Tetrazine-functionalized and vertically-aligned mesoporous silica films with electrochemical activity and fluorescence properties

In spite of their attractive physico-chemical properties making them very promising in the field of functional molecular materials, s-tetrazine derivatives remain underexploited in practical devices mainly because their immobilization in a stable form maintaining all their features is still challenging. Here, we show that combining a `click chemistry azide/alkyne' approach with an electrochemically-assisted self-assembly (EASA) method, which is likely to generate azide-functionalized and vertically-aligned mesoporous silica films, and further derivatization of the ordered mesoporous material with propargyl-tetrazine via a soft Huisgen coupling reaction, enable one to reach this goal. The resulting tetrazine-functionalized films formed onto transparent indium-tin oxide (ITO) electrodes exhibit well-defined voltammetric signals, with peak currents proportional to the functionalization level and stable upon multiple potential scanning, as well as effective fluorescence properties as evidenced from fluorescence spectra with maximum emission at 555-560 nm.