High-sensitivity detection of carbohydrate antigen 15-3 using a gold/zinc oxide thin film surface plasmon resonance-based biosensor.
We report that gold/zinc oxide (Au/ZnO) nanocomposite films were effectively employed to enhance the performance of surface plasmon resonance (SPR) for the detection of tumor markers. Carbohydrate antigen 15.3 (CA15-3), a tumor marker for breast cancer, was chosen as a model analyte. We analyzed intensity response to the samples at various concentrations (0.0125 U/mL to 160 U/mL) in pleural fluid to evaluate the detection capability of the SPR biosensor based on Au/ZnO thin films. The linear range extended from 1 to 40 U/mL with a correlation coefficient of R(2) = 0.991 and a limit of detection reaching 0.025 U/mL at a signal-to-noise ratio of 3:1. Compared with the degree of the shift in SPR intensity induced by the specific binding event between antibody and antigen, the change of intensity on the Au/ZnO layers was increased by at least 2 fold over that on the gold/chromium (Au/Cr) layers. In addition, we determined that the Au/ZnO layers allowed for a detection limit 4 times lower than the Au/Cr layers, which are in widespread use as the sensing interfaces in current SPR-based detectors. In conclusion, the use of Au/ZnO films greatly enhanced the SPR signal yield for this bimolecular interaction and showed high sensitivity.
Chang
Chia-Chen
CC
Institute of Biomedical Engineering, National Taiwan University, Taipei 10617, Taiwan.
Chiu
Nan-Fu
NF
Lin
David Shenhsiung
DS
Chu-Su
Yu
Y
Liang
Yang-Hung
YH
Lin
Chii-Wann
CW
D000818:Animals; D000906:Antibodies / Q000276:immunology; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000032:analysis* / Q000276:immunology; D002857:Chromium / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay; D035422:Pleural Cavity / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties; D015034:Zinc Oxide / Q000737:chemistry*
D000906:Antibodies; D015295:Antigens, Tumor-Associated, Carbohydrate; D002857:Chromium; D006046:Gold; D015034:Zinc Oxide