Lawrence Livermore National Laboratory



Steven Buchsbaum

Overview

The interaction between neighboring excitable nanopores and the resulting propagation of signals is the cornerstone of many life-sustaining processes and has immense potential for future nanotechnology and biomedical applications. This project produced the first synthetic platform of functionalized, solid-state nanopores in which signal propagation can be induced and studied at the individual nanopore level. We demonstrated key, single-pore attributes required to enable truly biomimetic solid-state multi-pore systems: 1) transport selectivity between sodium and potassium cations achieved through chemical modification of the pore walls, and 2) voltage- and ion-concentration-sensitive transport modulated by DNA attached to the entrance of an asymmetrically shaped pore.

We used focused ion-beam technology to develop a pore fabrication method that provides control over the position, size, and surface chemistry of each pore in a multi-pore platform and used these capabilities to fabricate two pores near each other. We demonstrated that the transport through a pore designed to be initially open can induce a change in conductance of a neighboring, initially closed pore that has been chemically modified to be ion concentration responsive. This successful demonstration of a signal passed from one man-made pore to another is an important step towards the integration of nanopore technology into more complex multi-component systems.

Impact on Mission

Our foundational work strengthened Lawrence Livermore National Laboratory's core competencies in bioengineering and bioscience and helped establish Livermore as a world leader in the nanopore field by demonstrating, for the first time, signal propagation in multiple-pore systems made of artificial, excitable ion channels. Our results advance The Department of Energy's goal to bridge fundamental science with technology innovation, particularly new approaches to delivering drug therapies and to treating medical disorders resulting from failed or impeded signaling.

Publications, Presentations, Etc.

Acar, E., et al. 2019. "Biomimetic Potassium-Selective Nanopores." Science Advances 5 (2):eaav2568. doi: 10.1126/sciadv.aav2568. LLNL-JRNL-760930.

——— . 2019. "A Robust Mechanism to Render Artificial Nanopores Potassium Ion Selective." 63rd Biophysical Society Annual Meeting, Baltimore, MD, March 2019. LLNL-POST-795958.

Buchsbaum, S., et al. 2018. "Stimuli Responsive Nanfluidic Platforms." Molecular Foundry Users Meeting, Lawrence Berkeley National Laboratory, Berkeley, CA, August 2018. LLNL-POST-756479.

——— . 2019. "Biomimetic, Voltage-Sensitive Nanopores With Local Control Over Pore Position, Size and Surface Chemistry." 63rd Biophysical Society Annual Meeting, Baltimore, MD, March 2019. LLNL-POST-768666.