4-(8′-Hydroxyquinolin-7′-yl)methyleneimino-1-phenyl-2,3-dimethyl-5-pyzole as a fluorescent chemosensor for aluminum ion in acid aqueous medium

Abstract

A new fluorescent Al3+-sensor (L) was designed and synthesized from 8-hydroxyquinoline-7-carbaldehyde (HQ7A) and 4-aminopyrine. The sensor exhibited high selectivity and sensitivity “off-on” fluorescent responses toward Al3+ in methanol/water (1:9, v/v, acetate buffer, pH 4.5), with about 26-fold enhancement in fluorescence intensity and high sensitivity with the detection limit for Al3+ as low as 10−7M level. The sensor showed a significant fluorescent enhancement for Al3+ over a wide range of tested metal ions. These suggested that L could be served as a highly selective and sensitive fluorescence sensor for aluminum ion in acid medium, indicating the potential application in acid aqueous environment.