In this work, salicylaldehyde fluorescein hydrazone (1) was synthesized and characterized. Exhibiting reversible color changes responding to different pH in the presence of Cu(II) in buffered media, 1 could be applied as a colorimetric chemosensor for the detection of pH and Cu(II) bi-functionally. It presented a tunable system integrated with a Cu(II)-driven YES logic gate as well as an INHIBIT logic gate, with pH and Cu(II) as its chemical inputs based on encoding binary digits of logical conventions.