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

Journal article

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

Authors: Fanna, DJ; Lima, LMP; Craze, AR; Trinchi, A; Wuhrer, R

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: ACS Omega
• Volume: 3
• Issue: 9
• Pages: 10471-10480
• Publication date: 2018-09-04
• DOI: 10.1021/acsomega.8b01483
• EISSN: 2470-1343
• ISSN: 2470-1343
• Language: English
• Keywords: Physical chemistry; Spectrophotometry; Inorganic chemistry; Binding site; Binding constant; Chemistry; Nuclear chemistry; Naked eye; Titration; Stoichiometry; Chromatography; Phenol; Crystallography; Aqueous solution; Electrospray ionization; Analytical Chemistry (journal); Salicylaldehyde; Organic chemistry; Detection limit; Schiff base; Mass spectrometry