A smart AIEgen-functionalized surface with reversible modulation of fluorescence and wettability

Smart materials and surfaces with tunable functionalities are of great interest, especially for intelligent devices. However, achieving high sensitivity, fast response, simple operations and multi-response is still challenging. Here, a new strategy that utilizes the formation or dissociation of anion-pi(+) interactions to control the non-radiative decay of the molecules on the surface of the aggregation-induced emission (AIE) nanoparticles (NPs) is proposed for the first time. The ultrasensitive modulation of the fluorescence of the AIE NPs can be realized by a trace amount of acid. By using the AIE NPs to functionalize the silicon surface, a smart surface that possesses tunable fluorescence and wettability with an ultrafast response is obtained. Under acid vapor stimuli, multiple wetting status and wettability patterns can be precisely controlled on the AIE luminogen (AIEgen)-functionalized surface due to variation of the surface polarity. The introduced strategy is an innovative way of developing organic fluorescent NPs with tunable multi-functionalities, which can be used to develop ultrasensitive sensors and intelligent devices.