Sensitive Chemiluminescent Immunoassay Research Articles

Prognostic and therapeutic monitoring value of plasma and urinary cytokine profile in primary membranous nephropathy: the STARMEN trial cohort

Abstract Background and hypothesis Primary membranous nephropathy (PMN) is usually caused by anti-PLA2R autoantibodies. There are different therapeutic options according to baseline risk. Novel biomarkers are needed to optimize risk stratification, and predict and monitor the response to therapy, as proteinuria responses may be delayed. We hypothesized that plasma or urinary cytokines may provide insight into the course and response to therapy in PMN. Methods Overall, 192 data-points from 34 participants in the STARMEN trial, randomized to tacrolimus-rituximab (TAC-RTX) or corticosteroids-cyclophosphamide (GC-CYC), were analyzed for plasma and urine cytokines using a highly sensitive chemiluminescence immunoassay providing a high-throughput multiplex analysis. Results Baseline (pretreatment) urinary CXCL13 predicted the therapeutic response to TAC-RTX. Cytokine levels evolved over the course of therapy. The levels of nine plasma and six urinary cytokines correlated with analytical parameters of kidney damage and disease activity, such as proteinuria, eGFR and circulating anti-PLA2R levels. The correlation with these parameters was most consistent for plasma and urinary GDF15, plasma TNF-α and urinary TWEAK. Decreasing plasma GDF15 levels were associated to response to GC-CYC. Four clusters of cytokines were associated to different stages of response to therapy in the full cohort, with the less inflammatory cluster associated to remission. Conclusion In conclusion, PMN displayed characteristic plasma and urine cytokine patterns that evolved over time as patients responded to therapy. Baseline urinary CXCL13 concentration could be a prognostic marker of response to TAC-RTX.

A sandwich chemiluminescent magnetic microparticle immunoassay for cryptococcal antigen detection

ABSTRACT Background Cryptococcosis is a global invasive mycosis associated with significant morbidity and mortality. Cryptococcal antigen (CrAg) testing from serum and cerebrospinal fluid (CSF) has been regarded as a gold standard for early diagnosis. This study aimed to develop and validate a rapid and sensitive sandwich chemiluminescent magnetic microparticle immunoassay (CMIA) for quantitative detection of CrAg in sera. Research design and methods CMIA is based on magnetic beads modified with capture antibodies and biotinylated antibodies and Streptavidin-polyHRP, where biotinylated antibodies functioned as the recognition element and Streptavidin-polyHRP as the signal component. Assay parameters were first optimized, and then assay performances were evaluated. Results Under optimized conditions, the total runtime of the CMIA was 22 min. The assay had a wide linear range (2 –10,000 ng/mL) and high analytical sensitivity (0.24 ng/mL), together with acceptable reproducibility, accuracy, and stability. Besides, it exhibited no cross-reactivity with other pathogens. Importantly, the assay showed 92.91% (95% CI, 80.97–93.02%) overall qualitative agreement with a commercial ELISA kit in a retrospective cohort of 55 cases with confirmed cryptococcal infection, and 72 controls without evidence of invasive fungal disease (IFD). Conclusion These results demonstrated that the present study paved a novel strategy for reliable quantitative detection of CrAg in sera.

Hierarchically Structured and Highly Dispersible MOF Nanozymes Combining Self-Assembly and Biomineralization for Sensitive and Persistent Chemiluminescence Immunoassay.

Metal-organic frameworks (MOF) are promising candidates for the construction of artificial nanozymes and have found applications in many fields. However, the preparation of nanosized MOF materials with high performance and good dispersibility is still a big challenge and is in great demand as signal labels for immunoassays. In this work, hierarchically structured and highly dispersible MOF nanoparticles were facilely prepared in a one-pot method. Self-assembled micelles from PEGylated hematin were used as structured templates to mediate the formation of zeolitic imidazole framework-8 (ZIF-8) nanoparticles in aqueous solution. The encapsulation of micelles in ZIF-8 frameworks produces well-dispersed nanoparticles and generates dual-confinement effects for catalytic hematin. Owing to the hierarchical structures, the formed MOF nanozymes show enhanced peroxidase-like activity and enable persistent chemiluminescence behaviors for the luminol system. Sandwich-type chemiluminescence immunoassays for carcinoembryonic antigen (CEA) were proposed using MOF nanozymes as signal labels, and good analytical performances were achieved. The combination of self-assembly and biomineralization may open new avenues for the development of MOF nanomaterials.

