Endowing hexaphenylsilole with chemical sensory and biological probing properties by attaching amino pendants to the silolyl core

Hexaphenylsilole (HPS) was functionalized by two amino (A2) groups, giving a new silole derivative of 1,1-bis[4-(diethylaminomethyl)phenyl]-2,3,4,5-tetraphenylsilole (A2HPS) that is capable of detecting explosives, biomacromolecules and pH changes. A2HPS is nonemissive when molecularly dissolved but becomes highly luminescent when aggregated. The emission of its nanoaggregates is quenched by picric acid with a high Ksv value (∼1.7 × 105 M−1). A2HPS can dissolve in acidic aqueous media, due to the transformation of its amino groups to ammonium-salts. The resultant nonemissive aqueous solution is turned on by increasing its pH value or adding protein or DNA.