A selective carbazole-based fluorescent probe for chromium(iii)

Abstract

A novel carbazole derivative, N,N′-bis(9-ethyl-9H-carbazol-3-yl)-(ethane-1,2-diamine), has been synthesized by reacting 3-amino-9-ethylcarbazole with glyoxal and characterized by 1H NMR, infrared spectroscopy, elemental analysis and mass spectra. The strong fluorescence emission at 438 nm of the derivative is effectively and selectively quenched by Cr3+. A 1 : 1 complex is formed between the carbazole derivative and Cr3+ and their association constant is 1.4 × 104 L mol−1. The results indicate that the carbazole derivative can provide a rapid, selective and sensitive response to Cr3+ in a linear dynamic range 1.0–20 μmol L−1 with a limit of detection of 0.10 μmol L−1 at pH 7.4. Common interferent ions do not show any interference with the Cr3+ determination. It is anticipated that the carbazole derivative could be a good candidate probe and has potential application for Cr3+ determination.