Abstract: The reversible optical sensing membrane for the determination of benzyl amine is described.It incorporates dinaphthyl macrocyclic polyether as the ionophore of benzyl amine cation and lipophilic pHindictor in a plasticzed PVCmembrane.The competitive binding of benzyl amine cation and hydrogen ion in the membrane yields large absorbance changes which can easily be measured in the visible spectral range.The response performance of this sensor and its theoretical response equations are reported.

Key words: Optical sensor, lonophore, Benzyl amine, pH Indicator