The aim of this study was to develop a new colorimetric and fluorometric chemosensor for Sn (II) & Al(III) detection in half aqueous medium. A new probe containing Bodipys, appended on phenolphthalein (PP-B) was synthesized with multi-step reactions. The structure of intermediate products and target compound was characterized with spectroscopic techniques. The absorption and emission properties of the synthesized PP-B probe were investigated in detail and it was deduced that PP-B probe possesses a specifically real-time, fluorometric and colorimetric response to Sn(II) and Al(III) in H2O/acetone (v/v: 1:1). The selectivity of the probe was checked in the presence of competing metal ions [Al(III), Zn(II), Cu(II), Cd(II), Fe(II), Sn(II), Hg(II), Co(II), Pb(II), Ga(III), Cr(III)]. It was found that there was a marginal difference in fluorescence response of PP-B towards Sn (II) and Al (III) in the presence of competing metal ions. Under the optimized conditions, 1:2 (ligand:metal) stoichiometries were obtained by Job's plot for Sn(II) and Al(III) complexes, respectively. Cell viability study was carried out to check the applicability of probe in human cancer cell lines. Fluorescence images of the probe (PP-B) in human lung cancer cell lines with XTT (sodium 3′-[1-[(phenylamino)-carbony]-3,4-tetrazolium]-bis(4-methoxy-6-nitro)benzene-sulfonic acid hydrate) test to detect the presence of Sn (II) and Al (III) were acquired by using a confocal laser scanning microscope.