Pretreatment steps of current rapid detection methods for mycotoxins in edible oils not only restrict detection efficiency, but also produce organic waste liquid to pollute environment. In this work, ...a pretreatment-free and eco-friendly rapid detection method for edible oil is established. This proposed method does not require pretreatment operation, and automated quantitative detection could be achieved by directly adding oil samples. According to polarity of target molecules, the content of surfactant in reaction solutions could be adjusted to achieve the quantitative detection of AFB1 in peanut oil and ZEN in corn oil. The recoveries are between 96.5%–110.7% with standard deviation <10.4%, and the limit of detection is 0.17 μg/kg for AFB1 and 4.91 μg/kg for ZEN. This method realizes full automation of the whole chain detection, i.e. sample in-result out, and is suitable for the on-site detection of batches of edible oils samples.
•Chemiluminescence immunoassay was integrated with magnetic beads separation.•A pretreatment-free and eco-friendly rapid detection method was established.•The detection of mycotoxins in edible oils realized the full automation in whole chain.•The mode of sample in-result out was suitable for on-site detection of batches of samples.
Chemiluminescence immunoassay (CLIA) has been greatly developed in the past several decades due to its good sensitivity and specificity. Nowadays, CLIA has been highly improved with novel ...nanomaterials and newly-developed technologies. The advancement of CLIA combined with relevant technologies are reviewed in the paper, including enhanced chemiluminescent, antibody preparation, aptamer selection, nanomaterials assisted CLIA, and CLIA coupling with newly-developed technologies. Finally, some critical challenges are discussed in the field and the future development direction of CLIA is prospected. The review will be of great significance for CLIA basic research and practical applications in the fields of biomedical diagnostics, food and drug testing, environmental monitoring, and other fields.
•Enhanced chemiluminescence system based on phenolic compounds, metal nanoparticles, and other nanomaterials.•The preparation of antibody fragments and multi-functional antibody for immune reaction.•Aptamer selection and its replacing antibody in immune reaction.•The application of magnetic particles in CLIA as solid-phases carriers and separation tool.•CLIA combined with novel technologies for exploring various detection platforms.
Chemiluminescence immunoassay (CLIA) has always been a great challenge in detecting cardiac troponin I (cTnI) in whole blood samples without centrifugation because of the interference of red blood ...cells and low sensitivity. In this study, the antigens and erythrocytes in the blood were captured by the antibodies immobilized on the magnetic particles, recognized by another biotin-conjugated cTnI antibody and detected by streptavidin/acridine aster-conjugated polychloromethylstyrene microspheres (PCMS). After magnetic separation, the supernatant was transferred and measured. No significant difference was noted between the cTnI concentrations of the serum samples, plasma samples and whole blood. The prepared PCMS provided more functional areas to conjugate streptavidin and acridinium ester, so the immunoassay has highly sensitive, the limits of blank at 0.012 ng/mL, and functional sensitivity at 0.019 ng/mL with a CV of 20%, and 0.058 ng/mL with a CV of 10%. Total precision of any sample type ranged from 2.62%~5.67%. The assay was linear over the studied range of 0.01–50.00 ng/mL, and no hook effect was found when cTnI concentrations reached 1900 ng/mL. No significant interference was noted with the potential endogenous interfering substances. Compared with the commercial kit (Abbott assay kit), the correlation coefficient was 0.9859. A washing-free CLIA was established for the rapid detection of cTnI in human whole blood, using erythrocyte capture antibodies-conjugated magnetic nanoparticles for eliminating the influence of erythrocytes and PCMS for signal amplification, which showed great potential in clinical application.
A washing-free and rapid sandwich-type chemiluminescence immunoassay (CLIA) based on cTnI/erythrocyte antibodies-conjugated magnetic nanoparticles and streptavidin/acridine aster-conjugated PCMS was developed for the clinical determination of cardiac troponin I (cTnI) in human whole blood. Display omitted
Abstract
Background
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel β-coronavirus, causes severe pneumonia and has spread throughout the globe rapidly. The disease associated ...with SARS-CoV-2 infection is named coronavirus disease 2019 (COVID-19). To date, real-time reverse-transcription polymerase chain reaction (RT-PCR) is the only test able to confirm this infection. However, the accuracy of RT-PCR depends on several factors; variations in these factors might significantly lower the sensitivity of detection.
Methods
In this study, we developed a peptide-based luminescent immunoassay that detected immunoglobulin (Ig)G and IgM. The assay cutoff value was determined by evaluating the sera from healthy and infected patients for pathogens other than SARS-CoV-2.
Results
To evaluate assay performance, we detected IgG and IgM in the sera from confirmed patients. The positive rate of IgG and IgM was 71.4% and 57.2%, respectively.
Conclusions
Therefore, combining our immunoassay with real-time RT-PCR might enhance the diagnostic accuracy of COVID-19.
