Objective To evaluate the performance of a new fluorescence immunochromatographic assay for interleukin-6 (IL-6) detection. Methods A total of 104 serum samples from patients with suspected ...infections and normal population were collected at Peking Union Medical College Hospital in December, 2021. Assay A (Wanfu biofluorescence immunochromatography assay) and B (Siemens chemiluminescence assay) were used as references to evaluate the equivalence of the Innova assay for detecting serum IL-6. Meanwhile, 39 homologous paired plasma and serum were collected to evaluate the consistency of the Innova assay in detecting IL-6 content in different types of samples. Results In quantitative analysis, two samples were excluded because the content was above the limit of detection for method B. Compared with the assay A or B, the regression equations of the Innova assay were Y=-7.0950+1.1924X (R2=0.9448), Y=-2.6143+1.3072X (R2=0.9391), and the Pearson correlation coefficients were 0.9720 and 0.9691, respectively. With
•We have developed a double-antibody sandwich-based chemiluminescent immunoassay to determine the plasma concentration of S100A1.•S100A1 is a sensitive and specific cardiac biomarker for early ...diagnosis of acute myocardial infarction.•S100A1 may provide prognostic information for acute myocardial infarction after PCI.
A member of the S100 family of Ca2+-binding proteins, S100A1 is highly expressed in cardiac muscle tissue. Although this protein is considered an indicator of acute myocardial infarction (AMI), high-throughput and sensitive detection methods are still urgently needed. We constructed a rapid and sensitive method for detecting S100A1 and to investigate the clinical utility of S100A1 as a biomarker for the early diagnosis of AMI and subsequent prognostic assessments. We developed an automated chemiluminescent immunoassay to detect S100A1. We then analyzed the performance of the newly developed assay including evaluation of the analytical sensitivity, analytical selectivity, linear range, accuracy and repeatability.
We recruited 87 patients with AMI or angina pectoris to explore the value of this marker for the early diagnosis and prognostic assessment.
The chemiluminescent-immune-based S100A1 assay had functional analytical sensitivity with a detection limit of 0.13 ng/ml, and a wide linear range of 0.13–31.66 ng/ml. It also exhibited good repeatability with intra-assay and inter-assay findings of <5% and <15%, respectively. Plasma S100A1 was found to have a higher diagnostic sensitivity than conventional cardiac biomarkers (creatine kinase-MB and cardiac troponin T). The survival analysis showed that a higher concentration of plasma S100A1 (>1.02 ng/ml) was notably associated with the poor prognosis of AMI patients after first PCI.
Measurement of circulating S100A1 concentrations with our newly developed chemiluminescent-immune-based assay shows potential for use in the clinic. This assay could enable early identification and prognostic assessment of AMI.
Rapid and on-site detection of chloramphenicol (CAP) is of great significance for food safety. Herein, we established an affordable and portable homogeneous fiber optic chemiluminescent immunosensor ...(hoFOCI) by streamlining the immunoassay and integrating the detection platform. By immobilizing the artificial antigens of CAP and the luminescent functional groups onto the fiber optic, the biorecognition and signal conversion could be performed without any washing steps, which greatly reduced the time consumption and simplified the operation. For chemiluminescence signal detection, a low-cost and integrated detection platform was constructed, which was designed to be compatible with fiber optic probe. The hoFOCI had a good linear response to CAP in the concentration of 10–106 pg/mL, with a detection limit of 2.95 pg/mL. The feasibility was also validated by assaying CAP in real honey samples, and a high accuracy and reproducibility were obtained. Therefore, the proposed hoFOCI is expected to be appropriate for rapid and on-site detection of CAP in food stuffs.
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•A novel hoFOCI for rapid and on-site detection of chloramphenicol was developed.•Homogeneous assay offered a simple analysis procedure without washing steps.•Integrated hoFOCI device was low-cost and field operable.•High sensitivity, accuracy and stability were obtained for chloramphenicol analysis.