RETRACTED: Development of a highly sensitive chemiluminescence immunoassay using a novel signal-enhanced detection system for quantitation of durvalumab, an immune-checkpoint inhibitor monoclonal antibody used for immunotherapy of lung cancer

Durvalumab (DUR) is a human monoclonal antibody used for the immunotherapy of lung cancer. It is a novel immune-checkpoint inhibitor, which blocks the programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1) proteins and works to promote the normal immune responses that attack the tumour cells. To support the pharmacokinetic (PK) studies, therapeutic drug monitoring (TDM) and refining the safety profile of DUR, an efficient assay is required, preferably immunoassay. This study describes, for the first time, the development of a highly sensitive chemiluminescence immunoassay (CLIA) for the quantitation of DUR in plasma samples with enhanced chemiluminescence detection system. The CLIA protocol was conducted in 96-microwell plates and involved the non-competitive binding reaction of DUR to its specific antigen (PD-L1 protein). The immune complex of DUR with PD-L1 formed onto the inner surface of the assay plate wells was quantified by a chemiluminescence (CL)-producing horseradish peroxidase (HRP) reaction. The reaction employed 4-(1,2,4-triazol-1-yl)phenol (TRP) as an efficient enhancer of the HRP-luminol-hydrogen peroxide (H2O2) CL reaction. The optimum protocol of the proposed CLIA was established, and its validation parameters were assessed as per the guidelines for the validation of immunoassays for bioanalysis. The working dynamic range of the assay was 10-800pgmL-1 with a limit of detection (LOD) of 10.3pgmL-1. The assay enables the accurate and precise quantitation of DUR in human plasma at a concentration as low as 30.8pgmL-1. The CLIA protocol is simple and convenient; an analyst can analyse several hundreds of samples per working day. This high throughput property enables the processing of many samples in clinical settings. The proposed CLIA has a significant benefit in the quantitation of DUR in clinical settings for assessment of its PK, TDM and refining the safety profile.

Novel highly sensitive chemiluminescence immunoassay for quantitation of durvalumab using a signal enhanced horseradish peroxidase-luminol-hydrogen peroxide reaction for detection system

Durvalumab (DUR) is a human monoclonal antibody used for the immunotherapy of lung cancer. It is a novel immune-checkpoint inhibitor, which blocks the programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1) proteins and works to promote the normal immune responses that attack tumor cells. To support the pharmacokinetic (PK) studies, therapeutic drug monitoring (TDM) and refining the safety profile of DUR, an efficient assay is required, preferably immunoassay. This study describes, for the first time, the development and validation of a novel enhanced chemiluminescence immunoassay (CLIA) with high sensitivity and selectivity for the quantitation of DUR in plasma samples. The assay protocol was conducted in 96-microwell plates and involved the non-competitive binding reaction of DUR to its specific antigen (PD-L1 protein). The immune complex of DUR with PD-L1 formed on the inner surface of the assay plate wells was quantified by a chemiluminescence (CL)-producing horse radish peroxidase (HRP) reaction. The reaction employed 4-(1,2,4-triazol-1-yl)phenol (TRP) as an efficient enhancer of the HRP-luminol–hydrogen peroxide (H2O2) CL reaction. The optimum protocol of the proposed CLIA was established, and its validation parameters were assessed as per the guidelines for the validation of immunoassays for bioanalysis. The working dynamic range of the assay was 10–800 pg mL–1 with a limit of detection (LOD) of 10.3 pg mL–1. The assay enables the accurate and precise quantitation of DUR in human plasma at a concentration as low as 30.8 pg mL–1. The CLIA protocol is simple and convenient; an analyst can analyze several hundreds of samples per working day. This high throughput property enables the processing of many samples in clinical settings. The proposed CLIA has a significant benefit in the quantitation of DUR in clinical settings for assessment of its PK, TDM and refining the safety profile.

