The synthesis of fluorescent probe for the selective ratiometric detection of Al(III) ions in pure aqueous buffered solutions and live cells is still a significant challenge. In the present study, we synthesized a new type of a fluorescent probe using an Al(III)-triggered self-assembly based on the dipeptide receptor and an aggregation-induced emission fluorophore. The fluorescent probe (1) showed a highly selective ratiometric response to Al(III) among 16 metal ions in aqueous buffered solution. The detection limit (145 nM, R2 = 0.999) for Al(III) ions was much lower than the maximum allowable level of Al(III) in drinking water demanded by EPA. DLS and TEM studies showed that the complex between 1 and Al(III) self-assembled to form nanoparticles, resulting in the enhancement of the emission at 600 nm and a concomitant decrease in the emission at 535 nm.