A strategy for sensitivity and specificity enhancements in prostate specific antigen-alpha1-antichymotrypsin detection based on surface plasmon resonance.
A biochip based on surface plasmon resonance was fabricated to detect prostate specific antigen-alpha(1)-antichymotrypsin (PSA-ACT complex) in both HBS buffer and human serum. To reduce non-specific binding and steric hindrance effect, the chemical surface of the sensor chips was constructed by using various oligo(ethylene glycol) mixtures of different molar ratios of HS(CH2)11(OCH2CH2)6OCH2COOH and HS(CH2)11(OCH2CH2)3OH. The self-assembled monolayers were biotinylated to facilitate the immobilization of streptavidin. Using the chip surfaces, PSA-ACT complex in HBS buffer and human serum was detected at 20.7 and 47.5 ng/ml by primary immunoresponse, respectively. However, the limit of detection could be simply enhanced by a sandwich strategy to improve the sensitivity and specificity of the immunoassay. An intact PSA polyclonal antibody was used as an amplifying agent in the strategy. As a result, PSA-ACT complex concentrations as low as 10.2 and 18.1 ng/ml were found in the HBS buffer and human serum sample, respectively. The result indicates that this approach could satisfy our goal without modifying the secondary interactant.
Cao
Cuong
C
Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
Kim
Jun Pyo
JP
Kim
Byung Woo
BW
Chae
Heeyeop
H
Yoon
Hyun C
HC
Yang
Sang Sik
SS
Sim
Sang Jun
SJ
D001710:Biotin; D019855:Ethylene Glycol; D006801:Humans; D007118:Immunoassay; D017430:Prostate-Specific Antigen / Q000032:analysis* / Q000378:metabolism; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000379:methods*; D000514:alpha 1-Antichymotrypsin / Q000032:analysis* / Q000378:metabolism
D000514:alpha 1-Antichymotrypsin; D001710:Biotin; D017430:Prostate-Specific Antigen; D019855:Ethylene Glycol