Vitamin D has received significant attention from clinical societies, researchers, and the general population in recent years. While 25-hydroxyvitamin D (25(OH)D) is the most commonly-used biomarker ...of vitamin D status, 1α,25-dihydroxyvitamin D (1,25(OH)
2
D), its bioactive form, plays a critical role in regulating calcium and phosphorus homeostasis and is also involved in the immune system and cellular differentiation. Consequently, accurate measurements of 1,25(OH)
2
D can aid in the differential diagnosis of calcium-related disorders such as hypocalcemia in vitamin D-dependent rickets and hypercalcemia due to inappropriate increase of serum 1,25(OH)
2
D in granulomatous diseases. However, due to its lipophilicity and very low circulating concentration, the measurement of 1,25(OH)
2
D is particularly challenging. Over the past several decades, numerous efforts have been made to develop sensitive, specific, and practical laboratory methods for measuring 1,25(OH)
2
D. Methods using radioreceptor assay, radioimmunoassay, enzyme immunoassay, enzyme-linked immunosorbent assay, automated chemiluminescent immunoassay, and liquid chromatography-tandem mass spectrometry have been described. Each of these methods has unique advantages and limitations, and some are no longer used. Despite the sophisticated methods in use today, substantial variations between methods still exist. A concerted effort toward standardization of 1,25(OH)
2
D measurement is needed to ensure accurate and reliable results across laboratories and methods.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a causal agent of Coronavirus Disease 2019 (COVID-19) has led to the global pandemic. Though the real-time reverse transcription ...polymerase chain reaction (RT-PCR) acting as a gold-standard method has been widely used for COVID-19 diagnostics, it can hardly support rapid on-site applications or monitor the stage of disease development as well as to identify the infection and immune status of rehabilitation patients. To suit rapid on-site COVID-19 diagnostics under various application scenarios with an all-in-one device and simple detection reagents, we propose a high-throughput multimodal immunoassay platform with fluorescent, colorimetric, and chemiluminescent immunoassays on the same portable device and a multimodal reporter probe using quantum dot (QD) microspheres modified with horseradish peroxidase (HRP) coupled with goat anti-human IgG. The recombinant nucleocapsid protein fixed on a 96-well plate works as the capture probe. In the condition with the target under detection, both reporter and capture probes can be bound by such target. When illuminated by excitation light, fluorescence signals from QD microspheres can be collected for target quantification often at a fast speed. Additionally, when pursuing simple detection without using any sensing devices, HRP-catalyzed TMB colorimetric immunoassay is employed; and when pursuing highly sensitive detection, HRP-catalyzed luminol chemiluminescent immunoassay is established. Verified by the anti-SARS-CoV-2 N humanized antibody, the sensitivities of colorimetric, fluorescent, and chemiluminescent immunoassays are respectively 20, 80, and 640 times more sensitive than that of the lateral flow colloidal gold immunoassay strip. Additionally, such a platform can simultaneously detect multiple samples at the same time thus supporting high-throughput sensing; and all these detecting operations can be implemented on-site within 50 min relying on field-operable processing and field-portable devices. Such a high-throughput multimodal immunoassay platform can provide a new all-in-one solution for rapid on-site diagnostics of COVID-19 for different detecting purposes.
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•We propose a multimodal immunoassay platform for multi-purpose COVID-19 diagnostics.•Fluorescent high-throughput immunoassay can be used for common screening.•Chemiluminescent one has improved sensitivity, and colorimetric one is rather simple.•A multimodal immunoassay sensing system (MISS) is designed for automatic sensing.•On-site diagnostics can be done in 50 min with high accuracy and good selectivity.
Co single‐atom catalysts (SACs) with good aqueous solubility and abundant labelling functional groups were prepared in Co/Fe bimetallic metal‐organic frameworks by a facile solvothermal method ...without high‐temperature calcination. In contrast to traditional chemiluminescence (CL) catalysts, Co SACs accelerated decomposition of H2O2 to produce a large amount of singlet oxygen (1O2) rather than superoxide (O2.−) and hydroxyl radical (OH.). They were found to dramatically enhance the CL emission of the luminol‐H2O2 reaction by 1349 times, and, therefore, were employed as very sensitive signal probes for conducting CL immunoassay of cardiac troponin I. The detection limit of the target analyte was as low as 3.3 pg mL−1. It is the first time that employment of SACs for boosting CL reactions has been validated. The Co SACs can also be employed to trace other biorecognition events with high sensitivity.
