title: Development of an Au/ZnO thin film surface plasmon resonance-based biosensor immunoassay for the detection of carbohydrate antigen 15-3 in human saliva.
abstract: OBJECTIVE
  To evaluate a novel surface plasmon resonance (SPR) system for the direct measurement of tumor marker carbohydrate antigen 15-3 (CA15-3) in human saliva.
  
  
  METHODS
  We measured the presence of the tumor marker carbohydrate antigen 15-3 (CA15-3) in human saliva using 2 different surface plasmon resonance (SPR) systems. To compare the sensitivity of an SPR biosensor based on thin-film Au/ZnO and the Biacore SPR system, we prepared CA15-3 samples in saliva and analyzed intensity responses to the samples at various concentrations of CA15-3.
  
  
  RESULTS
  The linear detection range of CA15-3 in human saliva with the SPR system based on thin-film Au/ZnO was 2.5-20 U/mL (the cut-off point in cancer patients is around 4 U/mL). The linear range with the Biacore SPR system was 40-300 U/mL.
  
  
  CONCLUSIONS
  These results show that thin-film Au/ZnO-based SPR systems have higher sensitivity and can be used for measuring the levels of CA15-3 in human saliva without concentrating the samples.
authors.affiliation: Institute of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Yang-Hung
authors.initials: YH
authors.lastname: Liang
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Chang
authors.forename: Chien-Cheng
authors.initials: CC
authors.lastname: Chen
authors.forename: Yu
authors.initials: Y
authors.lastname: Chu-Su
authors.forename: Chii-Wann
authors.initials: CW
authors.lastname: Lin
mesh_terms: D000328:Adult; D055910:Antibodies, Immobilized / Q000276:immunology; D002138:Calibration; D005260:Female; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008875:Middle Aged; D018396:Mucin-1 / Q000032:analysis*; D012463:Saliva / Q000378:metabolism*; D020349:Surface Plasmon Resonance / Q000379:methods*; D055815:Young Adult; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D055910:Antibodies, Immobilized; D018396:Mucin-1; D006046:Gold; D015034:Zinc Oxide