Herein, we present a novel sandwich fluorescence enzyme linked immunosorbent assay (ELISA) for highly sensitive detection of Hepatitis B virus surface antigen (HBsAg) based on glucose oxidase (GOx)-induced fluorescence quenching of mercaptopropionic acid-modified CdTe quantum dots (MPA-QDs). In this system, hydrogen peroxide (H_{2}O_{2}) sensitive MPA-QDs was used as a signal output, and glucose oxidase (GOx) was used as label which can generate H_{2}O_{2} via catalytic oxidation of glucose. The proposed method showed dynamic linear detection of HBsAg both in the range of 47pgmL^{-1} ~ 380pgmL^{-1} and 0.75ngmL^{-1} ~ 12.12ngmL^{-1}. The detection limit of the proposed fluorescence ELISA was 1.16pgmL^{-1}, which was approximately 430-fold lower than that of horseradish peroxidase (HRP)-based conventional ELISA. The average recoveries for HBsAg-spiked serum samples ranged from 98.0% to 126.8% with the relative standard derivation below 10%, thus indicating acceptable precision and high reproducibility of the proposed fluorescence ELISA for HBsAg detection. Additionally, the developed method showed no false positive results analyzing 35 real HBsAg-negative serum samples, and exhibited excellent agreement (R^{2}=0.9907) with a commercial time-resolved fluorescence immunoassay (TRFIA) kit for detecting 31 HBsAg-positive serum samples. In summary, the proposed method based on fluorescence quenching of H_{2}O_{2} sensitive QDs is considerably to be an excellent biodetection platform with ultrahigh sensitivity, good accuracy and excellent reliability.
【저자키워드】 Hepatitis B virus surface antigen, Fluorescence ELISA, Glucose oxidase, H(2)O(2) sensitive quantum dots,