Blue-emitting SiO2-coated Si-doped ZnSeS quantum dots conjugated aptamer-molecular beacon as an electrochemical and metal-enhanced fluorescence biosensor for SARS-CoV-2 spike protein
Blue-emitting SiO2-coated Si-doped ZnSeS quantum dots conjugated aptamer-molecular beacon as an electrochemical and metal-enhanced fluorescence biosensor for SARS-CoV-2 spike protein
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DOI：
10.1016/j.aca.2023.341926
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发表时间：
2023-10-20
影响因子：
6.2
通讯作者：
Yang，Zhugen
中科院分区：
文献类型：
--
作者：
Adegoke，Oluwasesan;Oyinlola，Kayode;Yang，Zhugen
2020年1月初首次报告的严重急性呼吸系统综合征冠状病毒2型（SARS-CoV-2）爆发继续困扰着世界公共卫生系统。本文报道了一种新型的SARS-CoV-2 S蛋白金属增强荧光（MEF）电化学生物传感器的研制。为了开发MEF生物传感器，新合成的SiO2包覆的Si掺杂的ZnSeS量子点（QD），并结合到适体分子信标（Apta-MB）探针。此后，用作局部表面等离子体共振（LSPR）信号放大器的阳离子AuNP在QDs-Apta-MB缀合物上自组装以形成QDs-Apta-MB-AuNP探针。为了开发电化学生物传感器，在碳纳米纤维修饰的丝网印刷碳电极上进行QDs-Apta-MB测定。采用循环伏安法（CV）、微分脉冲伏安法（DPV）和电化学阻抗谱（EIS）对电极表面进行了表征，同时采用分光光度法、光谱法、荧光偏振法和电子显微镜技术对材料进行了表征。在优化的实验条件下，量子点与Apta-MB结合，猝灭量子点的荧光，并与SARS-CoV-2S蛋白结合，利用不同大小和形状的阳离子金纳米粒子的LSPR信号调谐荧光信号，获得增强的灵敏度。另一方面，使用用NaAc-KAc-TrizmaAc-KSCN-Borax缓冲的[Fe（CN）6]/K3-/4-作为电解质溶液，来自CV和DPV图的QD的阳极峰被解开。电化学检测SARS-CoV-2S蛋白是通过系统增加DPV图中产生的量子点阳极峰电流来实现的。QDs-Apta-MB-AuNP MEF探针对SARS-CoV-2 S蛋白的检测限为8.9 fg/mL，QDs-Apta-MB电化学探针的检测限为10.5 pg/mL。用QDs-Apta-MB-AuNP MEF探针检测唾液中SARS-CoV-2S蛋白。
The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which was first reported in early January 2020, continues to devastate the worlds public health system. Herein, we report on the development of a novel metal-enhanced fluorescence (MEF) and electrochemical biosensor for SARS-CoV-2 spike (S) protein. To develop the MEF biosensor, SiO2-coated Si-doped ZnSeS quantum dots (QDs) were newly synthesized and conjugated to an aptamer-molecular beacon (Apta-MB) probe. Thereafter, cationic AuNPs, used as a localised surface plasmon resonance (LSPR) signal amplifier, were self-assembled on the QDs-Apta-MB conjugate to form a QDs-Apta-MB-AuNP probe. To develop the electrochemical biosensor, the QDs-Apta-MB assay was carried out on a carbon nanofiber-modified screen-printed carbon electrode. Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were used to characterize the electrode surface whilst spectrophotometric, spectroscopic, fluorescence polarization and electron microscopic techniques were used to characterize the materials. Under optimal experimental conditions, the QDs binding to the Apta-MB, quenched the QDs’ fluorescence and with SARS-CoV-2 S protein binding to the Apta-MB, LSPR signal from cationic AuNPs of different sizes and shapes were used to tune the fluorescence signal to obtain enhanced sensitivity. On the other hand, using [Fe(CN)6]/K3−/4-buffered with NaAc-KAc-TrizmaAc-KSCN-Borax as the electrolyte solution, anodic peaks of the QDs from the CV and DPV plots were unravelled. Electrochemical detection of SARS-CoV-2 S protein was accomplished by a systematic increase in the QDs anodic peak current generated from the DPV plots. The limits of detection obtained for the SARS-CoV-2 S protein were 8.9 fg/mL for the QDs-Apta-MB-AuNP MEF probe and ∼0.5 pg/mL for the QDs-Apta-MB electrochemical probe. Detection of SARS-CoV-2 S protein in saliva was demonstrated using the QDs-Apta-MB-AuNP MEF probe.