A rhodamine B‐based colorimetric chemosensor for sensitive and selective detection of Cu2+: Test strip analysis and density functional theory

Abstract

AbstractWe designed a rhodamine B‐based colorimetric chemosensor BHSO ((Z)‐3′,6′‐bis(diethylamino)‐2‐(2‐(((8‐hydroxy‐2,3,6,7‐tetrahydro‐1H,5H‐pyrido[3,2,1‐ij]quinolin‐9‐yl)methylene)amino)ethyl)spiro[isoindoline‐1,9′‐xanthen]‐3‐one) for detecting Cu2+. In the presence of Cu2+, BHSO caused a colour variation from colourless to bright orange. The limit of detection for Cu2+ towards BHSO was 0.73 μM. The binding of BHSO to Cu2+ was analysed as a 1:1 ratio through a Job plot and electrospray ionisation mass spectrometry. BHSO can detect readily Cu2+ with a test strip by colorimetric variation. The detecting process of Cu2+ by BHSO was represented by ultraviolet‐visible titration, electrospray ionisation mass spectrometry, proton nuclear magnetic resonance titration, Job plot and density functional theory calculations.