School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
College of Life Science and Technology, Guangxi University, Nanning 530004, China.
Biosensors (Basel). 2022 Nov 17;12(11):1034. doi: 10.3390/bios12111034.
For the first time, a nanobiosensor was established for Sorghum mosaic virus (SrMV) detection. The biosensor consists of cadmium telluride quantum dots (CdTe QDs) conjugated to the specific antibody (Ab) against SrMV coat protein (CP) and carbon quantum dots (C QDs) labeled with SrMV coat protein. The formation of the fluorophore-quencher immunocomplex CdTe QDs-Ab+C QDs-CP led to a distinct decrease in the fluorescence intensity of CdTe QDs. Conversely, the emission intensity of CdTe QDs recovered upon the introduction of unlabeled CP. The developed biosensor showed a limit of detection of 44 nM in a linear range of 0.10-0.54 μM and exhibited the strongest fluorescence intensity (about 47,000 a.u.) at 552 nm. This strategy was applied to detect purified CP in plant sap successfully with a recovery rate between 93-103%. Moreover, the feasibility of the proposed method was further verified by the detection of field samples, and the results were consistent with an enzyme-linked immunosorbent assay (ELISA). Contrarily to ELISA, the proposed biosensor did not require excessive washing and incubation steps, thus the detection could be rapidly accomplished in a few minutes. The high sensitivity and short assay time of this designed biosensor demonstrated its potential application in situ and rapid detection. In addition, the fluorescence quenching of CdTe QDs was attributed to dynamic quenching according to the Stern-Volmer equation.
首次建立了用于检测高粱花叶病毒（SrMV）的纳米生物传感器。该生物传感器由与 SrMV 外壳蛋白（CP）特异性抗体（Ab）偶联的碲化镉量子点（CdTe QDs）和 SrMV 外壳蛋白标记的碳量子点（C QDs）组成。荧光团猝灭免疫复合物 CdTe QDs-Ab+C QDs-CP 的形成导致 CdTe QDs 的荧光强度明显降低。相反，在引入未标记的 CP 时，CdTe QDs 的发射强度恢复。开发的生物传感器在 0.10-0.54 μM 的线性范围内检测限为 44 nM，在 552 nm 处表现出最强的荧光强度（约 47,000 a.u.）。该策略成功应用于检测植物汁液中的纯化 CP，回收率在 93-103%之间。此外，通过检测现场样本进一步验证了该方法的可行性，结果与酶联免疫吸附测定（ELISA）一致。与 ELISA 相反，该生物传感器不需要过多的洗涤和孵育步骤，因此可以在几分钟内快速完成检测。该设计的生物传感器具有高灵敏度和短测定时间，证明了其在原位和快速检测中的潜在应用。此外，根据斯特恩-沃尔默方程，CdTe QDs 的荧光猝灭归因于动态猝灭。
