A highly selective fluorescent probe for colorimetric recognition of cyanide anion based on heptamethine cyanine-triphenylamine conjugate

Abstract

In this work, a novel near-infrared (NIR) dyad T-Cy with a robust CC bond connection between heptamethine cyanine and triphenylamine was synthesized via a modified Suzuki coupling reaction and applied for CN− detection. The probe displayed significant changes in its UV–vis absorption and fluorescence spectra together with a naked-eye visible colour change when CN− was added. The change of spectral signals was linearly proportional to CN− concentration, and the detection limit was calculated to be 14 nM in CH3CN and 0.23 μM in CH3CN/H2O (9/1, v/v), respectively. The probe exhibited high selectivity and anti-interference towards CN− in the presence of other common anions (F−, AcO−, Br−, NO2−, Cl−, SO42−, I−, HCO3−, CO32−, SCN−) and biothiols (Cys/ Hcy/ GSH). Furthermore, the test strips of the probe were verified to be more convenient to detect CN−, and the fluorescence imaging demonstrated that the probe has the potential application in the field of biological system.