[Show abstract][Hide abstract] ABSTRACT: Synthetic stimuli-gated nanodevices displaying intelligent ion transport properties similar to those observed in biological ion channels have attracted increasing interests for their wide potential applications in biosensors, nanofluidics, and energy conversions. Here, bioinspired asymmetric shaped nanodevices are reported that can exhibit symmetric and linear pH-gating ion transport features based on polyelectrolyte-asymmetric-functionalized asymmetric hourglass-shaped nanochannels. The pH-responsive polymer brushes grafted on the inner channel surface are acted as a gate that open and close in response to external pH changing to linearly and symmetrically regulate transmembrane ionic currents of the channel. A complete experimental characterization of the pH-dependent ion transport behaviors of the nanodevice and a comprehensive discussion of the experimental results in terms of theoretical simulation are also presented. Both experimental and theoretical data shown in this work demonstrate the feasibility of using the asymmetric chemical modification method to achieve symmetric pH gating behaviors inside the asymmetric nanochannels, and lay the foundation to build diverse stimuli-gated artificial asymmetric shaped ion channels with symmetric gating ion transport features.
[Show abstract][Hide abstract] ABSTRACT: Das Maßschneidern von Benetzbarkeit ist in den Oberflächenwissenschaften zwar wohlbekannt, aber dennoch ein hochinteressantes Thema, das bei der Lösung von größeren praktischen Problemen von enormem Interesse ist. In letzter Zeit wurden sowohl in der Natur als auch in Experimenten verschiedene superbenetzbare Systeme entdeckt. In diesem Aufsatz stellen wir drei Arten von Superbenetzbarkeit vor: dreidimensionale, zweidimensionale und eindimensionale Materialoberflächen. Durch das Kombinieren verschiedener Superbenetzbarkeiten lassen sich neue funktionale Grenzflächensysteme generieren und in Bauteile integrieren, die anschließend zur Lösung von aktuellen und zukünftigen Problemen im Zusammenhang mit Ressourcen, Energie, Umwelt und Gesundheit verwendet werden können.
[Show abstract][Hide abstract] ABSTRACT: Engineered wettability is a traditional, yet key issue in surface science and attracts tremendous interest in solving large-scale practical problems. Recently, different super-wettability systems have been discovered in both nature and experiments. In this Review we present three types of super-wettability, including the three-dimensional, two-dimensional, and one-dimensional material surfaces. By combining different super-wettabilities, novel interfacial functional systems could be generated and integrated into devices for use in tackling current and the future problems including resources, energy, environment, and health.
[Show abstract][Hide abstract] ABSTRACT: A stable system of enantioselectively recognising L-tryptophan based on ß-cyclodextrin-modified single nanochannel fabricated in a polyimide membrane was demonstrated, which is the first time to realize chiral recognition of essential amino acid with this systems.
Chemical Communications 01/2015; 51(15). DOI:10.1039/C4CC09577D · 6.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Bio-inspired nanochannels have emerged as an interface to mimic the functionalities of biological nanochannels. One remaining challenge is to develop double-gated nanochannels with dual response, which can regulate the ion transport direction by alternately opening and closing the two gates. In this work, a bio-inspired potassium and pH responsive double-gated nanosystem is presented, constructed through immobilizing C-quadruplex and G-quadruplex DNA molecules onto the top and bottom tip side of a cigar-shaped nanochannel, respectively. It is demonstrated that the two gates of the nanochannel can be opened and closed alternately/simultaneously. This phenomenon results from the attached DNA conformational transition caused by adjusting the concentrations of potassium ion and proton. This design is believed to be the first example of dual-responsive double-gated nanosystem, and paves a new way to investigate more intelligent bio-inspired nanofluidic system.
[Show abstract][Hide abstract] ABSTRACT: A highly efficient multi-stimuli-response ionic gate that can be activated separately or cooperatively by pH and UV light has been demonstrated by modifying the environmental stimuli-responsive molecule 8-hydroxypyrene-1,3,6-trisulfonate into a track-etched single conical nanochannel. Such a multi-response ionic gate can find applications in areas such as electronics, actuators, and biosensors.
[Show abstract][Hide abstract] ABSTRACT: A sensitive nano-device for D-glucose detection is prepared by modifying GOx enzymes into a single conical polymer nanochannel. Current-Voltage (I-V) characterization suggests that the nano-device could response to D-glucose with concentration down to 1 nM (10-9 mol L-1) rather than its enantiomer. Moreover, the nano-device behaves good reproducibility and specifity to D-glucose and will provide ideal candidate for commercialized non-invasive blood glucose meters in the future.
[Show abstract][Hide abstract] ABSTRACT: Inspired by biological asymmetric ion channels, new shape-tunable and pH-responsive asymmetric hourglass single nanochannel systems demonstrate unique ion-transport properties. It is found that the change in shape and pH cooperatively control the ion transport within the nanochannel ranging from asymmetric shape with asymmetric ion transport, to asymmetric shape with symmetric ion transport and symmetric shape with symmetric ion transport.