Establishment of Sensitive Sandwich-Type Chemiluminescence Immunoassay for Interleukin-18 in Urinary Samples.

Interleukin-18 (IL-18), a member of IL-1 cytokine superfamily, is deemed as an important indicator of the kidney disease. Herein a sandwich chemiluminescence immunoassay integrated with magnetic beads was conducted to detect IL-18 in kidney disease. The detection limit and linear range were 0.0044ng/mL and 0.01-2.7ng/mL, respectively. Satisfactory recoveries were ranged from 91.70 to 101.18% with the relative standard deviation below 10%; interference bias of most biomarkers were within allowable deviation range (± 15%). In summary, the whole study was successfully applied to detect IL-18 levels in urine samples for patients with kidney disease. The results showed that chemiluminescence immunoassay for IL-18 detection could be used in the clinical application.

Novel Chemiluminescence Immunoassay (CLIA) for the Sensitive Determination of Kidney Injury Molecule-1 in Human Urine

Kidney injury molecule 1 (KIM-1) is markedly upregulated in the proximal tubule after injury and is maladaptive when chronically expressed. A practical sensitive chemiluminescence immunoassay combined with magnetic bead separation for the determination of KIM-1 in human urine has been developed. Based on a sandwich-type immunoassay, the analyte is captured by the monoclonal antibodies (mAb) coated in magnetic beads and those labeled with the alkaline phosphatase. The changes of KIM-1 concentration levels were monitored by the CLIA for the early diagnosis of kidney disease. The established immunoassay exhibited a wide linear range from 0.5 to 81 ng/mL with a detection limit of 0.17 ng/mL. The recoveries, specificity, and interference results of the developed method were satisfactory. The whole analysis time was 30 min. The developed method was for the detection of kidney disease in patients. This work is a novel chemiluminescence immunoassay with excellent performance for the early diagnosis of kidney diseases.

Highly Sensitive Chemiluminescent Immunoassay of Mycotoxins Using ZIF-8-Derived Yolk-Shell Co Single-Atom Site Catalysts as Superior Fenton-like Probes.

Superior to traditional nanoscale catalysts, single-atom site catalysts (SASCs) show such merits as maximal catalysis efficiency and outstanding catalytic activity for the construction of analytical methodological platforms. Hereby, an in situ etching strategy was designed to prepare yolk-shell Co SASCs derived from ZIF-8@SiO2 nanoparticles. On the basis of direct chemical interactions between precursors and supports, the Co element with isolated atomic dispersion was anchored on ZIF-8@SiO2 nanoparticles. The Co SASCs possess high Fenton-like activity and thus can catalyze the decomposition of H2O2 to produce massive superoxide radical anions instead of singlet oxygen and hydroxyl radicals. With the activity for producing superoxide radical anion, Co SASCs can greatly improve the chemiluminescent (CL) response of a luminol system by 3133.7 times. Furthermore, the SASCs with active sites of Co-O5 moieties were utilized as the CL probes for establishment of an immunoassay method for sensitive detection of mycotoxins by adopting aflatoxin B1 as a mode analyte. The quantitation range is 10-1000 pg/mL, and the limit of detection is 0.44 pg/mL (3σ) for aflatoxin B1. The proof-of-principle work elucidates the practicability of direct chemical interactions between precursors and supports for forming SASCs with ultrahigh CL response, which can be extended to the exploitation of more sorts of SASCs for tracing biological binding events.

Novel highly sensitive chemiluminescence immunoassay for quantitation of durvalumab, an immune-checkpoint inhibitor monoclonal antibody used for immunotherapy of lung, using a signal enhanced horseradish peroxidase-luminol hydrogen peroxide reaction for detection system

Novel highly sensitive chemiluminescence immunoassay for quantitation of durvalumab, an immune-checkpoint inhibitor monoclonal antibody used for immunotherapy of lung, using a signal enhanced horseradish peroxidase-luminol hydrogen peroxide reaction for detection system

Establishment of a Chemiluminescence Immunoassay Combined with Immunomagnetic Beads for Rapid Analysis of Ochratoxin A.