A peptide-based magnetic chemiluminescence enzyme immunoassay for the detection of SARS-CoV-2 antibodies was developed; 71.4% (197 of 276) and 57.2% (158 of 276) of the COVID-19 inpatients were positive for IgG and IgM against SARS-CoV-2.
Display omitted
•A photoaffinity labeled probe for tetracycline drugs (TCs) is first synthesized.•A natural TetR protein is first captured from TC-resistant bacteria by the probe.•The TetR recognize ...10 TCs that shows better performance that the previous TetR.•A chemiluminescence method is developed on microplate to detect TCs in milk.
In this study, a photoaffinity labeled activity-based protein profiling probe for tetracycline drugs was first synthesized that was used to capture a type of natural TetR protein from Escherichia coli. The TetR simultaneously recognized 10 tetracycline drugs. Then it was used as recognition reagent to develop a direct competitive chemiluminescence immunoassay for detection of the 10 drugs in milk. The IC50 values for these drugs were in the range of 0.084–0.32 ng/mL, and the limits of detection were in the range of 2.0–9.0 pg/mL. Their recoveries from the standards fortified blank milk samples were in the range of 68.4%-91.3%. After comparison, the natural TetR protein and the developed method showed better performances than the previous TetR proteins and the related immunoassays. Therefore, this method could be used as a practical tool for routine screening the residues of tetracycline drugs in milk. Furthermore, this type of probe could also be used to produce the receptors and develop different immunoassays for other classes of drugs.
Abstract
Objectives
To examine and summarize the current literature on serologic methods for the detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Methods
A ...literature review was performed using searches in databases including PubMed, medRxiv, and bioRxiv. Thirty-two peer-reviewed papers and 23 preprints were examined.
Results
The studies included lateral flow immunoassay, enzyme-linked immunosorbent assay, chemiluminescence immunoassay, and neutralizing antibody assays. The use of all major SARS-CoV-2 antigens was demonstrated to have diagnostic value. Assays measuring total antibody reactivity had the highest sensitivity. In addition, all the methods provided opportunities to characterize the humoral immune response by isotype. The combined use of IgM and IgG detection resulted in a higher sensitivity than that observed when detecting either isotype alone. Although IgA was rarely studied, it was also demonstrated to be a sensitive marker of infection, and levels correlated with disease severity and neutralizing activity.
Conclusions
The use of serologic testing, in conjunction with reverse transcription polymerase chain reaction testing, was demonstrated to significantly increase the sensitivity of detection of patients infected with SARS-CoV-2. There was conflicting evidence regarding whether antibody titers correlated with clinical severity. However, preliminary investigations indicated some immunoassays may be a surrogate for the prediction of neutralizing antibody titers and the selection of recovered patients for convalescent serum donation.
A novel chemiluminescence (CL) immunosensor array in combination with a dual-signal amplification strategy was developed for rapid and ultrasensitive detection of multiple mycotoxins in herbal ...medicine. The multi-component immunosensor array was constructed by immobilizing different bovine serum albumin combined mycotoxins on the corresponding sites of the aldehyde-modified glass slide. After competitive immunoreactions, CL triggered by signal tags captured on all the sensing sites can be collected by a charge-coupled device simultaneously for joint detection of several mycotoxins. By assembling a high ratio of horseradish peroxidase (HRP) and IgG on the surface of gold nanoparticles (AuNPs), a biofunctionalized complex named HRP@AuNP-IgG was prepared and served as the primary signal tag to amplify the CL signals. Then, by introducing tyramine signal amplification (TSA) technique, a new round of HRP could deposit around the HRP@AuNP-IgG, which brought the secondary CL amplification. As a proof of concept, the CL imaging sensor array was applied to the trace detection of citrinin, aflatoxin B1 and ochratoxins A in red yeast rice samples. Under optimal conditions, it exhibited wide linear ranges over 4 orders of magnitude and much lower limits of detection than previous works. Owing to the excellent sensitivity (50–57-fold signal amplification and detection limits down to sub-pM level), acceptable throughput (20 tests h−1), small amounts of reagents (3.5 μL for each test), simple sample pretreatment (no necessary of separation for 3 mycotoxins), high selectivity, acceptable stability and accuracy, the proposed sensing platform showed broad prospects in the joint monitoring of low-abundant mycotoxins and safety evaluation of herbal medicines.
Display omitted
•An ultrasensitive and multiplex platform was set up for mycotoxins sensing.•A multi-component immunosensor was coupled with dual chemiluminescence amplification.•The work showed detection limits down to sub-pM level and a throughput of 20 tests/h.•Joint detection of trace mycotoxins in real samples can be achieved conveniently.•The protocol exhibited prospects in safety evaluation of herbal medicine.
