Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2024 May 21;96(20):8036-8055.
doi: 10.1021/acs.analchem.4c01406. Epub 2024 May 10.

Recent Developments in Single-Entity Electrochemistry

L Zhang  1 , O J Wahab  1 , A A Jallow  1 , Z J O'Dell  2 , T Pungsrisai  2 , S Sridhar  2 , K L Vernon  1 , K A Willets  2 , L A Baker  1
Affiliations
Review

Recent Developments in Single-Entity Electrochemistry

L Zhang et al. Anal Chem. .
No abstract available

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1
Figure 1
(a) Schematic diagram of the fabrication process of two particle nanoelectrode assemblies with the pick-and-drop method using a micromanipulator arm. (b) Plots showing the change in the ratio of the reduction current of Cu2O, Co3O4, and Cu2O+Co3O4 nanoelectrode assemblies at −0.35 V (vs RHE) compared to the 1st CV. (c) EDS mapping of Cu2O+Co3O4_CNE-1 (i), Cu2O+Co3O4_CNE-2 (ii), and Cu2O+Co3O4_CNE-3 (iii) before (top) and after (bottom) 5 CV cycles. Reproduced with permission from Single-entity Electrochemistry Unveils Dynamic Transformation during Tandem Catalysis of Cu2O and Co3O4 for Converting NO3– to NH3, Zhang, J.; He, W.; Quast, T.; Junqueira, J. R. C.; Saddeler, S.; Schulz, S.; Schuhmann, W. Angew. Chem. Int. Ed., Vol. 62, issue 8 (ref (27)). Copyright 2023 Wiley.
Figure 2
Figure 2
(a) Fabrication process of the platinized open carbon nanopipette modified with dibenzocyclooctyne (DBCO). Amperometric recordings obtained from (b) a single mitochondrion and (c) cytosol in a living MCF-7 cell using DBCO-modified nanopipettes before and after the addition of 16 μM phorbol 12-myristate 13-acetate (PMA). The applied potential was 0.6 V vs Ag/AgCl. (d) Analysis of the times to reach the maximal current from a single mitochondrion (n = 12) and cytosol (n = 10). (e) Analysis of the integrated charge from a single mitochondrion (n = 12) and cytosol stimulated by PMA (n = 10). Reproduced with permission from Click-Chemistry-Enabled Nanopipettes for the Capture and Dynamic Analysis of a Single Mitochondrion inside One Living Cell, Angew. Chem. Int. Ed., Vol 63, Issue 34 (ref (52)). Copyright 2023 Wiley.
Figure 3
Figure 3
(a) Schematic illustration of nonuniform current density at 10 μm disk UME which is highest at the rim, compared to 10 μm diameter and 50 nm width ring UME with uniform current density along the circumference. (b) Histogram of the step sizes for 476 current steps obtained from collisions of single polystyrene beads with the disk electrode. The red dashed curve represents the calculated probability density of step sizes. (c) Histogram of the step sizes for the same system using the 10 μm ring electrode. The x-axes in (b, c) show the step size per mille (‰) on a logarithmic scale. Reproduced from Moazzenzade, T.; Walstra, T.; Yang, X.; Huskens, J.; Lemay, S. G. Ring Ultramicroelectrodes for Current-Blockade Particle-Impact Electrochemistry. Anal. Chem.2022, 94 (28), 10168–10174 (ref (70)). Copyright 2022 American Chemical Society.
Figure 4
Figure 4
(a) Experimental procedures of the channel current measurements of DNA nanopores. The surface of a gold electrode was modified with thiol and PEG and then immersed in thiol-poly(dT)30 solution and DNA nanopore solution to immobilize the DNA nanopores on the electrode. (top) The DNA nanopore-tethered electrode was then inserted into the layered bath solution of an oil/lipid mixture and an aqueous solution forming a lipid bilayer when pushed through the oil/lipid and the aqueous solution. DNA nanopores are spontaneously inserted into the bilayer. (bottom) Channel currents through the nanopores were monitored by applying a potential between the gold and reference electrodes in the aqueous solution with a patch-clamp amplifier. (b, c) Recorded channel currents of DNA nanopores when using the (b-i) PEG 3000- and (b-ii) PEG 5000-modified gold electrodes. Under both conditions, step-like increases in the current were observed. Histograms of conductance calculated from the step-like signals when using the (c-i) PEG 3000- and (c-ii) PEG 5000-modified gold electrodes. Reproduced from Ikarashi, S.; Akai, H.; Koiwa, H.; Izawa, Y.; Takahashi, J.; Mabuchi, T.; Shoji, K. DNA Nanopore-Tethered Gold Needle Electrodes for Channel Current Recording. ACS Nano2023, 17 (11), 10598–10607 (ref (136)). Copyright 2023 American Chemical Society.
Figure 5
Figure 5
(a) Schematic of multiscale SECCM and the relative droplet size of the ensemble, individual particle, or subparticle measurement. Inset: the tip diameter (dtip) corresponds approximately to the meniscus diameter (dmeniscus) in hopping mode SECCM. (b) On the left, SEM images of (top) high density (HD) and (bottom) low density (LD) β-Co(OH)2 particle ensembles with an outline (dotted red) to show the droplet perimeter during SECCM measurements (dtip = 55 μm filled with 0.1 M KOH). On the right, LSVs of the (top) HD and (bottom) LD particle ensembles. (c) On top, LSVs (scan rate: 100 mV/s) of five single particles (solid color traces) and the mean response (dashed black trace) from nine particles. On the bottom, co-located AFM and SEM image of particle 1 (scale bar: 2 μm). SECCM was performed with dtip = 6 μm filled with 0.1 M KOH. (d) Topography (top) and current density (1.8 V vs RHE) maps (bottom) using a nanopipette probe with dtip ≈ 400 nm. Reproduced from Kang, M.; Bentley, C. L.; Mefford, J. T.; Chueh, W. C.; Unwin, P. R. Multiscale Analysis of Electrocatalytic Particle Activities: Linking Nanoscale Measurements and Ensemble Behavior. ACS Nano2023, 17 (21), 21493–21505 (ref (179)). Copyright 2023 American Chemical Society.
