State Key Laboratory of Food Science and Technology, Nanchang University, 235 Nanjing East Road, Nanchang 330047, PR China.
The People's Hospital in Jiangxi Province, Nanchang 330006, PR China.
Talanta. 2018 May 1;181:258-264. doi: 10.1016/j.talanta.2018.01.026. Epub 2018 Jan 11.
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 (HO) sensitive MPA-QDs was used as a signal output, and glucose oxidase (GOx) was used as label which can generate HO via catalytic oxidation of glucose. The proposed method showed dynamic linear detection of HBsAg both in the range of 47pgmL ~ 380pgmL and 0.75ngmL ~ 12.12ngmL. The detection limit of the proposed fluorescence ELISA was 1.16pgmL, 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=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 HO sensitive QDs is considerably to be an excellent biodetection platform with ultrahigh sensitivity, good accuracy and excellent reliability.
在此，我们提出了一种新颖的夹心荧光酶联免疫吸附测定（ELISA）方法，用于基于葡萄糖氧化酶（GOx）诱导巯基丙酸修饰的CdTe 量子点（MPA-QDs）的荧光猝灭，对乙型肝炎病毒表面抗原（HBsAg）进行高灵敏检测。在该体系中，使用对过氧化氢（HO）敏感的 MPA-QDs 作为信号输出，并用葡萄糖氧化酶（GOx）作为标记物，其可以通过催化氧化葡萄糖生成 HO。所提出的方法在 47pgmL 至 380pgmL 和 0.75ngmL 至 12.12ngmL 的范围内对 HBsAg 表现出动态线性检测。该荧光 ELISA 的检测限为 1.16pgmL，大约比辣根过氧化物酶（HRP）基于的传统 ELISA 低 430 倍。对于 HBsAg 加标血清样品，平均回收率在 98.0%至 126.8%之间，相对标准偏差低于 10%，表明该方法对 HBsAg 的检测具有可接受的精密度和高重现性。此外，该方法分析 35 份实际 HBsAg 阴性血清样本时没有出现假阳性结果，与用于检测 31 份 HBsAg 阳性血清样本的商业时间分辨荧光免疫分析（TRFIA）试剂盒具有极好的一致性（R=0.9907）。总之，该方法基于 HO 敏感 QDs 的荧光猝灭，是一种具有超高灵敏度、良好准确性和出色可靠性的优异生物检测平台。
