Synergistic Effect of Bio-Inspired Nanochannels: Hydrophilic DNA Probes at Inner Wall and Hydrophobic Coating at Outer Surface for Highly Sensitive Detection.

During the past few decades, bio-inspired nanochannels have been well developed and applied in biosensing, energy transfer, separation, and so on. Here, inspired by the synergistic effect of biological nanopores, biomimetic solid-state nanochannels with hydrophilic DNA probes at the inner wall (DNA@IW ) and hydrophobic coating at the outer surface (None@OS ) are designed. To demonstrate their prompted sensing properties, Hg and its specific probe are selected as target and hydrophilic DNA probes, respectively. Compared with the traditional solid-state nanochannels with hydrophilic probes distributed on both the inner wall and outer surface, the nanochannels with DNA@IW +None@OS significantly decrease the limit of detection (LOD) by 10 -fold. The obvious improvement of sensitivity (with LOD of 1 nM) is attributed to the synergistic effect: None@OS results in the nanochannel's effective diameter decrease and DNA@IW induces a specific sensing target. Meanwhile, nanomolar detection of Hg in human serum and in vivo fish muscle are achieved. Through molecular dynamics simulation, the synergistic effect can be confirmed by ion fluxes increasement; the relative carbon nanotube increases from 135.64% to 135.84%. This work improves the understanding of nanochannels' synergistic effect and provides a significant insight for nanochannels with improved sensitivity.