Figure 6
Figure 6
CLocK microscopy to optically monitor structural changes in the dissolution of a Au NR. (a) Schematic demonstrating how a birefringent calcite crystal separates light into an ordinary ray (o||) and a spatially displaced, orthogonally polarized extraordinary ray (e⊥). By matching the integration time of the camera and the rotation rate of the calcite crystal, an e⊥ ring encoding structural information is produced. (b) Simulated CLocK images of a (i) nanosphere and (ii–iv) NRs of various orientation. Scale bars = 1 μm. (c) Experimental CLocK images of a Au NR before (t = 0 s) and after (t = 840 s) dissolution showing the transformation from rod to sphere. (d) The normalized scattering intensity, (e) modulation depth, and (f) localized center-of-mass of the Au NR plotted as a function of dissolution time. Reproduced from Monaghan, J. W.; O’Dell, Z. J.; Sridhar, S.; Paranzino, B.; Sundaresan, V.; Willets, K. A. Calcite-Assisted Localization and Kinetics (CLocK) Microscopy. J. Phys. Chem. Lett.2022, 13 (45), 10527–10533 (ref (216)). Copyright 2022 American Chemical Society.
Figure 7
Figure 7
Integrated dark-field and fluorescence microscopy to measure the structure–function relationship in the electrocatalysis of ORR by Pt NPs. (a) Schematic of electrochemical setup and reaction at the Pt NP surface. (b) Fluorescence microscopy images captured at different applied potentials, along with correlated SEM images showing Pt NP position. Scale bar = 2 μm. (c) Ensemble voltammogram (blue) overlaid with average local pH changes (black) derived from single particle fluorescence intensity (green). (d) Change in observed fluorescence intensity (green line) and dark-field scattering intensity (black triangles) as the electrochemical potential is cycled for a particle experiencing enhanced electrochemical activity and (e) reduced electrochemical activity. Reproduced from Xie, R.-C.; Gao, J.; Wang, S.-C.; Li, H.; Wang, W. Optically Imaging In Situ Effects of Electrochemical Cycling on Single Nanoparticle Electrocatalysis. Analytical Chemistry2024, 96 (6), 2455–2463 (ref (243)). Copyright 2024 American Chemical Society.
Figure 8
Figure 8
(a) Schematic of SECCM coupled with interference reflective microscopy where the SECCM probe approaches from the top of the sample and the objective lens for illumination and collection of optical signals is located under the sample to monitor the electrodeposition of AgNPs. (b) Reconstructed image obtained from superlocalizing the optical signals, showing the displacement of the center-of-mass (color traces) of four different silver NPs during the electrodeposition process. The perimeter of the wetted area by the SECCM probe is shown in black. (c) The distribution of center-of-mass displacements of NPs (Δdc) obtained from optical features. (d) Proposed mechanism of AgNP growth mechanism based on the direction of the displacement of the centroid of the NPs. (e) Polar distribution of angles referring to the motion direction of the centroid of NPs relative to the center of the wetted area. Reproduced with permission from Optical Super-Localization of Single Nanoparticle Nucleation and Growth in Nanodroplets, Ciocci, P.; Valavanis, D.; Meloni, G. N.; Lemineur, J. F.; Unwin, P. R.; Kanoufi, F. ChemElectroChem, Vol 10, Issue 9 (ref (245)) Copyright 2023 Wiley.
Figure 9
Figure 9
(a) A full-system electrical circuit model for nano impact experiments consisting of the equivalent circuit of the nano impact electrochemical cell. (b) Full-system simulations of the nano impact spike using the model in (a) with r0,NP = 15 nm, [Cl–] = 15 mM, k = 2.77π, and different LPF bandwidths from 500 Hz to 5 kHz. (c) Schematic illustration of the different diffusion modes employed in the simulation, whereby the truncated spherical diffusion (k = 2.77π) is generally accepted as a representation of the diffusion field upon nanoparticle impact. (d) Individual nano impact spikes compared to the simulation predictions using different diffusion modes revealed a faster apparent rate of transformation than predicted using the conventional truncated spherical diffusion model with k = 2.77π. The 0.3 ms scale bar applies to all zoomed spikes. Reproduced from Kanokkanchana, K.; Tschulik, K. Electronic Circuit Simulations as a Tool to Understand Distorted Signals in Single-Entity Electrochemistry. J. Phys. Chem. Lett.2022, 13 (43), 10120–10125 (ref (255)). Copyright 2022 American Chemical Society.
See this image and copyright information in PMC

