Figure 4.
Sensitivity and dynamic range of the assay for the detection of tdEVs. (a) Anodic cyclic voltammograms recorded at the anode for tdEV samples with concentrations ranging from 10 to 106 tdEVs per μL. (b) Associated calibration curve (based on the limiting currents recorded at 0.6 V vs Ag/AgCl) revealing a dynamic range spanning at least 6 orders of magnitude (number of devices, n = 3). The horizontal dotted line depicts the background level plus three times the standard deviation (SD) of the redox current; from this horizontal line and the calibration curve, a theoretical LOD as low as 5 tdEVs/μL is found. (Conditions: 1 mM pAPP solution in PBS (pH 7.4); scan rate of 50 mV/s.)