Abstract：
The frequent emergence of variants of concern (VOC) of SARS-CoV-2 necessitates a sensitive and all-inclusive detection platform that remains viable despite the virus mutations. In this context, we targeted the receptor-binding domain (RBD) of glycoprotein (S-protein) of all VOC and constructed a consensus RBD (cRBD) based on the conserved amino acids. Then, we selected a high-affinity ssDNA novel aptamer specific for the cRBD by an in silico approach. The selected aptamer is utilized to fabricate a photonic crystal (PC)-decorated aptasensor (APC-sensor), which consists of polystyrene nanoparticles polymerized within a polyacrylamide hydrogel. cRBD-responsive ssDNA aptamers are crosslinked in the hydrogel network, which selectively bind to the cRBD and SARS-CoV-2 in saliva samples. The binding response can be visually monitored by swelling of the hydrogel and color generation by diffraction of light from PCs and can be quantified by the diffraction ring diameter or a spectrometer. The sensor delivers a LOD of 12.7 ± 0.55 ng mL-1 for the cRBD and 3 ± 18.8 cells mL-1 for SARS-CoV-2 in saliva samples, with a rapid response of 5 min. The sensor can be stored and regenerated without loss of activity. It can be utilized as a point-of-care testing (POCT) for SARS-CoV-2 diagnosis.
摘要：
SARS-CoV-2的关注变体（VOC）的频繁出现需要一个灵敏且包罗万象的检测平台，尽管病毒突变，该平台仍然可行。在这种情况下，我们靶向所有VOC的糖蛋白(S蛋白)的受体结合域(RBD),并基于保守氨基酸构建了共有RBD(cRBD).然后，我们通过计算机模拟方法选择了对cRBD具有特异性的高亲和力ssDNA新型适体。选择的适体用于制造光子晶体（PC）装饰的aptasensor（APC传感器），它由聚丙烯酰胺水凝胶中聚合的聚苯乙烯纳米颗粒组成。cRBD响应的ssDNA适体在水凝胶网络中交联，选择性结合唾液样品中的cRBD和SARS-CoV-2。结合响应可以通过水凝胶的溶胀和通过来自PC的光的衍射的颜色产生来视觉监测,并且可以通过衍射环直径或光谱仪来定量。该传感器在唾液样本中，cRBD的LOD为12.7±0.55ngmL-1，SARS-CoV-2的LOD为3±18.8细胞mL-1，具有5分钟的快速反应。传感器可以在没有活性损失的情况下存储和再生。它可以用作SARS-CoV-2诊断的即时测试（POCT）。