References

    1. Wang Y.; Shan X.; Tao N. Emerging tools for studying single entity electrochemistry. Faraday Discuss. 2016, 193, 9–39. 10.1039/C6FD00180G. - DOI - PubMed
    1. Mount A.; Kang M. Y.; Fermin D.; Albrecht T.; Gooding J.; Crooks R.; Tao N. J.; Schmickler W.; MacPherson J.; Chen S. L.; et al. Nanopores: general discussion. Faraday Discuss. 2016, 193, 507–531. 10.1039/C6FD90069K. - DOI - PubMed
    1. Gooding J.; Magnussen O.; Fermin D.; Crooks R.; Kanoufi F.; Schuhmann W.; Nichols R.; Schmickler W.; Tao N. J.; Chen S. L.; et al. From single cells to single molecules: general discussion. Faraday Discuss. 2016, 193, 141–170. 10.1039/C6FD90066F. - DOI - PubMed
    1. Crooks R. M. Concluding remarks: single entity electrochemistry one step at a time. Faraday Discuss. 2016, 193, 533–547. 10.1039/C6FD00203J. - DOI - PubMed
    1. Albrecht T.; MacPherson J.; Magnussen O.; Fermin D.; Crooks R.; Gooding J.; Hersbach T.; Kanoufi F.; Schuhmann W.; Bentley C.; et al. Electrochemistry of single nanoparticles: general discussion. Faraday Discuss. 2016, 193, 387–413. 10.1039/C6FD90068B. - DOI - PubMed