Rhodopsin-Like Ionic Gate Fabricated with Graphene Oxide and Isomeric DNA Switch for Efficient Photocontrol of Ion Transport

Abstract

Rhodopsin, composed of opsin and isomeric retinal, acts as the primary photoreceptor by converting light into electric signals. Inspired by rhodopsin, we have fabricated a light-regulated ionic gate on the basis of the design of a graphene oxide (GO)-biomimetic DNA-nanochannel architecture. In this design, photoswitchable azobenzene (Azo)-DNA is introduced to the surface of porous anodic alumina (PAA) membrane. With modulation of the interaction between the GO blocker and Azo-DNA via flexibly regulating trans and cis states of Azo under the irradiation of visible and ultraviolet light, alternatively, the ionic gate is switched between ON and OFF states. This newly constructed ionic gate can possess high efficiency for the control of ion transport because of the high blocking property of GO and the rather tiny path within the barrier layer which are both first employed to fabricate ionic gate. We anticipate that this rhodopsin-like ionic gate may provide a new model and method for the investigation of ion channel, ion function, and ion quantity. In addition, because of the advantages of simple fabrication, good biocompatibility, and universality, this bioinspired system may have potential applications as optical sensors, in photoelectric transformation, and in controllable drug delivery.

Bioinspired Design of Graphene‐Based Materials

“…For instance, taking advantage of the cis-trans isomerization of Azo-DNA under UV (cis) or visible (trans) light, the stronger or weaker interactions of the molecule with GO causes ion transport to be blocked or allowed, respectively. [83] The nose is a chemical "detection system to sense any molecule in the gas or liquid state," at concentrations as low as a few parts per trillion. [84] Mammals detect odorant stimuli by binding the molecules to receptor proteins on the olfactory cilia, which triggers intracellular signal cascades and spiking of the chemosensory neurons based on the strength, duration, and quality of the stimuli.…”

Bio-inspired nanochannels: fabrication, modification and bioanalytical applications

“…Xia课题组 [24] 首次发现, 在PAA的障碍层 . 首先, 通过化学偶联的方式将探针单链 DNA (ssDNA)固定在离子通道外表面, 当引入目标mi-图 12 (a) 凝血酶适配体功能化的纳米通道-离子通道器件在不同溶液pH下机理 [106] ; (b) 纳米通道-离子通道杂交结构表面修 饰和micro RNA检测原理 [107] ; (c) 基于GO与偶氮DNA修饰的PAA设计的光响应纳米流体装置 [108] ; (d) CTCs捕获和释放过程的 原理图 [110] (网络版彩图) [109,110] . 通过适配 体-CTCs的识别, 选择性地捕获溶液中的CTCs (图12 (d)) [110] .…”

“…(b) Illustration of surface modification and microRNA detection on the nanochannel-ionchannel hybrid[107]. (c) Light-responsive nanofluidic device designed based on GO and azo-DNA modified PAA[108]. (d) Schematic demonstration of the CTCs capture and release process[110] (color online).…”

Facile optimization of hierarchical topography and chemistry on magnetically active graphene oxide nanosheets

“…Optimization of necessary topography and chemistry in two dimensional (2D) graphene oxide (GO) nanosheets remains instrumental for achieving diverse and important properties in synthesized materials having impactful signicance in practical settings. [1][2][3][4][5] Inspired by these diverse and rational uses of GO-nanosheets, here, a facile and robust chemical approach has been unprecedentedly introduced for optimizing both the hierarchical topography and desired chemistry in the available space (in the order of mm) of 2D GO nanosheets. Interestingly, the co-optimization of appropriate hierarchical topography and low surface energy chemistry on macro-scale (porous/featureless) objects (that are visible with the naked eye) is imperative for achieving bioinspired extreme liquid wettability.…”