Ochratoxin A (OTA) is a harmful mycotoxin and secondary metabolite produced by several species of Aspergillus and Penicillium. It is of vital importance to establish a sensitive method to detect OTA in various grains. A novel, highly sensitive chemiluminescence immunoassay was developed to determine OTA in wheat, corn, and poultry feed. The immunomagnetic beads were used as solid phase carriers and separators in the competitive chemiluminescence method. Anti-OTA monoclonal antibodies coated on the magnetic beads were applied as the capturing antibodies, in which OTA would compete with OTA-alkaline phosphatase in binding with OTA antibodies. The proposed method exhibited good linearity (R2 ≥ 0.999), adequate OTA recovery rate (83.60-102.50%), and good repeatability. The sensitivity of the proposed method was 2.05 pg/mL. In addition, the method was highly selective and showed no cross-reactions with other mycotoxins (e.g., AFB1, DON, ZEN). The developed method was applied in the analysis of wheat, corn, and two animal feeds successfully. The results obtained by the chemiluminescence method showed a high correlation with those obtained by the HPLC method (correlation coefficient 0.9958). This strategy shows great potential for other toxic and harmful mycotoxin detection. A novel highly rapid and sensitive chemiluminescence immunoassay was established for quantitation of OTA.

A sensitive chemiluminescence immunoassay based on immunomagnetic beads for quantitative detection of zearalenone

A sensitive chemiluminescence immunoassay based on immunomagnetic beads for quantitative detection of zearalenone

“Reconnoitering the Association of Interleukin-6 with Chronic Periodontitis and Covid-19: An Observational Study

Aim: The aim of the present study was to investigate comparatively the systemic levels of interleukin-6 in COVID-19 positive patients with/without chronic periodontitis and recovered COVID-19 patient with/without chronic periodontitis respectively. Methods: Total 200 consecutive confirmed cases were included and categorized equally into four groups- Group1A & Group 1B (COVID-19 positive), Group 2A & Group 2B (COVID-19 recovered),based on periodontal status along with Interleukin-6 levels. Peripheral blood samples were taken and Serum Interleukin-6 concentrations were tested using a highly sensitive (Chemiluminescence immunoassay) CLIA method on admission during hospital stay. Results: There were 50 subjects taken in all study groups. The mean age was 40.80, 38.02, 41.06, 38.98 in Group (1A,1B,2A&2B) respectively and the difference in mean age group was not significant (P>0.05). The mean interleukin-6 level was 26.0752, 1.5306, 4.1290, 0.7514 pg/ml in Group1A, 1B, 2A, 2B respectively and the difference was statistically significant (P-0.0001*). The mean difference in inter-group comparison was seen significant (P<0.05) among group1A vs(1B,2A,2B) & non-significant (P>0.05) among group1Bvs(2A,2B) & group2A vs 2B respectively. Conclusion: Chronic periodontitis must be included in diagnostic work-up to stratify SARS- CoV-2 severity.

Detection of enrofloxacin by flow injection chemiluminescence immunoassay based on cobalt hydroxide nanozyme.

The emergence and development of low-cost and high-efficiency nanozymes are promising to replace natural enzymes promoting the application of chemiluminescence immunoassays. Herein, a rapid and highly sensitive flow injection chemiluminescence immunoassay based on cobalt hydroxide (Co(OH)2) nanozyme was established to detect enrofloxacin (ENR) residues in food. In this system, Co(OH)2 nanosheets act as nanozymes to catalyze and amplify the chemiluminescence signal of theluminol-PIP-H2O2 system, as well as a carrier for immobilizing antibodies to form stable immunoprobes. In addition, carboxyl resin beads with good stability and biocompatibility were used as the base of the immunosensor to carry more coating antigens, based on the principle of competitive immunity and to achieve the rapid detection of ENR. Under optimal conditions, the linear workingrange is 0.0001 ~ 1000ng/mL, and the limit of detection (LOD) is 0.041pg/mL (S/N = 3). The method has been successfully applied to the analysis of aquatic products and poultry food. A non-enzyme immunosensor using Co(OH)2 nanosheets as antibody-conjugated carriers and peroxidase mimics for catalytic amplification of the chemiluminescence signal of luminol and using carboxyl resin beads as platform was designed to detect ENR residues in food.

