A strategy for sensitivity and specificity enhancements in prostate specific antigen-α1-antichymotrypsin detection based on surface plasmon resonance

Cuong Cao, Jun Pyo Kim, Byung Woo Kim, Heeyeop Chae, Hyun C. Yoon, Sang Sik Yang, Sang Jun Sim

Research output: Contribution to journalArticlepeer-review

128 Citations (Scopus)


A biochip based on surface plasmon resonance was fabricated to detect prostate specific antigen-α1-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.

Original languageEnglish
Pages (from-to)2106-2113
Number of pages8
JournalBiosensors and Bioelectronics
Issue number11
Publication statusPublished - 2006 May 15
Externally publishedYes


  • Biotinylation
  • Enhancement
  • Oligo(ethylene glycol)
  • Prostate specific antigen
  • Self-assembled monolayer
  • Surface plasmon resonance

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry


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