Covalent Organic Frameworks as Selective AC-Impedimetric Sensor Materials

Covalent Organic Frameworks (COFs) films hold much promise in material research due to the breadth of properties they possess. They are inherently porous, and clever synthesis can construct nanosheets of almost any pore size or functionalization. Consequently, the have the inherent ability to be species-selective in several ways, such as size, chemical affinity, and tunable physisorption. This is excellent for sensing, but most COFs have the drawback of being insulative, thus making it challenging to form them into direct sensors. Various approaches have been used in literature, but in this talk we will discuss building upon a novel real-time impedance spectroscopy approach that can be sensitive to femtofarad level changes in capacitance to observe changes in permittivity of the COF film as analytes adsorb to the COF directly. Practical challenges and limitations as well as comparisons to other techniques will be discussed.