AbstractA newly designed cholesterol‐based quinazoline system 1 has been synthesized. The gelation ability of the compound 1 has been examined in different solvents. It exhibits strong gelation with silver perchlorate in benzene and acts as excellent visual detector of Ag+ ions over a series of other metal ions examined. The compound 1 selectively detects Al3+ ion as well with significant fluorometric response and color change. The benzene gel of 1 exhibits good viscoelastic response. In rheological study, the values of G’ are observed to be 8 times higher than those of G’’ at any frequency which signify dominant elastic character of the gel. The mode of aggregation of 1 during gelation in the presence of Ag+ ions and the binding of Al3+ ion in solution are explained by several spectroscopic techniques such as UV‐vis, fluorescence, FTIR and NMR. Theoretical study further enlightens the observations. As application, Ag‐gel shows excellent ability to remove toxic dyes from water.