Single atom nanozymes (SAzymes) are considered as the most hopeful candidates for replacing natural enzymes. In this work, a flow-injection chemiluminescent immunoassay (FI-CLIA) based on a ...Fenton-like activity single atom cobalt nanozyme (Co SAzyme) was developed for the rapid and sensitive detection of 5-fluorouracil (5-Fu) in serum for the first time. Co SAzyme was prepared by an in-situ etching method at room temperature using ZIF-8 metal-organic frameworks (ZIF-8 MOFs). With excellent chemical stability and ultra-high porosity of ZIF-8 MOFs as the core, Co SAzyme presents high Fenton-like activity which can catalyze the decomposition of H2O2 to produce large amounts of superoxide radical anions, thus effectively amplifying the chemiluminescence of the Luminol-H2O2 system. In addition, carboxyl-modified resin beads were used as the substrate to load more antigens due to its advantages of good biocompatibility and large specific surface area. Under optimal conditions, the detection range of 5-Fu was 0.001–1000 ng mL−1 with a limit of detection of 0.29 pg mL−1 (S/N = 3). Furthermore, the immunosensor was successfully applied for the detection of 5-Fu in human serum samples with satisfactory results, displaying the potential application of this strategy for bioanalysis and clinical diagnosis.
A competitive CL immunoassay based on Fenton-like effect was proposed for the first time. The immunosensor for the ultra-sensitive detection of 5-Fu in human serum was constructed using Co SAzyme as a Fenton-like probe and carboxyl-modified resin beads as the substrates. Display omitted
•A novel FI-CLIA based on carboxyl resin beads and Co SAzyme catalytic amplification is proposed.•Co SAzyme with outstanding catalytic properties was synthesized by an in situ etching strategy at room temperature.•Carboxyl resin beads with good biocompatibility were served as carrier for loading more coating antigens.•The immunosensor provides an economical, sensitive and specific method for 5-Fu detection.
•Moulds, produce various secondary metabolites like mycotoxins.•Mycotoxin co-contamination in food and feed is widely reported.•Immunoassays methods are extensively used with several advantages.•The ...Evidence Investigator Biochip Array Technology is based on a biochip.•The Evidence Investigator Myco 7 is used for the detection of mycotoxins.
Cereal grains are widely cultivated agricultural commodities, and they constitute a key source of energy. However, many of them are affected by fungal contamination, and consequently, by the presence of mycotoxin. The development of monitoring techniques to evaluate exposure, is therefore of interest. Immunoassays have recently emerged as potential alternatives for the study of mycotoxins. This study focuses on a validation of a biochip array technology (BAT) for multi-mycotoxins screening in oat, barley, rye, and wheat grains. The Evidence Investigator Myco 7 (RANDOX Food Diagnostic), based in a competitive chemiluminescent immunoassay, was used for the simultaneous semi-quantitative detection of the mycotoxin's immunoassays. According to validation results, spiked rice samples showed low false results (5 % of false negatives and 5 % of false positives for fumonisins, 5 % of false negatives for Zearalenone, Aflatoxin B1, T2HT2 and Deoxynivalenol and 5 % of false positives were found for ochratoxin A). In the spiked samples of other cereals, were found 5 % of false positives for fumonisin B1+fumonisin B2, zearalenone, ochratoxin A and aflatoxin B1 and 5 % of false negatives were found for Fumonisin 1 + Fumonisin 2, Ochratoxin A, Aflatoxin B1 and T2+HT2 in agreement with European Union legislation performance criteria. This BAT immunoassay provides important benefits for the rapid and efficient screening of several mycotoxins in cereal grain samples at various levels.
Display omitted
•The bienzymatic catalysis strategy increases sensitivity and detection range.•4-bromophenol induced strong and persistent CL of the luminol reaction.•The BCSI assay allows intuitive ...analysis and can be easily applied.
The 10-kDa chemokine interferon-gamma-inducible protein 10 (IP-10) is considered one of the most promising biomarkers for diagnosing both tuberculosis and COVID-19 infections. The blood samples of patients at different disease states contain different levels of IP-10, which need to be detected in a rapid, specific and ultrasensitive manner. Here, we report a bienzymatic chemiluminescence sandwich immunoassay (BCSI) assay for the ultrasensitive and stable detection of IP-10. In this assay, IP-10 is first efficiently captured using a double-antibody sandwich strategy. The detection antibody is linked to catalase (CAT) via a streptavidin–biotin signal amplification system to achieve highly efficient conversion of hydrogen peroxide (H2O2) to oxygen and water. In the chemiluminescence (CL) reaction, horseradish peroxidase (HRP) acts as an efficient catalyst, and 4-bromophenol acts as an enhancer for the cyclic transition of HRP, which results in a strong and durable CL signal. The bienzymatic catalysis with CAT and HRP and the potentiation of 4-bromophenol enables the assay to be ultrasensitive and stable. The CL intensity was found to be well correlated with the detection of IP-10 at levels in the range of 0.71 to 125,000 pg/mL, which covers more than 6 orders of magnitude, with a detection limit of 0.63 pg/mL. The coefficient of variation was 1.49%, and the recovery range of IP-10 in serum was 86.21%-104.57%. This assay provides a wide linear range and high sensitivity and may be a promising method for the high-throughput detection of IP-10 in the diagnosis of tuberculosis and COVID-19.
PDF
