Novel chemiluminescent imaging microtiter plates for high-throughput detection of multiple serum biomarkers related to Down's syndrome via soybean peroxidase as label enzyme

Simultaneous detection of three biomarkers related to acute myocardial infarction based on immunosensing biochip

An immunosensing biochip for simultaneous detection of three biomarkers related to acute myocardial infarction (AMI) was developed based on anionic soybean peroxidase (SBP) functionalized nanoprobe and chemiluminescent imaging. The nanoprobes (Ab2-SiO₂-SBP) were fabricated by co-immobilization of SBP and one of the detection polyclonal antibodies, anti-cardiac troponin I antigen (anti-cTnI), anti-creatine kinase-MB (anti-CK-MB) and anti-myoglobin (anti-Myo), on the silica nanoparticle surface. The detection sensitivity was enhanced since the large surface area of silica carriers increased the loading of SBP for per sandwiched immunoreaction. The immunosensing biochip designed as 3 × 8 wells array was constructed by simultaneously immobilizing three capture monoclonal antibodies on the same one microtiter well with 2 × 3 active spots. In the presence of target protein, the nanoprobes will be attached onto the spots with high specificity through the sandwiched immunoreactions, which triggered the chemiluminescence (CL) signals on each sensing site of the microtiter plates and allowed to CL imaging of three biomarkers in one well at the same time. Therefore, the proposed biochip was a promising convenient strategy for simultaneous detection of cTnI, CK-MB and Myo, which showed potential application for multianalyte determination in clinical diagnostics.

A portable chemiluminescence imaging immunoassay for simultaneous detection of different isoforms of prostate specific antigen in serum

A multianalyte chemiluminescence (CL) imaging immunoassay strategy for sensitive detection of different isoforms of prostate specific antigen (PSA) was developed. The microtiter plates were fabricated by simultaneously immobilizing of free-PSA (f-PSA) and total-PSA (t-PSA) capture antibody on nitrocellulose (NC) membrane. Each of the array were spotted in replicates of six spots within a spacing of 2mm. 16 or 48 detection wells were integrated on a single NC membrane and each well could be used as a microreactor and microanalysis chamber. Under a sandwiched immunoassay, the CL signals on each sensing site were collected by a charge-coupled device (CCD), presenting an array-based chemiluminescence imaging. Soybean peroxidase (SBP) was used to label f-PSA or t-PSA monoclonal antibody. With the amplification effects of two enhancers, 3-(10'-phenothiazinyl) propane-1-sulfonate (SPTZ) and 4-morpholinopyridine (MORP), the CL intensity could significantly enhanced, which improved the sensing sensitivity and detection limit. Under the optimal conditions, the linear response to the analyte concentration ranged from 0.01-36.7ng/mL and 0.02-125ng/mL for f-PSA and t-PSA, respectively. The results for the detection of forty serum samples from prostate cancer patients and cancer-free patients showed good agreement with the clinical data, suggesting that the proposed assay had acceptable accuracy. The proposed CL imaging immunoassay possess high throughput and acceptable reproducibility, stability and accuracy, which made it great potential to available to distinguish different isoforms of PSA in serum samples.