Supramolecular methods: utilising ChemFETs to evaluate aqueous anion affinity of hydrophobic receptors

ABSTRACT

The host–guest interaction and affinity of hydrophobic receptors towards aqueous anions can be evaluated by incorporating a receptor into a polymeric membrane and applying these membranes to FET-based sensing devices. A series of anions screened using these ChemFET (chemically sensitive field effect transistor) sensors based on different receptors can also provide a Hofmeister-like ordering of anions based on their respective detection limits. Although the general trends of selectivity coefficients often follow the Hofmeister Series, the specific anion affinity profiles are generally unique to each receptor and provide insight into receptor selectivity. In this methodspaper, we provide a detailed example of how our lab uses ChemFETs to evaluate host–guest interactions of hydrophobic host receptors with aqueous anions, and a detailed procedure for fabricating ChemFET sensor devices is presented along with selected case studies for readers interested in applying related ion recognition strategies in sensors of this type.

GRAPHICAL ABSTRACT

KEYWORDS:

• Anion sensing
• bambusuril
• ChemFETs
• Hofmeister series
• hydrogen bonding

Acknowledgments

The authors thank the NSF and NIH for generous support of various aspects of this research over the years in ChemFET sensors as well as a current NSF NRT training grant in “Molecular Probes and Sensors for Complex Environments” which has advanced progress in this research program as well (DGE-2022168). This work was also supported by the Air Force Institute of Technology (D.H.B.) and the University of Oregon.

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No potential conflict of interest was reported by the authors.

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Additional information

Funding

The work was supported by the National Science Foundation [DGE-2022168] and the Air Force Institute of Technology.