Angular‐Inertia Regulated Stable and Nanoscale Sensing of Single Molecules Using Nanopore‐In‐A‐Tube

• Published in: Advanced materials (Weinheim) Vol. 37; no. 2; pp. e2400018 - n/a
• Main Authors: Yang, Jianxin, Pan, Tianle, Liu, Tong, Mao, Chuanbin, Ho, Ho‐Pui, Yuan, Wu
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.01.2025; John Wiley and Sons Inc
• Subjects: angular inertia‐kinetics; Controllability; Decoupling; Electrokinetic effects; funnel‐shaped nanopores; Gold; Inertia; nanopore‐in‐a‐tube device; Photovoltaic effect; Polyethylene glycol; Signal detection; single‐molecule sensing; single‐molecule sensing; funnel‐shaped nanopores; angular inertia‐kinetics; nanopore‐in‐a‐tube device
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202400018

Nanopore is commonly used for high‐resolution, label‐free sensing, and analysis of single molecules. However, controlling the speed and trajectory of molecular translocation in nanopores remains challenging, hampering sensing accuracy. Here, the study proposes a nanopore‐in‐a‐tube (NIAT) device that enables decoupling of the current signal detection from molecular translocation and provides precise angular inertia‐kinetic translocation of single molecules through a nanopore, thus ensuring stable signal readout with high signal‐to‐noise ratio (SNR). Specifically, the funnel‐shaped silicon nanopore, fabricated at a 10‐nm resolution, is placed into a centrifugal tube. A light‐induced photovoltaic effect is utilized to achieve a counter‐balanced state of electrokinetic effects in the nanopore. By controlling the inertial angle and centrifugation speed, the angular inertial force is harnessed effectively for regulating the translocation process with high precision. Consequently, the speed and trajectory of the molecules are able to be adjusted in and around the nanopore, enabling controllable and high SNR current signals. Numerical simulation reveals the decisive role of inertial angle in achieving uniform translocation trajectories and enhancing analyte‐nanopore interactions. The performance of the device is validated by discriminating rigid Au nanoparticles with a 1.6‐nm size difference and differentiating a 1.3‐nm size difference and subtle stiffness variations in flexible polyethylene glycol molecules. The study develops a nanopore‐in‐a‐tube (NIAT) device that precisely regulates molecule translocation in a funnel‐shaped nanopore by controlling the inertial angle and centrifugation speed in a centrifuge. This ensures stable signal readout with a high signal‐to‐noise ratio, enabling nanoscale sensing of single molecules.