Illuminate your chemistry! Co single‐atom catalysts with Fenton‐like catalytic activity were prepared on bimetallic metal–organic frameworks. They were found to greatly enhance luminol CL emission by accelerating decomposition of H2O2 to produce a large amount of singlet oxygen. They can act as sensitive chemiluminescent probes for tracing biorecognition events such as immune binding (see figure).
•Chemiluminescent immunoassay can replace microneutralization test for testing severe acute respiratory syndrome coronavirus-2 neutralizing antibodies.•Mathematical models can evaluate the ...effectiveness, protectiveness and durability of vaccines.•Only 5.35% of vaccinees had protective capability of NAb following the second dose of vaccine.•People should receive a third dose of vaccine, and the vaccine should be administered once every 6 months.
A specific and sensitive automated chemiluminescent immunoassay (CLIA) was developed to detect neutralizing antibody (NAb) levels. This assay can be used for the diagnosis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, treatment and vaccine evaluation.
The SARS-CoV-2 receptor-binding domain (RBD) and a stabilized version of the spike ectodomain as antigens were detected by CLIA. Sera NAb titers and concentrations from 860 SARS-CoV-2 vaccinees, 232 SARS-CoV-2 convalescent patients and 675 healthy individuals were tested by microneutralization test (MNT) and CLIA, respectively. Mathematical models were established to evaluate the relationship between two variables in different groups.
With the RBD-based CLIA protocol, CLIA can be used to replace MNT to test SARS-CoV-2 NAb. Vaccine effectiveness, protectiveness and durability can be evaluated effectively by mathematical models. It is
Analysing the relationship between NAb titers and concentrations, R2 for the decision-making tree was 0.870 and that of progressive linear fitting was 0.821. The receiver operating characteristic curve indicated specificity of 78.1%, sensitivity of 87.4%, cut-off value of 6.43 AU/mL and borderline range of 5.79–7.07 AU/mL for CLIA. Three-quarters (75.4%) of vaccinees were found to be NAb positive, and 5.35% vaccinees had NAb protective capability. The half-life of NAb in vaccinees was 10–11 weeks.for vaccinees to take a NAb assay periodically.
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Levels of neutralizing antibodies (NAb) after vaccine against coronavirus disease 2019 (COVID-19) can be detected using a variety of methods. A critical challenge is how to apply simple and accurate ...methods to assess vaccine effect. In a population inoculated with three doses of the inactivated Sinopharm/BBIBP vaccine, we assessed the performance of chemiluminescent immunoassay (CLIA) in its implementation to detect severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) specific antibodies, as well as the antibody kinetics of healthcare workers throughout the course of vaccination. The antibody levels of NAb, the receptor-binding-domain (RBD) antibodies and IgG peaked one month after the second and remained at a relatively high level for over three months after the booster injection, while IgM and IgA levels remained consistently low throughout the course of vaccination. The production of high-level neutralizing antibodies is more likely when the inoculation interval between the first two doses is within the range of one to two months, and that between the first and booster dose is within 230 days. CLIA showed excellent consistency and correlation between NAb, RBD, and IgG antibodies with the cytopathic effect (CPE) conventional virus neutralization test (VNT). Receiver operating characteristic (ROC) analysis revealed that the optimal cut-off levels of NAb, RBD and IgG were 61.77 AU/ml, 37.86 AU/ml and 4.64 AU/ml, with sensitivity of 0.833, 0.796 and 0.944, and specificity of 0.768, 0.750 and 0.625, respectively, which can be utilized as reliable indicators of COVID-19 vaccination immunity detection.
