Electroanalysis in 2D-TiO2 Nanosheet Hosts: Electrolyte and Selectivity Effects in Ferroceneboronic Acid – Saccharide Binding

A 2D-TiO2 nanosheet material (as a film deposit of approximately 1 μm thickness on glassy carbon) is employed to host ferroceneboronic acid receptor molecules. It is suggested that the negative surface charge on 2D-TiO2 nanosheets allows weak binding of ferroceneboronic acid, which can then be employed to detect fluoride, glucose, or fructose. The nature of the aqueous electrolyte is shown to strongly affect the ferroceneboronic acid – host interaction. In the presence of di-sodium sulfate stable reversible voltammetric responses are observed. In the presence of fluoride loss of the ferroceneboronic acid occurs probably due to weakening of the boron-titanate interaction. For glucose and for fructose “bound” and “unbound” states of the ferroceneboronic acid are observed as long as fast square wave voltammetry is employed to capture the “bound” state before decomplexation can occur. It is shown that this kinetic selectivity is highly biassed towards fructose and essentially insensitive to glucose.