A highly sensitive and selective on–off fluorescent sensor based on a complex of polySchiff-Fe2+ for Cr(vi) detection in an aqueous medium

Abstract

Designing exceptional probes to detect minute quantities of chromium(VI) is of huge importance for the safety and health of the human race. In this study, a green fluorescence emission probe (polyethylene Schiff base-chelated Fe²⁺ complex) was synthesized by a one-pot synthesis method for the highly selective and sensitive detection of Cr(VI) in an aqueous solution. The complex of polyethylene Schiff-Fe²⁺ was fully characterized, and it displayed satisfactory stability in the aqueous solution. The fluorescence emission could be quenched specifically by the introduction of Cr(VI) via the oxidation of the Fe²⁺-centered polyethylene Schiff base complex. The fluorescence intensity decreases linearly with the concentration of Cr(VI), and the corresponding detection limit was calculated to be 0.18 μM. Thus, the obtained fluorescence detection system could be used for Cr(VI) detection in tap water. These features provide potential uses of the as-prepared polyethylene Schiff-Fe²⁺ complex as a sensor for environmental applications.