Novel pyrazoline-based selective fluorescent probe for the detection of hydrazine

A novel pyrazoline-based fluorescent probe, 2-[4-(3,5-diphenyl-4,5-dihydro-pyrazol-1-yl)-benzylidene]-malononitrile, with a simple structure and low detection limit (6.16 × 10−6 M) for the detection of hydrazine is designed and synthesized. The probe responds selectively to hydrazine over other molecules with marked fluorescence enhancement. The probe can detect hydrazine effectively at pH 5.0–9.0 with a special emission wavelength at 520 nm. Moreover, the probe can be used to detect hydrazine from variety of natural source water.