Small 09/2014; 11(7). DOI:10.1002/smll.201401677 · 8.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Inspired by the cooperative functions of the asymmetrical ion channels in living cells, a constructive bi-channel nanofluidic device that demonstrates the enhanced capability of multiple regulations over both the ion flux amount and the ionic rectification property is prepared. In this bi-channel system, the construction routes of the two asymmetric conical nanochannels provide a way to efficiently transform the nanodevice into four different functional working modes. In addition, the variation of external pH conditions leads the nanodevice to the uncharged, semi-charged and charged states, where the multistory ionic regulating function property is enhanced by the charged degree. This intelligent integration of the single functional nanochannels demonstrates a promising future for building more functional multi-channel integrated nanodevices as well as expands the functionalities of the bio-inspired smart nanochannels.
Small 02/2014; 10(4). DOI:10.1002/smll.201301647 · 8.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Biological nanochannels, such as ion channels and ion pumps, existing in cell membranes and intelligently controlling ions through the cell membrane serve as a big source of bio-inspiration for the scientists to build artificial functional nanochannels. In this Feature Article, a general strategy for the design and synthesis of bio-inspired smart single nanochannels is presented, and put into context with recent progress in constructing symmetric and asymmetric smart single polymer nanochannels with single/double artificial gates which can respond to single/multiple external stimuli, e.g., pH, ions, temperature, light, and molecules. This article is intended to utilize specific stimulus-dependent ionic transport properties inside the single nanochannel as an example to demonstrate the feasibility of the design strategy, and provide an overview of this fascinating research field.
Chemical Communications 09/2013; 49(86). DOI:10.1039/c3cc45526b · 6.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Bio-inspired artificial functional nanochannels for intelligent molecular and ionic transport control at the nanoscale have wide potential applications in nanofluidics, energy conversion, and biosensors. Although various smart passive ion transport properties of ion channels have been artificially realized, it is still hugely challenging to achieve high level intelligent ion transport features existed in biological ion pumps. Here we show a unique bio-inspired single ion pump based on a cooperative pH response double-gate nanochannel, whose gates could be opened and closed alternately/simultaneously under symmetric/asymmetric pH environments. Stimulating the double-gate nanochannel by continuous switching of the symmetric/asymmetric pH stimuli, the bio-inspired system systematically realized three key ionic transport features of biological ion pumps, including alternating gates ion pumping process under symmetric pH stimuli, transformation of the ion pump into ion channel under asymmetric pH stimuli, and fail-safe ion pumping feature under both symmetric and asymmetric pH stimuli. The ion pumping processes could well be reproduced under concentration gradient. Taking advantages of the extraordinary ionic transport functions of biological ion pumps, the bio-inspired ion pump should find widespread applicability in active transportation controlling smart nanofluidic devices, efficient energy conversions, and sea water desalinization, and open the way to design and develop novel bio-inspired intelligent artificial nanochannel materials.
Journal of the American Chemical Society 06/2013; 135(43). DOI:10.1021/ja4037669 · 12.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Inspired by living systems that have the inherent skill to convert solar energy into bioelectric signals with their light-driven cross-membrane proton pump, a photoelectric conversion system that can work in alkaline conditions based on photoinduced reversible pH changes by malachite green carbinol base and a smart gating hydroxide ion-driven nanofluidic channel is demonstrated. In this system, solar energy can be considered as the only source of cross-membrane proton motive force that induces diffusion potential and photocurrent flowing through the external circuit. The conversion performances are 0.00825% and 36%, which are calculated from the photoelectric conversion and Gibbs free energy diffusion, respectively. The results suggest that electric power generation and performance could be further optimized by selecting appropriate photosensitized molecules and enhancing the surface-charge density as well as adopting the appropriate channel size. This facile, cost-efficient, and environmentally friendly photoelectric conversion system has potential applications for future energy demands such as production of power for in vivo medical devices.
[Show abstract][Hide abstract] ABSTRACT: A simple biomimetic mercury(ii)-gated single nanochannel has been developed by incorporating a mercury(ii) responsive single stranded DNA (ssDNA) with thymine-thymine (T-T) bases into a single polymetic nanochannel.
