Trinuclear complex [Au2Ag(dppmaphen)2(CN)2]PF6 photoluminesces on exposure to low molecular weight alcohols. This emission is likely due to C-Hπ interactions between the analyte and -PPh2 group, that inhibits non-radiative relaxation of the photoexcited state. Photoluminescene was quenched by removing the analyte under a stream of N2 or replacing it with H2O. This on/off switching was clearly visible, relatively rapid and recyclable.