Development of a highly sensitive chemiluminescence immunoassay for quantification of aggrecanase-generated ARGS aggrecan fragments in serum

ObjectiveCartilage degradation is a hallmark of osteoarthritis (OA). Aggrecan, a major proteoglycan of articular cartilage extracellular matrix (ECM), is degraded by ADAMTS-5 resulting in the release of ARGS-G2 fragments to synovial fluid and circulation. The aim was to quantify ARGS-G2 in the serum of OA patients using the huARGS immunoassay. MethodsThe immunoassay was produced under GMP conditions and the technical performance was assessed. The biological relevance of the immunoassay was assessed in the conditioned media from a bovine full-depth cartilage explant (BEX) model. The diurnal and inter-day variations of ARGS levels were evaluated in OA patients’ serum. Post-hoc analysis of huARGS was conducted in a sub-cohort of a phase III OA trial testing the safety and efficacy of oral salmon calcitonin. ResultsTechnical performance: huARGS demonstrated good technical performance. Biological relevance: ARGS release was induced by inflamatory facotrs stimulation compared to the vehicle group, reaching a peak at day 3 and gradually decreasing to base level at day 12. The ARGS release was suppressed by the addition of the ADAMTS-4/-5 activation inhibitor. Biological variation: No significant diurnal or inter-day effect was found. Phase III clinical trial: The participants in the lowest group (Q1) of baseline huARGS levels were more likely to progress radiographically than the highest group (Q4): OR 3.38[0.81-14.02]. ConclusionsThe huARGS shows good technical performance and low biological variation. It has the potential to aid drug development in various stages, both as a PD biomarker and identifying progressors who might be likely to respond to an OA drug.

Specific heptapeptide screened from pIII phage display library for sensitive enzyme-linked chemiluminescence immunoassay of vascular endothelial growth factor

It is challenging to explore specific, stable and cost-effective biorecognizing elements for a wide range of applications including biosensing and nanomedicine. As the primary pro-angiogenic factor, vascular endothelial growth factor (VEGF) plays crucial roles in tumor metastasis. It holds great significance to detect VEGF in clinical diagnostics. Especially, the level of the isoform VEGF165 is usually called as the key index of many malignant tumors. Herein, phage monoclones bound to VEGF165 were selected from the pIII phage display library. Based on the phage capture assay, the phage monoclone expressing peptide LSTSPHT exhibited the best affinity and specificity against VEGF165. Then, peptide V (with the peptide sequence of LSTSPHTGGGSC) was synthesized as VEGF165 capturer to develop an enzyme-linked chemiluminescence immunoassay (ELCLIA). Under the optimal conditions, the proposed ELCLIA method showed wide linear range (10–1000 pg mL−1) and lower limit of detection (5.7 pg mL−1). Moreover, the as-developed ELCLIA was capable of detecting VEGF165 in human serum samples accurately and reproducibly. Due to its good selectivity, stability and cost-effectiveness, the VEGF165-specific peptide is prospected as a novel biointerface in sensing and tumor metastasis related diagnosis and therapy.

