Nanopore-based detection techniques, with a wide range of transport properties, exhibit impressive selectivity and sensitivity for analytes. To expand the application of nanoporous sensors, real-time and fast detection of targets, all within a portable device, is highly desired for nanopore-based sensors. In addition, to improve the accuracy of the output signal, more appropriate readout methods also need to be explored. In this manuscript, we describe a nanopore-based electrode, regarded as NAC-P6-PC@AuE, prepared by coupling a pillararene-based nanoporous membrane with an electrochemical impedance measurement method. The fabricated device is demonstrated by exposing pillararene-based receptors to trace amounts of pesticide molecules. NAC-P6-PC@AuE devices exhibit distinguished selectivity to quinotrione, as well as the ability to quantify quinotrione with a limit of quantitation (LOQ) of 10 nM. The mechanism that allows sensing was verified using finite-element simulations and may be explained as host−guest-induced surface charge shielding, which influences the electrochemical response of probe molecules. The applications of this nanopore-based electrode may be extended toward other target molecules by decorating the nanopore surfaces with specifically chosen receptors.

No abstract

No abstract

Chiral-specific assembly is involved in many biochemical processes, such as DNA hybridization, protein adhesion, and sugar recognition. However, the signals of chiral interaction are usually very weak, and it is difficult to investigate the enantioselective behaviors. Therefore, it is necessary to construct the functional materials to regulate the selective behaviors of protein droplets via weak chiral interaction, which is also significant for the biological process of protein adhesive behaviors and proteinic drug delivery. Here, S-and Ramino alcohol derivative of calix[4]arene enantiomers (R/S-AC4) were synthesized and modified onto Au-surfaces to fabricate the enantiomer's materials and investigate the chiral selective adhesion of protein droplets. Through the experiment of fluorescence titration and molecular docking simulation, bovine serum albumin (BSA) showed the stronger interaction with R-amino alcoholcalix[4]arene than S-amino alcohol-calix [4]arene on the molecular level. Notably, the sliding angle showed that the droplet of BSA selectively adhered to the Ramino alcohol-calix[4]arene-modified surface, while it released rapidly from S-amino alcohol-calix[4]arene-modified surface by virtue of chiral selectivity. This result not only provides an easy and convenient model to regulate the selective adhesion and release of protein from chemical view, but also realizes the signal transduction through the weak chiral interaction.