Chemical Communications 06/2013; 49(91). DOI:10.1039/c3cc42748j · 6.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Both scientists and engineers are interested in the design andfabrication of synthetic nanofluidic architectures that mimic the gating functions of biological ion channels. The effort to build such structures requires interdisciplinary efforts at the intersection of chemistry, materials science, and nanotechnology. Biological ion channels and synthetic nanofluidic devices have some structural and chemical similarities, and therefore, they share some common features in regulating the traverse ionic flow. In the past decade, researchers have identified two asymmetric ion transport phenomena in synthetic nanofluidic structures, the rectified ionic current and the net diffusion current. The rectified ionic current is a diode-like current-voltage response that occurs when switching the voltage bias. This phenomenon indicates a preferential direction of transport in the nanofluidic system. The net diffusion current occurs as a direct product of charge selectivity and is generated from the asymmetric diffusion through charged nanofluidic channels. These new ion transport phenomena and the elaborate structures that occur in biology have inspired us to build functional nanofluidic devices for both fundamental research and practical applications. In this Account, we review our recent progress in the design and fabrication of biomimetic solid-state nanofluidic devices with asymmetric ion transport behavior. We demonstrate the origin of the rectified ionic current and the net diffusion current. We also identify several influential factors and discuss how to build these asymmetric features into nanofluidic systems by controlling (1) nanopore geometry, (2) surface charge distribution, (3) chemical composition, (4) channel wall wettability, (5) environmental pH, (6) electrolyte concentration gradient, and (7) ion mobility. In the case of the first four features, we build these asymmetric features directly into the nanofluidic structures. With the final three, we construct different environmental conditions in the electrolyte solutions on either side of the nanochannel. The novel and well-controlled nanofluidic phenomena have become the foundation for many promising applications, and we have highlighted several representative examples. Inspired by the electrogenic cell of the electric eel, we have demonstrated a proof-of-concept nanofluidic reverse electrodialysis system (NREDS) that converts salinity gradient energy into electricity by means of net diffusion current. We have also constructed chirality analysis systems into nanofluidic architectures and monitored these sensing events as the change in the degree of ionic current rectification. Moreover, we have developed a biohybrid nanosystem, in which we reconstituted the F0F1-ATPase on a liposome-coated, solid-state nanoporous membrane. By applying a transmembrane proton concentration gradient, the biohybrid nanodevice can synthesize ATP in vitro. These findings have improved our understanding of the asymmetric ion transport phenomena in synthetic nanofluidic systems and offer innovative insights into the design of functional nanofluidic devices.
Accounts of Chemical Research 05/2013; 46(12). DOI:10.1021/ar400024p · 22.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Through evolution, nature has arrived at what is optimal. Inspired by the biomaterials with special wettability, superhydrophobic materials have been well-investigated and -covered by several excellent reviews. The construction of superoleophobicity is more difficult than that of superhydrophobicity because the surface tension of oil or other organic liquids is lower than that of water. However, superoleophobic surfaces have drawn a great deal of attention for both fundamental research and practical applications in a variety of fields. In this contribution, we focus on recent research progress in the design, fabrication, and application of bio-inspired superoleophobic and smart surfaces, including superoleophobic–superhydrophobic surfaces, oleophobic–hydrophilic surfaces, underwater superoleophobic surfaces, and smart surfaces. Although the research of bio-inspired superoleophobicity is in its infancy, it is a rapidly growing and enormously promising field. The remaining challenges and future outlook of this field are also addressed. Multifunctional integration is a inherent characteristic for biological materials. Learning from nature has long been a source of bio-inspiration for scientists and engineers. Therefore, further cross-disciplinary cooperation is essential for the construction of multifunctional advanced superoleophobic surfaces through learning the optimized biological solutions from nature. We hope this review will provide some inspirations to the researchers in the field of material science, chemistry, physics, biology, and engineering.
[Show abstract][Hide abstract] ABSTRACT: There are many elaborate masterpieces exist in natural world. Learning from nature, people developed serial intelligent biomimetic devices. Biomimetic smart nanochannels received widespread attention for mimicking biological processes in bodies. Excellent stability, tailorable surface characteristics and nano-size effects rend polymer single nanochannel an ideal candidate for constructing sensitive and reproducible biosensors. Nanochannels are responsive for special analytes while appropriate recognition elements are modified in channels wall. In this review, we summarized recent works in contructing biosensors that are using polymer single nanochannels for detecting various analytes.
Chinese Science Bulletin 05/2013; 58(13). DOI:10.1007/s11434-013-5788-0 · 1.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An efficient and reversible ionic gating that can be activated by pH and light is demonstrated on page 6193 by Lei Jiang, Zhishan Bo, and co-workers, by modifying a malachite green derivative on the interior surface of an ion track-etched conical nanochannel. The switches between the OFF-state and the ON-state are dependent on the surface charge transition caused by the malachite green derivative, making it suitable for confined spaces. Such a dual-driven ionic gating could find applications in electronics, actuators, and biosensors.
[Show abstract][Hide abstract] ABSTRACT: A highly efficient and perfectly reversible ionic gate that can be activated by pH or UV light is demonstrated. Switching between the OFF state and the ON state is mainly dependent on the surface charge transition brought about by the malachite green derivative attached to the interior surface of an ion track-etched conical nanochannel, which makes it suitable for confined spaces. Applications in electronics, actuators, and biosensors can be foreseen.
[Show abstract][Hide abstract] ABSTRACT: Biological ion channels are able to control ion-transport processes precisely because of their intriguing properties, such as selectivity, rectification, and gating. Learning from nature, scientists have developed a promising system--solid-state single nanochannels--to mimic biological ion-transport properties. These nanochannels have many impressive properties, such as excess surface charge, making them selective; the ability to be produced or modified asymmetrically, endowing them with rectification; and chemical reactivity of the inner surface, imparting them with desired gating properties. Based on these unique characteristics, solid-state single nanochannels have been explored in various applications, such as sensing. In this context, we summarize recent developments of bioinspired solid-state single nanochannels with ion-transport properties that resemble their biological counterparts, including selectivity, rectification, and gating; their applications in sensing are also introduced briefly.