Greener development of highly selective turn-on fluorogenic chemo sensor for Cd2+ - Cell imaging and test strips studies

Abstract

Abstract A Novel chemosensor derived from 4- aminoantipyrine and 9- anthracene carboxaldehyde (Aminoantipyrinoanthracenyl imine) (AAPAI) was synthesized by microwave irradiation in a greener approach and characterized by FT-IR, 1H- NMR and HR-LCMS mass spectrum. The specific selectivity in sensing of Cd2+ was effectively studied by colorimetric and fluorescence technique. The chemosensor display strong “turn-on” fluorescence and promising selectivity towards sensing of Cd2+.The sensing was confirmed by UV–Visible spectrum with an isobestic point at 430 nm. AAPAI forms 1:1 complex with Cd2+ which was further confirmed by HR-LCMS mass spectrum and Job's plot analysis. The mechanism of sensing is based on Photo induced electron transfer (PET) and Chelation enhanced fluorescence (CHEF). When Cd2+ binds with AAPAI the PET process gets inhibited thereby enhancing the fluorescence intensity and CHEF takes place due to the binding of Cd2+ with AAPAI. The reversibility of AAPAI was analyzed by EDTA and the detection limit was found out to be 0.02 μM. Real sample analysis was performed by using AAPAI and various water samples. DFT study supports the four coordination of Cd2+ with AAPAI. Fluorescence cell imaging of this Cd2+ complex acts as a supporting evidence of the fluorescent nature in L929 cells which is anchored by the results of test strips study.