Highly Efficient Ionic Gating of Solid-State Nanosensors by the Reversible Interaction between Pillar[6]arene-AuNPs and Azobenzene.

By mimicking nature, various artificial nanofluidic platforms have been widely applied in a range of scientific fields. However, their low performance in terms of gating efficiency (<25) still hinders their practical applications. Herein, we present a highly efficient ionic gating nanosensor by fusing the merits of host-guest chemistry and Au nanoparticles (AuNPs). Based on this strategy, the pillar[6]arene (WP6)-functionalized AuNPs facilely regulated an azobenzene (AZO)-modified nanosensor with an excellent ion rectification ratio (∼22.2) and gating efficiency (∼89.5). More importantly, this gating nanosensor system also demonstrated promising stability and recyclability under conditions of alternative irradiation of visible and ultraviolet light. These excellent results would significantly help in expanding the utilization of artificial nanosensors for controllable drug delivery and biosensors.

Single Nanochannel Platform for Detecting Chiral Drugs.

Chiral drugs play an essential role in medical and biochemical systems, and thus enantioselective analysis of chiral molecules has become a central focus in chemical, biological, medical, and pharmaceutical research. The design of chiral drug-detecting systems is a long-term and challenging task. Here we report the use of a modification-free nanochannel method for enantioselective recognition of S-naproxen from R-naproxen using N-acetyl-l-cysteine-capped gold nanoparticles as a chiral selector. The chiral discrimination is based on a drug-induced nanoparticle diastereoselective aggregation mechanism that blocks ion transport through the nanochannel. We demonstrated that high S-Npx selectivity in both water and biological samples can be achieved. This simple method has potential applications as a general platform for the detection of chiral molecules.

Fabrication of a mercaptoacetic acid pillar[5]arene assembled nanochannel: a biomimetic gate for mercury poisoning.

Mercury ion binding blocks potassium ion channels, which leads to toxicity in vivo. It is challenging to design a simple and efficient artificial system to mimic the sophisticated biological process of mercury poisoning. Herein, based on biomimetic strategies, a tunable mercury(ii) ion-gate modulated by mercaptoacetic acid-pillar[5]arene (MAP5) is reported. By virtue of the unique design of the host-guest competition, potassium ion transport can actualize the reversible switching between "on" and "off" in the absence and presence of mercury ions. Moreover, the MAP5-immobilized nanochannel is highly effective at distinguishing Hg2+ from other metal ions and can be used to detect Hg2+ and act as an excellent and robust gate valve for developing integrated circuits and nanoelectronic logic devices. This study paves a new way for better understanding the physiological phenomenon of mercury toxicity and shows great promise for biomedical research.

Liquid Quantum Dots Constructed by Host-Guest Interaction.

It is a challenging task to construct nonionic liquid quantum dots (QDs) with highly optical perfermance. To address the problem, we make a new strategy to construct liquid QDs via host-guest interaction between ß-cyclodextrin and adamantane. Macroscopic fluidity and optical performance of liquid QDs can be controlled by the length of polyethylene glycol. The supramolecular compounds can make use of its excellent inclusion capacities to fasten flexible organic long-chain compounds on the surface of QDs to become nonionic. Compared with the ionic liquid QDs, nonionic liquid QDs based on supramolecular self-assembly offered a strong, fast host-guest interaction, avoiding multistep reactions that would be more favorable for maintaining the fluorescent property of QDs.