Journal: Advanced Science

Article Title: Accelerated Electron Transfer in Nanostructured Electrodes Improves the Sensitivity of Electrochemical Biosensors

doi: 10.1002/advs.202102495

Figure Lengend Snippet: A) Schematics of electrochemical aptamer sensors on planar (left) and nanoporous (right) electrodes. The structure‐switching aptamer, end‐labeled with a methylene blue (MB) reporter, is unfolded in the absence of its target, doxorubicin (DOX). This situates MB far from the electrode, yielding minimal signal. DOX binding induces aptamer folding, bringing MB close to the electrode and producing an increase in current. B) Scanning electron microscopy (SEM) images of the nanoporous electrode. Upper and lower panels show top and side views, with scale bars of 100 and 50 nm, respectively. C) Impact of pore size on signal gain. Bottom panels show SEM images of the various nanoporous electrodes. Error bars in the x ‐direction represent the standard deviation of different nanopores captured in the corresponding SEM images. Error bars in the y ‐direction represent the standard deviation of the signal gain of three replicates.

Article Snippet: Commercial Ag/AgCl reference electrodes and Pt wire counter electrodes were from CH Instruments.

Techniques: Labeling, Binding Assay, Electron Microscopy, Pore Size, Standard Deviation

Journal: Advanced Science

Article Title: Accelerated Electron Transfer in Nanostructured Electrodes Improves the Sensitivity of Electrochemical Biosensors

doi: 10.1002/advs.202102495

Figure Lengend Snippet: Conditions yielding maximum sensor signal gain, signal level, and LOD for nanoporous and planar electrodes. Signal gain and level measurements are for 10 × 10 −6 m DOX; enhancement ratio describes improved performance in each optimized metric for nanoporous versus planar sensors

Article Snippet: Commercial Ag/AgCl reference electrodes and Pt wire counter electrodes were from CH Instruments.

Techniques:

Journal: Advanced Science

Article Title: Accelerated Electron Transfer in Nanostructured Electrodes Improves the Sensitivity of Electrochemical Biosensors

doi: 10.1002/advs.202102495

Figure Lengend Snippet: A) Signal level and B) signal gain of electrochemical aptamer sensors employing nanoporous (red) and planar (blue) electrodes in the presence of 100 × 10 −9 m –100 × 10 −6 m DOX. Plots are averaged over three replicates. Error bars represent the standard deviation.

Article Snippet: Commercial Ag/AgCl reference electrodes and Pt wire counter electrodes were from CH Instruments.

Techniques: Standard Deviation

Journal: Advanced Science

Article Title: Accelerated Electron Transfer in Nanostructured Electrodes Improves the Sensitivity of Electrochemical Biosensors

doi: 10.1002/advs.202102495

Figure Lengend Snippet: Scheme of how the electric double layer (EDL) from a planar (left) and nanoporous electrode (right) affects electron transfer from a MB reporter (blue circle) tethered to the aptamer (green) before and after target (orange square) binding. During electrochemical measurement, the MB reporter interacts with the EDL (shaded blue region), where a closer distance between the reporter and the electrode surface leads to faster electron transfer. In the nanoporous electrode, the MB group experiences stronger electric fields. A and A’ represent the electrode surface and the maximum distance of MB from the electrode, respectively.

Article Snippet: Commercial Ag/AgCl reference electrodes and Pt wire counter electrodes were from CH Instruments.

Techniques: Binding Assay

Journal: Advanced Science

Article Title: Accelerated Electron Transfer in Nanostructured Electrodes Improves the Sensitivity of Electrochemical Biosensors

doi: 10.1002/advs.202102495

Figure Lengend Snippet: Simulations of screening for nanostructured electrode geometries with 100 mV applied. Top panels show the tested geometries, including A) semicircular pores of varying radius, and triangular pores of B) fixed height (20 nm) and varying width (w) or (C) fixed width (20 nm) and varying height (h). Bottom panels show electric potentials for a 10 nm cut line extending vertically from the deepest point in the structure (white dashed line in top panels).

Article Snippet: Commercial Ag/AgCl reference electrodes and Pt wire counter electrodes were from CH Instruments.

Techniques:

Journal: Advanced Science

Article Title: Accelerated Electron Transfer in Nanostructured Electrodes Improves the Sensitivity of Electrochemical Biosensors

doi: 10.1002/advs.202102495

Figure Lengend Snippet: A) Ionic strength affects the EDL configuration, which affects transduction between the MB reporter and the electrode. As the ionic strength of the solution increases, the Debye length ( λ D ) decreases. Calibration curves were generated by performing SWV on aptamer‐functionalized B) planar and C) nanoporous electrodes with samples spiked with varying concentrations of DOX in different dilutions of SSC buffer to assess the impact of ionic strength on signal gain. Datapoints are averaged over three replicates, and error bars show standard deviation.

Article Snippet: Commercial Ag/AgCl reference electrodes and Pt wire counter electrodes were from CH Instruments.

Techniques: Transduction, Generated, Standard Deviation

Journal: Advanced Science

Article Title: Accelerated Electron Transfer in Nanostructured Electrodes Improves the Sensitivity of Electrochemical Biosensors

doi: 10.1002/advs.202102495

Figure Lengend Snippet: A) Chronoamperograms of planar (blue) and nanoporous (red) electrode sensors with an electrode size of 500 × 500 µm 2 in the absence of DOX (log scale, negative values not shown). B) The decay time ( τ slow ) of both electrodes at various DOX concentrations. Error bars represent the confidence intervals of the curve fitting.

Article Snippet: Commercial Ag/AgCl reference electrodes and Pt wire counter electrodes were from CH Instruments.

Techniques: