Smart DNA Hydrogel Integrated Nanochannels with High Ion Flux and Adjustable Selective Ionic Transport

Abstract

Nanochannels based on smart DNA hydrogels as stimulus-responsive architecture are presented for the first time. In contrast to other responsive molecules existing in the nanochannel in monolayer configurations, the DNA hydrogels are three-dimensional networks with space negative charges, the ion flux and rectification ratio are significantly enhanced. Upon cyclic treatment with K ions and crown ether, the DNA hydrogel states could be reversibly switched between less stiff and stiff networks, providing the gating mechanism of the nanochannel. Based on the architecture of DNA hydrogels and pH stimulus, cation or anion transport direction could be precisely controlled and multiple gating features are achieved. Meanwhile, G-quadruplex DNA in the hydrogels might be replaced by other stimulus-responsive DNA molecules, peptides, or proteins, and thus this work opens a new route for improving the functionalities of nanochannel by intelligent hydrogels.

Biomolecule‐Functionalized Solid‐State Ion Nanochannels/Nanopores: Features and Techniques

“…Wu et al constructed the 3D smart DNA hydrogels integrated in the tip side of conical and cigar‐sharp nanochannels. In the asymmetric nanochannels, the 3D DNA hydrogels brought several advantages: high rectification ratio, high ion fluxes, and controllable ionic transport direction . In one word, the signal amplification with DNA superstructures in nanochannels/nanopores relies on the programmable base pairing, which is the characteristic of DNA or the analogs.…”

“…Thereby, it is facile to immobilize the biomolecules with sulfur‐containing groups onto the nanochannels/nanopores surface and inner wall covered by Au plating. Generally, the Au plating is deposited by sputtering or electrochemical method . As shown in Figure a,b, the Au plating was depositing on the inner wall of the conical PET nanochannels and the AAO nanochannels.…”

“…As shown in Figure a,b, the Au plating was depositing on the inner wall of the conical PET nanochannels and the AAO nanochannels. [73a,76] Apparently, the original COOH groups on the inner wall of the PET nanochannels and the OH groups on the inner wall of the AAO nanochannels were covered. And the subsequent immobilization of the amino‐DNA was implemented on the Au plating by the Au‐S bonding, followed the hybridization for the DNA superstructures.…”

“…a) The conical PET nanochannel covered by Au coating, followed by DNA functionalization. Reproduced with permission . Copyright 2018, Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim.…”

“…Generally, the Au plating is deposited by sputtering or electrochemical method. [76] As shown in Figure 15a,b, the Au plating was depositing on the inner wall of the conical PET nanochannels and the AAO nanochannels. [73a,76] Apparently, the original COOH groups on the inner wall of the PET nanochannels and the OH groups on the inner wall of the AAO nanochannels were covered.…”