Investigation of Shielding Strategies to Mitigate Noise in Nanopore Recordings

Abstract

Shielding against electromagnetic interference (EMI), vibration, and mechanical noise is crucial for the reliable performance of sensitive electronics, especially in high-disturbance environments. While Faraday cages are ubiquitously used for this purpose, they are often implemented simply as metal boxes enclosing the measurement system without accounting for critical design factors such as skin depth. In this study, we investigated a range of factors to understand noise sources, coupling pathways, and systematic approaches for effective shielding beyond the common metal box approach, including the evaluation of power-line quality, grounding strategies for the Faraday cage, connectivity solutions to maintain Faraday cage integrity, and the relative positioning of the components in the measurement setup. Our findings have rendered the noise in the current measurements comparable to that of biological nanopores in the more ubiquitous 10 kHz lowpass filter setting. This low-noise floor has allowed us to detect DNA translocations under challenging low-electrolyte conditions (e.g., 10 mM KCl) using the highest lowpass filter setting of the Axopatch 200B (i.e., 100 kHz). Moreover, with necessary modifications, these findings were extended to the megahertz-level bandwidth regime, where sampling rates up to 10 MHz yielded extractable events with unfiltered traces. Although our findings broadly cater to solid-state nanopore (SSN) sensing, their applicability should extend beyond SSNs to other sensitive electronic systems.