ChemFET Anion Sensor Based on MOF Nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Supramolecular Chemistry

Background:

• Metal-organic frameworks (MOFs) are porous materials with significant internal surface area.
• The external surface chemistry of nanoparticles of metal-organic frameworks (nanoMOFs) is largely unexplored.
• Understanding nanoMOF external surfaces is crucial for developing new applications.

Purpose of the Study:

• To investigate the ion interactions with the external surfaces of Cu(1,2,3-triazolate)2 (Cu(TA)2) nanoparticles.
• To explore the potential of Cu(TA)2 nanoMOFs as chemical field effect transistor (ChemFET) anion sensors.
• To elucidate the principles governing anion selectivity in nanoMOF-based sensing.

Main Methods:

• Synthesized Cu(1,2,3-triazolate)2 (Cu(TA)2) nanoparticles.
• Studied ion interactions with nanoMOF external surfaces, observing Hofmeister-like behavior.
• Fabricated and tested Cu(TA)2 nanoMOFs in ChemFET devices for anion sensing.

Main Results:

• Observed that ion interactions with Cu(TA)2 nanoMOFs mimic Hofmeister effects seen in proteins and macromolecules.
• Demonstrated that Cu(TA)2 nanoMOF-based ChemFET sensors exhibit anion selectivity.
• Found that sensor sensitivity follows a Hofmeister trend, with highest sensitivity to perchlorate, iodide, and nitrate anions.

Conclusions:

• The external surface chemistry of nanoMOFs is critical and exhibits Hofmeister behavior.
• Cu(TA)2 nanoMOFs are effective anion sensors, with selectivity driven by supramolecular interactions.
• Pore-based supramolecular interactions are key for designing MOF-based sensing technologies, rather than localized interactions.