using four electronic databases (PubMed, Scopus, Web of Science, and Google Scholar) covering publications from 2000 to 2024. Relevant studies were identified using predefined keywords related to melioidosis diagnostics, biomarkers, and peptide-based approaches, and were screened based on relevance to diagnostic methods and peptide biomarker development in Burkholderia pseudomallei. Results: Several biomarkers have been investigated for melioidosis diagnostics, including capsular polysaccharide (CPS), type III secretion system 1 (TTS1), and other virulence-associated proteins such as Hcp1 and BPSS1187. Among these, CPS and TTS1 are highly conserved and specific targets widely used in molecular and antigen-based detection methods. Short peptide epitopes derived from these antigens demonstrate promising advantages over whole proteins, including improved stability, high specificity, easier synthesis, and reduced production costs. Advances in epitope prediction technologies and peptide-based biosensors have further expanded the potential applications of short peptides in rapid diagnostic platforms, including ELISA, lateral flow immunoassays, and biosensor-based detection systems. Conclusions: Short peptide–based biomarkers represent a promising strategy for developing rapid, sensitive, and cost-effective diagnostic tools for melioidosis, particularly in endemic and resource-limited settings. Full article

Pesticide residues in food and agricultural products continue to constitute a significant concern for food safety, particularly when rapid decision-making is required across production and supply chains. Although chromatographic methods such as GC-MS and LC-MS/MS remain essential for confirmatory analysis, their dependence on central laboratories limits their applicability for field screening. Consequently, portable biosensor-based detection platforms have attracted increasing attention as rapid screening tools. This review synthesizes 26 peer-reviewed studies published between 2010 and 2025 on portable biosensor-based screening tools for pesticide detection in food and agricultural matrices, including electrochemical sensors, immunoassays, aptamer-based systems, paper-based lateral flow devices, and smartphone-assisted platforms. Given the heterogeneity of analytes, sensing mechanisms, and study designs, a narrative synthesis approach was applied. Overall, the evidence suggests a shift from laboratory-centered detection toward field-deployable technologies that may support preliminary screening within food safety monitoring frameworks. Paper-based lateral flow assays are widely reported as deployable formats, while electrochemical and affinity-based platforms are often positioned as intermediate solutions for mobile or semi-controlled testing environments. However, most platforms remain at the proof-of-concept or early validation stage, and challenges related to matrix interference, long-term stability, reproducibility, standardization, and large-scale implementation persist. This review highlights the potential role of portable biosensor technologies as complementary tools within tiered food safety monitoring systems and outlines key priorities for further development before wider regulatory integration can be considered. Full article

Antibiotic residues in aquatic products pose a serious food safety concern, whereas conventional laboratory methods often fail to meet the demand for on-site rapid screening. This study systematically reviews the research progress from 2021 to 2025 on both the risks of antibiotic residues in aquatic products and the development of rapid on-site detection technologies. First, based on a literature survey covering major aquatic products (e.g., fish, shrimp, and shellfish), the widespread occurrence of multiple antibiotics at high concentrations was documented, with quinolones and sulfonamides identified as the most frequently detected classes. To address the need for on-site testing, this review focuses on six rapid detection techniques: fluorescent sensor (FRS), lateral flow immunoassay (LFIA), surface-enhanced Raman scattering (SERS), enzyme-linked immunosorbent assay (ELISA), electrochemical sensor (ECRS), and colorimetric sensor (CRS). The core principles, technical advantages, recent application cases (e.g., integration with smartphones and novel nanomaterials), and development trends for each method are analyzed. Finally, it discusses the current challenges faced by existing on-site detection approaches and their potential solutions. Technology selection strategies tailored to different application scenarios (e.g., aquaculture farms, distribution channels, and consumer-level use) are also proposed. Full article

Novel, accurate molecular diagnostics are driving new advances across medicine, public health, and environmental monitoring. Surface-enhanced Raman spectroscopy (SERS) nanotags are powerful platforms for ultrasensitive, multiplexed, and quantitative detection of molecular targets. This review focuses on indirect sensing strategies, where SERS nanotags act as signal transducers, resulting in enhanced and unique Raman spectra upon binding of target analytes (high specificity) and allowing for ultralow limits of detection. These indirect SERS sensors typically consist of a plasmonic core, a Raman reporter molecule, and a ligand that targets the analyte of interest. Each of these components contributes to the sensitivity, stability, and selectivity of the system. Rational design of SERS nanotags requires balancing enhancement efficiency with reproducibility, biocompatibility, and assay integration. The choice of reporter molecules, for instance, governs spectral uniqueness and enables multiplexed detection of multiple analytes within a single sample. Recent advances in artificial intelligence and machine learning are accelerating nanotag development by enabling predictive control over nanostructure geometry, composition, and optical response. SERS nanotags are increasingly being integrated into diagnostic formats, such as lateral flow assays and microfluidic devices, offering both qualitative and quantitative analysis at the point of care. This review provides an overview of key design principles, common strategies for nanostructure functionalization and stabilization, and emerging biosensing applications, serving as a practical guide for researchers seeking to design and implement SERS nanotags. Full article