Wang Chongwen, Yang Xingsheng, Zheng Shuai, Cheng Xiaodan, Xiao Rui, Li Qingjun, Wang Wenqi, Liu Xiaoxian, Wang Shengqi
College of Life Sciences, Anhui Agricultural University, Hefei, 230036, PR China.
Beijing Institute of Radiation Medicine, Beijing, 100850, PR China.
Sens Actuators B Chem. 2021 Oct 15;345:130372. doi: 10.1016/j.snb.2021.130372. Epub 2021 Jun 29.
Rapid and accurate diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A virus (FluA) antigens in the early stages of virus infection is the key to control the epidemic spread. Here, we developed a two-channel fluorescent immunochromatographic assay (ICA) for ultrasensitive and simultaneous qualification of the two viruses in biological samples. A high-performance quantum dot nanobead (QB) was fabricated by adsorption of multilayers of dense quantum dots (QDs) onto the SiO surface and used as the highly luminescent label of the ICA system to ensure the high-sensitivity and stability of the assay. The combination of monodispersed SiO core (∼180 nm) and numerous carboxylated QDs formed a hierarchical shell, which ensured that the QBs possessed excellent stability, superior fluorescence signal, and convenient surface functionalization. The developed ICA biosensor achieved simultaneous detection of SARS-CoV-2 and FluA in one test within 15 min, with detection limits reaching 5 pg/mL for SARS-CoV-2 antigen and 50 pfu/mL for FluA H1N1. Moreover, our method showed high accuracy and specificity in throat swab samples with two orders of magnitude improvement in sensitivity compared with traditional AuNP-based ICA method. Hence, the proposed method is a promising and convenient tool for detection of respiratory viruses.
在病毒感染早期快速准确地诊断严重急性呼吸综合征冠状病毒2（SARS-CoV-2）和甲型流感病毒（FluA）抗原是控制疫情传播的关键。在此，我们开发了一种双通道荧光免疫层析分析（ICA）方法，用于对生物样本中的两种病毒进行超灵敏同时定量检测。通过将多层致密量子点（QDs）吸附到SiO表面制备了一种高性能量子点纳米珠（QB），并将其用作ICA系统的高发光标记，以确保检测的高灵敏度和稳定性。单分散的SiO核（约180 nm）与大量羧基化QDs的组合形成了分层壳层，这确保了QB具有优异的稳定性、卓越的荧光信号和便捷的表面功能化。所开发的ICA生物传感器能够在15分钟内一次检测中同时检测SARS-CoV-2和FluA，SARS-CoV-2抗原的检测限达到5 pg/mL，FluA H1N1的检测限达到50 pfu/mL。此外，我们的方法在咽拭子样本中显示出高准确性和特异性，与传统的基于金纳米颗粒（AuNP）的ICA方法相比，灵敏度提高了两个数量级。因此，所提出的方法是一种用于检测呼吸道病毒的有前景且便捷的工具。
