Potentiometric measurement of barbituric acid by integration of supramolecular receptors into ChemFETs

Evaluating impacts of bambusuril pocket size and sterics on anion binding trends using ChemFET sensors

Chemically-sensitive Field Effect Transistors (ChemFETs) are a useful tool to evaluate aqueous anion affinity of hydrophobic supramolecular scaffolds. More specifically, ChemFETs can be used to probe impacts of receptor modification to aqueous anion affinity. In this study, ChemFETs are used to evaluate the anion affinity of both dodeca-n-butyl bambus[6]uril and dodecabenzyl bambus[6]uril to assess steric effects in the chemical selectivity of the sensor membrane. The ChemFETs were evaluated through a series of common anions in the Hofmeister series in order to ascertain the difference in detection limit imparted by the specific functionalization of the bambus[6]uril macrocycles, which are quite sensitive to modest steric effects. Significant improvements to perchlorate and nitrate detection limits were observed via n-butyl bambusuril-containing sensor membranes over detection limits recorded with benzyl bambusuril sensors.

Host-Guest Systems on the Surface of Functionalized Superparamagnetic Iron Oxide Nanoparticles (SPIONs) Utilizing Hamilton Receptors and Cyanurate Derivative Molecules

The study of hydrogen bonding interactions at the level of functionalized nanoparticles remains highly challenging and poorly explored area. In this work, superparamagnetic iron oxide nanoparticles (SPIONs) were orthogonally functionalized using receptors bearing multiple hydrogen bonding motifs. Pristine SPIONs were modified by wet chemical processes with Hamilton receptors (hosts), or cyanurate‐guest molecules linked to phosphonic acid moieties for monolayer functionalization. The modified surfaces were fully characterized and the number of attached ligands on the surface were determined. The host‐guest interactions on the interface of modified SPIONs were investigated by using UV‐Vis spectroscopic titrations. Functionalized SPIONs demonstrated two to three magnitudes stronger binding affinities as compared to the related molecular interactions in solution due to synergistic effects on complex surface environment. Higher supramolecular binding ratios of host‐guest interactions on the modified surface were emerged. These studies provide fundamental insights into supramolecular complexations on the surface at solid‐liquid interface systems with applications in engineered nanomaterials, nano‐sensing devices, and drug delivery systems.