Journal: ACS Nano

Article Title: Controlled Sensing of User-Defined Aptamer-Based Targets Using Scanning Ionic Conductance Spectroscopy

doi: 10.1021/acsnano.4c18509

Figure Lengend Snippet: Verification and repeated measurement on sample. (A) Illustration of the scanning pathway taken by the SICS. The sample is scanned for multiple molecules by rastering the pipette across the sample in a snake-like manner (first along an X direction (continuously scan) and then a shift in Y , stepwise 1 μm). (B) Histogram of data collected for three different samples compared with control experiments in free translocation. We achieve significantly higher rates of detection with our SICS based approach when compared to free translocation experiments. (C) Contour plots of the integrated current blockade vs height of the signal from 3 different capillary measurements ( N cap1 = 23, N cap2 = 72, N cap3 = 39). We observe 2 different clusterings of the signal which we associate to either the presence of the aptamer only or thrombin bound conditions. Insertion: Each sensed molecule was characterized by measuring its height and blockage area.

Article Snippet: Quartz capillaries (Hilgenberg GmbH, length 70 mm, outside diameter 0.5 mm, and inside diameter 0.2 mm) were pulled by using a CO2 laser puller (P-2000, Sutter Instruments) with the following protocol: Heat = 580, Fil = 0, Vel = 15, Del = 170, Pul = 0; Heat = 570, Fil = 0, Vel = 15, Del= 170, Pul = 200.

Techniques: Transferring, Control, Translocation Assay

Journal: ACS Nano

Article Title: Controlled Sensing of User-Defined Aptamer-Based Targets Using Scanning Ionic Conductance Spectroscopy

doi: 10.1021/acsnano.4c18509

Figure Lengend Snippet: Multiplex DNA carrier experiments. (A) Design of a DNA carrier with 2 gaps and attachment to the surface. (B) Examples of measurements done on DNA with 2 gaps and sample current traces showing 3 different cases. Case 1 : both gaps containing aptamers, in gap 1 is TBA1, in gap 2 is TBA2 Case 2 : both gaps containing aptamers but only one site (TBA2) contains an attached protein. Case 3 : both gaps containing aptamers and both sites with attached proteins. (C) Density function plot of repeated measurements with the same capillary ( N = 6). Top: Density function plot of the molecules that are thrombin bound only in gap 1 (TBA1). Bottom: Density function plot of the molecules that have thrombin-bound in both gaps 1 and 2. (D) Histogram of repeated measurements showing percentages of events sorted by the 5 different cases ( N = 3). (E) Aggregated data from repeated experiments. Overall binding percentages as detected by the SICS approach is shown in the 2 different cases (aptamer and aptamer bound to the thrombin). We achieve a much higher detection rate with the 2 gap system.

Article Snippet: Quartz capillaries (Hilgenberg GmbH, length 70 mm, outside diameter 0.5 mm, and inside diameter 0.2 mm) were pulled by using a CO2 laser puller (P-2000, Sutter Instruments) with the following protocol: Heat = 580, Fil = 0, Vel = 15, Del = 170, Pul = 0; Heat = 570, Fil = 0, Vel = 15, Del= 170, Pul = 200.

Techniques: Multiplex Assay, Binding Assay