Ultrasensitive Colorimetric and Ratiometric Detection of Cu2+: Acid-Base Properties, Complexation, and Binding Studies

Daniel J. Fanna, Luís M.P. Lima, Alexander R. Craze, Adrian Trinchi, Richard Wuhrer, Leonard F. Lindoy, Gang Wei, Jason K. Reynolds, Feng Li

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)
103 Downloads (Pure)


Herein, we report the synthesis and characterization of a chemosensor, 5-(diethylamino)-2-(2,3-dihydro-1H-perimidin-2-yl)phenol (HL), synthesized from a condensation between 4-(diethylamino)salicylaldehyde and 1,8-diaminonaphthalene. Upon investigation of the sensing properties of HL, it was found that this sensor may be employed for simple yet efficient detection of Cu2+ in aqueous methanol solutions. The selective and ratiometric response to Cu2+ yielded an outstandingly low limit of detection of 3.7 nM by spectrophotometry and is also useful as a naked-eye sensor from 2.5 μM. The system was studied by spectrophotometric pH titrations to determine Cu2+ binding constants and complex speciation. Binding of Cu2+ to HL occurs in 1:1 stoichiometry, in good agreement with high-resolution electrospray ionization mass spectrometry (ESI-HRMS) results, Cu2+ titrations, and Job's plot experiments, while the coordination geometry was tentatively assigned as square pyramidal by spectroscopic studies.

Original languageEnglish
Pages (from-to)10471-10480
Number of pages10
JournalACS Omega
Issue number9
Publication statusPublished - 4 Sep 2018


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