Prostate specific antigen detection using microgapped electrode array immunosensor with enzymatic silver deposition.
BACKGROUND
Analysis of trace proteins plays an essential role in the fields of biomedical research and clinical diagnosis. Development of methods for the detection of proteins at very low concentrations has historically been a challenge in immunochemistry. We have developed an electrical immunosensor for the detection of prostate specific antigen (PSA).


METHODS
The electrical immunosensor uses a microgapped interdigitated electrode array (MGIDEA) based on enzymatic silver deposition reaction. The deposition of silver was dispersed over the microgaps and allows the microgapped interdigitated electrodes to be electrically connected, resulting in an increase in electrical conductance of MGIDEA that is used to quantify the analyte concentration. We used this electrical immunosensor to measure PSA in human serum samples from patients with prostate diseases.


RESULTS
This electrical immunosensor exhibited a linear response with PSA concentrations over a 6-decade range from 1.0 pg/L to 1.0 microg/L, with detection limit of 0.9 pg/L. PSA concentrations using this immunosensor agreed within 10% of those obtained using a commercial chemiluminescent immunoassay.


CONCLUSIONS
The MGIDEA method has characteristics (analyte specific, low background, low limit of detection) that provide potential for molecular detection in various biomedical areas.
Huang
Yong
Y
State Key Laboratory for Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering, Hunan University, Changsha, China.
Wang
Tai-Hong
TH
Jiang
Jian-Hui
JH
Shen
Guo-Li
GL
Yu
Ru-Qin
RQ
D000911:Antibodies, Monoclonal / Q000737:chemistry; D014408:Biomarkers, Tumor / Q000097:blood*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D017430:Prostate-Specific Antigen / Q000097:blood*; D011469:Prostatic Diseases / Q000097:blood*; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen