Gated MoS2/SiN nanochannel for tunable ion transport and protein translocation

Ionic transport in nanofluidic channels holds great promise for applications such as single-molecule analysis, molecular manipulation, and energy harvesting. However, achieving precise control over ion transport remains a major challenge. In this work, we introduce a MoS2/SiN hybrid nanochannel architecture that enables electrical tuning of ionic transport via external gating, and we examine its potential for osmotic power generation and single-molecule detection. To fabricate the channels, we employed a combined focused ion beam (FIB) milling and dry transfer method, producing sub-10 nm thick structures while preserving the structural integrity and electronic properties of MoS2—essential for reliable surface charge modulation. We first investigated how the gate voltage influences ionic conductance, finding evidence of gate-dependent modulation of ion selectivity under different bias polarities, with a rectification ratio of up to 10 in 1 M KCl. Next, by applying a salt concentration gradient across the nanochannels, we demonstrated the feasibility of this platform for osmotic energy generation, achieving a maximum power output of ~ 18 pW from a single channel and ~ 144 pW and ~ 337 pW from 10-channels and 20-channels array, corresponding to a high power density of ~ 18 kW/m². Finally, we tested the system for single-molecule sensing, showing that linearized bovine serum albumin (BSA) produced translocation signals with notably long dwell times exceeding previous reports. Together, these results highlight gated MoS2/SiN nanochannels as a promising platform for tunable nanofluidics, with potential applications in controlled molecular transport and energy generation from osmotic gradients.