Development of a sensitive and stable chemiluminescent immunoassay for detection of birch pollen allergic specific IgE based on recombinant Bet v1 protein

BackgroundQuantitative detection of allergens is of great significance for clarifying the cause, treatment, and prevention of allergy disease. Birch pollen is one of the most common inhalational allergens and Bet v1 is the major component allergen of birch allergen. This study aims to develop a stable and sensitive chemiluminescence immunoassay (CLIA) for the detection of birch pollen allergic specific IgE (sIgE) based on recombinant Bet v1 (rBet v1) protein.MethodsrBet v1 protein was expressed in Escherichia coli and purified. Then rBet v1 was applied to detect sIgE in human serum. The performance of the established CLIA was evaluated and compared with Phadia rBet v1 fluorescence enzyme immunoassay (FEIA) system.ResultsThe developed CLIA for sIgE to rBet v1 detection shows excellent performance. The assay showed a linear range from 0.1 to 100 IU/mL, with a low detection limit of 0.06 IU/mL. A total of 164 samples were evaluated by CLIA and compared with the results of FEIA. The positive, negative, and total coincidence rate was 90.6% (87/96), 91.2% (62/68), and 90.9% (149/164), respectively. The r-value of Spearman's rank correlation analysis was 0.935 (P < 0.001). The use of high levels of bilirubin (50 mg/dL), hemoglobin (400 mg/dL) and lipid (2000 mg/dL) didn't interfere with the results.ConclusionsThe proposed CLIA exhibits excellent performance for the detection of rBet v1 specific IgE. It can be a reliable tool for the early diagnosis of hypersensitivity.

Covert cases of Severe Acute Respiratory Syndrome Coronavirus 2: An obscure but present danger in regions endemic for Dengue and Chikungunya viruses

BackgroundThe impact of SARS-CoV-2 in regions endemic for both Dengue and Chikungunya is still not fully understood. Considering that symptoms/clinical features displayed during Dengue, Chikungunya and SARS-CoV-2 acute infections are similar, undiagnosed cases of SARS-CoV-2 in co-endemic areas may be more prevalent than expected. This study was conducted to assess the prevalence of covert cases of SARS-CoV-2 among samples from patients with clinical symptoms compatible with either Dengue or Chikungunya viral infection in the state of Espírito Santo, Brazil.MethodsPresence of immunoglobulin G (IgG) antibody specific to SARS-CoV-2 nucleoprotein was detected using a chemiluminescent microparticle immunoassay in samples from 7,370 patients, without previous history of COVID-19 diagnosis, suspected of having either Dengue (n = 1,700) or Chikungunya (n = 7,349) from December 1st, 2019 to June 30th, 2020.FindingsCovert cases of SARS-CoV-2 were detected in 210 (2.85%) out of the 7,370 serum samples tested. The earliest undiagnosed missed case of COVID-19 dated back to a sample collected on December 18, 2019, also positive for Dengue Virus. Cross-reactivity with either Dengue virus or other common coronaviruses were not observed.InterpretationOur findings demonstrate that concomitant Dengue or Chikungunya outbreaks may difficult the diagnosis of SARS-CoV-2 infections. To our knowledge, this is the first study to demonstrate, with a robust sample size (n = 7,370) and using highly specific and sensitive chemiluminescent microparticle immunoassay method, that covert SARS-CoV-2 infections are more frequent than previously expected in Dengue and Chikungunya hyperendemic regions. Moreover, our results suggest that SAR-CoV-2 cases were occurring prior to February, 2020, and that these undiagnosed missed cases may have contributed to the fast expansion of SARS-CoV-2 outbreak in Brazil. Data presented here demonstrate that in arboviral endemic regions, SARS-CoV-2 infection must be always considered, regardless of the existence of a previous positive diagnosis for Dengue or Chikungunya.

Development of a chemiluminescence immunoassay for detection of tenuazonic acid mycotoxin in fruit juices with a specific camel polyclonal antibody.

