A novel naphthaldehyde–benzothiazole conjugated sensor Z was successfully synthesized and characterized. Chemosensor Z showed highly selective and sensitive for the detection of Al3+ in DMF/H2O (v/v, 4/6) attributed to the combined contribution of excited-state intramolecular proton transfer (ESIPT), CN isomerization and chelation enhanced fluorescence (CHEF). The binding ratio of Z to Al3+ was 1:1 which was further determined by job’s plot and HRMS. The detection limit was calculated 4.56 × 10−7 M and 5.09 × 10−8 M in corresponding Al3+ concentration range of 0–22 μM and 24–44 μM, respectively. Furthermore, Z was successfully practiced for the Al3+ quantitative analysis in real water samples, logic gate construction and bioimaging in human stromal cells (HSC).