(A)
Schematic representation of a high-density nanopore-electrode
array and cross section of an individual nanopore configuration with
functionalized silver particles captured by applying a voltage at
a gold-ring electrode present within the confined pore vs a Pt quasi-reference
counter electrode (QRCE). Simultaneously, SERS measurements are conducted
by illuminating from the top with 532 nm incident light. Reproduced
from Kim, J. Y.; Han, D.; Crouch, G. M.; Kwon, S. R.; Bohn, P. W. Anal. Chem.2019, 91 (7),
4568–4576 (ref (82)). Copyright 2019 American Chemical Society. (B) Schematic depiction
of ICR sensing of serotonin with aptamer-functionalized nanopipettes.
Upon binding of serotonin, the aptamers undergo a conformational rearrangement
that leads to a change in the ionic flux through the nanopipette,
altering the ICR. Reproduced from Nakatsuka, N.; Failletaz, A.; Eggemann,
D.; Forro, C.; Voros, J.; Momotenko, D. Anal. Chem. 2021, 93 (8), 4033–4041 (ref (85)). Copyright 2021 American
Chemical Society. (C) Schematic of a double-barrel nanopipette utilized
as an extended field-effect transistor sensor for selective detection
and controlled protein transport. Reproduced from Selective Sensing
of Proteins Using Aptamer Functionalized Nanopore Extended Field-Effect
Transistors, Ren, R.; Wang, X.; Cai, S.; Zhang, Y.; Korchev, Y.; Ivanov,
A. P.; Edel, J. B. Small Methods2020, Vol. 4, Issue 11 (ref (91)) under CC-BY 4.0 license. (D) Example representation of
a wireless nanopore electrode utilized for nanoconfined electrochemical
sensing of silver nanoparticles collisions, supporting simultaneous
Faradaic and capacitive responses. Reproduced from Yu, R. J.; Xu,
S. W.; Paul, S.; Ying, Y. L.; Cui, L. F.; Daiguji, H.; Hsu, W. L.;
Long, Y. T. ACS Sens.2021, 6 (2), 335–339 (ref (93)). Copyright 2021 American Chemical Society.