The natural mycotoxin tenuazonic acid (TeA) in foods is identified as the most toxic mycotoxin among the over 70 kinds of secondary toxic metabolites produced by Alternaria alternata. Some hapten-antibody-mediated immunoassays have been developed for TeA detection in food samples, but these methods show unsatisfactory sensitivity and specificity. In this study, a rationally designed hapten for TeA mycotoxin generated with computer-assisted modeling was prepared to produce a highly specific camel polyclonal antibody, and an indirect competitive chemiluminescence enzyme immunoassay (icCLEIA) was established with a limit of detection of 0.2 ng mL-1 under optimized conditions. The cross-reactivity results showed that several analogs and some common mycotoxins had negligible recognition by the anti-TeA polyclonal antibody. The average recoveries spiked in fruit juices were determined to be 92.7% with an acceptable coefficient of variation, and good correlations between icCLEIA and liquid chromatography tandem mass spectrometry (LC-MS/MS) results were obtained in spiked samples. This developed icCLEIA for TeA detection with significantly improved sensitivity and satisfactory specificity is a promising alternative for environmental monitoring and food safety.

A Rapid and Highly Sensitive Chemiluminescent Method to Quantify HPV16E7 Antibody Based on Immunomagnetic Separation Methods.

In order to detect anti-HPV16E7 antibody in serum, a highly sensitive and rapid detection method based on chemiluminescence immunoassay and immunomagnetic separation was introduced. The technique that was developed is a novel, sensitive chemiluminescence (CL) immunoassay for HPV16E7 antibody detection. Balb/C mice were immunized with HPV16E7 fusion protein to prepare monoclonal antibody against HPV16E7. The biotinylated antigen was prepared as immunomagnetic beads and its stability was tested (IMBs). The protocol used horseradish peroxidase (HRP) labeled HPV16E7 antigen and immunomagnetic beads (IMBs). The antibody induced the formation of IMBs-mAbs HPV16E7-HRP labeled antibody structures. IMBs were applied to capture CEA and immobilize CEA through the external magnetic field. Oxidized luminescence substrate can be catalyzed by HRP on antibody surface to generate optical signals which were detected by luminometer. HPV16E7 monoclonal antibody was prepared and validated. The HPV16E7 antigen can efficiently bind to the bead with a conjugation rate of 72%. The biological activity of IMBs did not decrease significantly when stored in the dark at 4℃ for 2 months. The sensitivity and stability of this proposed method were excellent and showed a good linear relationship (Y = 1.3203 X + 0.7, R2 = 0.9952). This proposed technique showed excellent performance in quantitative measurement of HPV6E7 and was expected to be used in clinical detection.

Chemiluminescence immunoassay approach to quantify Bisphenol S in canned beverage using a NSP-SA-labeled specific monoclonal antibody

Bisphenol S (BPS) is a major alternative to Bisphenol A (BPA) newly applied in food packing material and disrupts reproductive and developmental endpoints through endocrine pathways. This study aimed to develop a rapid, sensitive, and accurate chemiluminescence immunoassay (CLIA) for the detection of BPS in canned beverage. Anti-BPS monoclonal antibody (mAb) was generated by immunizing Balb/c mice with immunogen (BPS–BSA conjugation). CLIA assay conditions, including 3-[9-(((3-(N-succinimidyloxycarboxypropyl) [4-methxylphenyl] sulfonyl) amine) carboxyl]-10-acridiniumyl)-1-propanesulfonate inner salt (NSP-SA-NHS) labeling ratio (1:40), antigen concentration (1 μg mL−1) and antibody titer (1:8000; 125 ng mL−1 in PBS (0.01 M, pH 7.4)) were determined, respectively. The half inhibition concentration (IC50), detection limit (IC10), and working range of the CLIA in canned beverage were 0.04, 1.48, and 0.32–5 ng mL−1, respectively. Cross-reactivity with other bisphenols (4,4′-thiodiphenol, Bisphenol F, 4,4′- dihydroxy benzophenone, Bisphenol A and Bisphenol B) was less than 0.56%, and the recovery rates of BPS in canned beverage ranged from 80 to 109.2% (intra-assay) and from 82 to 108.4% (inter-assay). The results of CLIA were compared with high-performance liquid chromatography–UV (HPLC–UV) analysis, showing a good correlation of 0.956. After proper sample pre-treatment, this method allows relatively large amounts of sample analysis in a limited time period (30 min). Thus, it was deemed suitable and efficient for routine screening of BPS in canned beverage.