Adeel Muhammad, Asif Kanwal, Alshabouna Fahad, Canzonieri Vincenzo, Rahman Md Mahbubur, Ansari Sajid Ali, Güder Firat, Rizzolio Flavio, Daniele Salvatore
Department of Molecular Sciences and Nanosystems, Ca'Foscari University of Venice, 30123, Venezia, Italy.
Pathology Unit, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, 33081, Aviano, Italy.
Biosens Bioelectron X. 2022 Dec;12:100256. doi: 10.1016/j.biosx.2022.100256. Epub 2022 Sep 24.
The proliferation and transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), or the (COVID-19) disease, has become a threat to worldwide biosecurity. Therefore, early diagnosis of COVID-19 is crucial to combat the ongoing infection spread. In this study we propose a flexible aptamer-based electrochemical sensor for the rapid, label-free detection of SARS-CoV-2 spike protein (SP). A platform made of a porous and flexible carbon cloth, coated with gold nanoparticles, to increase the conductivity and electrochemical performance of the material, was assembled with a thiol functionalized DNA aptamer S-Au bonds, for the selective recognition of the SARS-CoV-2 SP. The various steps for the sensor preparation were followed by using scanning electron microscopy, cyclic voltammetry and differential pulse voltammetry (DPV). The proposed platform displayed good mechanical stability, revealing negligible changes on voltammetric responses to bending at various angles. Quantification of SARS-CoV-2 SP was performed by DPV and chronopotentiometry (CP), exploiting the changes of the electrical signals due the [Fe(CN)] redox probe, when SARS-CoV-2 SP binds to the aptamer immobilized on the electrode surface. Current density, in DPV, and square root of the transition time, in CP, varied linearly with the log[ SARS-CoV-2 SP], providing lower limits of detection (LOD) of 0.11 ng/mL and 37.8 ng/mL, respectively. The sensor displayed good selectivity, repeatability, and was tested in diluted human saliva, spiked with different SARS-CoV-2 SP concentrations, providing LODs of 0.167 ng/mL and 46.2 ng/mL for DPV and CP, respectively.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）即新冠病毒（COVID-19）疾病的增殖和传播已成为全球生物安全的一大威胁。因此，新冠病毒疾病的早期诊断对于抗击当前的感染传播至关重要。在本研究中，我们提出了一种基于适配体的灵活电化学传感器，用于快速、无标记检测SARS-CoV-2刺突蛋白（SP）。由涂有金纳米颗粒的多孔柔性碳布制成的平台，用于提高材料的导电性和电化学性能，该平台通过硫醇功能化DNA适配体与金形成S-Au键，以选择性识别SARS-CoV-2刺突蛋白。传感器制备的各个步骤之后采用了扫描电子显微镜、循环伏安法和差分脉冲伏安法（DPV）。所提出的平台显示出良好的机械稳定性，在不同角度弯曲时伏安响应变化可忽略不计。利用SARS-CoV-2刺突蛋白与固定在电极表面的适配体结合时，[Fe(CN)]氧化还原探针引起的电信号变化，通过DPV和计时电位法（CP）对SARS-CoV-2刺突蛋白进行定量分析。DPV中的电流密度和CP中的过渡时间平方根与log[ SARS-CoV-2刺突蛋白]呈线性变化，检测下限（LOD）分别为0.11 ng/mL和37.8 ng/mL。该传感器具有良好的选择性、重复性，并在添加了不同SARS-CoV-2刺突蛋白浓度的稀释人唾液中进行了测试，DPV和CP的LOD分别为0.167 ng/mL和46.2 ng/mL。
