Irreversible coumarin based fluorescent probe for selective detection of Cu2+ in living cells

Abstract

Copper ion (Cu2+) is an essential part of the living organisms. Cu2+ ions play a vital role in many biotic processes. An abnormal amount of Cu2+ ions may result in serious diseases. Herein, a novel “fluorescent ON” probe NC-Cu to trace minute levels of Cu2+ ions in presence of various biological active species has been developed. Lysosomal cells targeting group (Morpholine) was added to the probe. The spectral properties of probe NC-Cu were recorded in HEPES buffer (0.01 M, pH = 7.4, comprising 50% CH3CN, λex = 430 nm, slit: 5 nm). The synthesized probe NC-Cu work based on copper promoted catalytic hydrolysis of hydrazone and shows remarkable fluorescence enhancement. The reaction of the probe with Cu2+ ions was completed within 20 min. An excellent linear relationship (R2 = 0.9952) was found and the limit of detection (LOD, according to the 3σ/slope) for Cu2+ ions was calculated to be 5.8 µM. Furthermore, NC-Cu was effectively functional in the living cells (KYSE30 cells) to trace Cu2+ ions.