Phenylboronic acid-functionalized vertically ordered mesoporous silica films for selective electrochemical determination of fluoride ion in tap water.

The selective electrochemical determination of fluoride is reported by phenylboronic acid-functionalized vertically ordered mesoporous silica film attached to the indium tin oxide electrode, designed as PBA-VMSF/ITO. Fluoride ion can selectively bind to phenylboronic acid to generate boronate anions, leading to negative charges inside the ultrasmall nanochannel of VMSF and ultimately rejecting the access of potassium ferricyanide ions to the electrode surface. By recording the reduced electrochemical signal of potassium ferricyanide, determination of fluoride ion in aqueous solution was achieved with a fast response, wide response range, and high selectivity. Furthermore, with the specific recognition of PBA and anti-fouling ability of VMSF, the PBA-VMSF/ITO sensor has been successfully used to detect fluoride ion in tap water.