Fig. 4.

Detection of SARS-CoV-2 pseudovirus. A) Representative Nyquist plots from measurements of a bare gold electrode (black squares), electrode after functionalization with S1Ab (red circles), and S1Ab-functionalized electrode after incubation in solution containing 2 × 10⁷/mL SΔ19-VSV^GFPΔG pseudovirus particles (green triangles). B. Corresponding R_ct values averaged over 3–5 repetitions. C. Comparison of %ΔR_ct using SΔ19-VSV^GFPΔG vs. VSVΔG-G. Red bars present %ΔR_ct immediately after incubation with either SΔ19-VSV^GFPΔG or VSVΔG-G and blue bars show the same electrodes after 15 min of subtle shaking at room temperature; D) Dependence of %ΔR_ct on SΔ19-VSV^GFPΔG concentration. Data represent the average of three independent experiments (6–8 repetitions each). Error bars represent ±SD. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)