The levels of serum M. pneumoniae typing antibodies in children with community-acquired pneumonia (CAP) were detected by chemiluminescent immunoassay (CLIA) to explore the clinical role of M. ...pneumoniae typing antibody (MP-IgM, MP-IgG) in M. pneumoniae pneumonia.
A total of 387 Child patients with CAP diagnosed at the Pediatric outpatient department of Zengcheng Branch, Nanfang Hospital, Southern Medical University, were enrolled between January 2020 to December 2021 and divided into M. pneumoniae pneumonia (MPP) group (n = 210) and non-M. pneumoniae pneumonia (NMPP) group (n = 177). Firstly, Clinical data, full blood count (WBC, NEU%, LYM%, MONO%, EOS%, BASO%, RBC, HGB, PLT) and biochemical tests (AST, LDH, ɑ-HBDH, CK, CKMB, CRP, PCT, IL-6) as well as laboratory diagnostic tests (MP-IgM, MP-IgG) were compared between the two groups. Secondly, we assessed the correlation between the average level of M. pneumoniae typing antibody detected by CLIA and the titer of anti-M. pneumoniae antibody (MP-Ab) tested by passive agglutination (PA) method. Thirdly, receiver operating characteristic (ROC) curve for the MP-IgM and MP-IgG was examined to evaluate the value of diagnosing M. pneumoniae pneumonia. Finally, we follow-up 120 cases of MPP group and analysis medication results.
(1) Mean age, runny nose, expectoration, LYM%, NEU%, HGB, AST, MP-IgM and MP-IgG were statistically significant in the MPP group and NMPP group (all P < 0.05). (2) Correlation analysis showed that MP-IgM average level was linearly associated with MP-Ab titer (R2 = 0.84) and MP-IgG average level was exponentially correlated with MP-Ab titer under 1:640 (R2 = 0.96). (3) The ROC curve of MP-IgM and MP-IgG were significantly different (both P < 0.001). A serum MP-IgM level above 1 S/CO and MP-IgG level above 14.15 AU/mL were significant predictors for M. pneumoniae pneumonia: area under the curve (AUC) of 0.810, 0.815; standard error (SE) of 0.021, 0.022; 95 % confidence interval (CI) of 0.768–0.852, 0.773–0.858; the diagnostic sensitivity of 74.3 %, 62.1 %; and specificity of 72.9 %, 87.0 %; respectively. (4) Of the 120 children with M. pneumoniae pneumonia followed up, 79 (65.8 %) cases took azithromycin and 68 (86.1 %) cases were recovered.
A series of our studies shown that, CLIA, speedy and automated clinical examination method, has higher specificity and sensitivity for the quantitative detection of MP-IgM and MP-IgG, playing an important role of early diagnosis as well as prompt intervention to reduces macrolide-resistant strains and sequelae of children with M. pneumoniae pneumonia.
Considering processing concerns regarding emerging food safety incidents and large-scale food testing, efficient and straightforward screening tools are urgently needed. The requirements for this ...technology include effective sample pretreatment, sensitive assay, and sample-to-answer solution that enable the detection of trace amounts of contaminants in complex food matrices. Here, we developed a chemiluminescence- and optical fiber-based fully automated immunosensing (COFFAI) system that conducts chemical contaminant food screening in a truly “sample-to-result” manner. Instead of utilizing laborious benchtop sample purification techniques followed by a time-consuming manual ELISA procedure, the user simply injects the sample of interest, and the whole procedure is automatically processed. We demonstrated that the utility of our COFFAI system can be used to detect trace amounts of chemical contamination in various milk samples within approximately 75 min. This method showed an ultrahigh sensitivity with a quinolone detection limit in the 0.022–0.065 µg/L range for skim milk, whole milk, and raw milk samples. The integration of pretreatment and assay into one automated system is an effective method for food testing. We believe that this platform provides a general method for efficient contaminant screening in foodstuffs.
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•We designed a fully automated system that enables “sample-to-result” contaminant screening.•A novel immunoaffinity-based sample pretreatment method that does not require the use of an organic solvent was designed.•An optical fiber and charge-coupled device sensor was used for highly sensitive quantification.
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