School of Engineering, University of California, Santa Cruz, CA 95064;
School of Engineering, University of California, Santa Cruz, CA 95064.
Proc Natl Acad Sci U S A. 2021 May 18;118(20). doi: 10.1073/pnas.2103480118.
The urgency for the development of a sensitive, specific, and rapid point-of-care diagnostic test has deepened during the ongoing COVID-19 pandemic. Here, we introduce an ultrasensitive chip-based antigen test with single protein biomarker sensitivity for the differentiated detection of both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A antigens in nasopharyngeal swab samples at diagnostically relevant concentrations. The single-antigen assay is enabled by synthesizing a brightly fluorescent reporter probe, which is incorporated into a bead-based solid-phase extraction assay centered on an antibody sandwich protocol for the capture of target antigens. After optimization of the probe release for detection using ultraviolet light, the full assay is validated with both SARS-CoV-2 and influenza A antigens from clinical nasopharyngeal swab samples (PCR-negative spiked with target antigens). Spectrally multiplexed detection of both targets is implemented by multispot excitation on a multimode interference waveguide platform, and detection at 30 ng/mL with single-antigen sensitivity is reported.
在当前 COVID-19 大流行期间，开发一种灵敏、特异和快速的即时诊断检测方法的紧迫性日益加深。在这里，我们介绍了一种基于芯片的超灵敏抗原检测方法，该方法具有单个蛋白质生物标志物的灵敏度，可在诊断相关浓度下区分检测鼻咽拭子样本中的严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）和甲型流感病毒抗原。通过合成一种荧光强度高的报告探针来实现单抗原检测，该探针被整合到基于抗体夹心方案的基于珠的固相萃取测定法中，用于捕获目标抗原。在用紫外线检测进行探针释放优化后，使用来自临床鼻咽拭子样本（用目标抗原 PCR 阴性加标）的 SARS-CoV-2 和甲型流感病毒抗原对整个测定法进行了验证。通过在多模干涉波导平台上进行多斑点激发来实现对两种靶标的光谱多重检测，并报告在 30ng/mL 时具有单抗原灵敏度的检测。
