A rhodamine B-based colorimetric chemosensor for sensitive and selective detection of Cu~(2+): Test strip analysis and density functional theory

摘要

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