Synthesis of a novel hexaazatriphenylene derivative for the selective detection of copper ions in aqueous solution

• Published in: RSC advances 2019-12, Vol.9 (68), p.39824-39833
• Main Authors: Saeed, Tahseen S, Maddipatla, Dinesh, Narakathu, Binu B, Albalawi, Sarah S, Obare, Sherine O, Atashbar, Massood Z
• Format: Article
• Language: English
• Subjects: Absorbance; Aqueous solutions; Chemical sensors; Chemistry; Colorimetry; Copper; Drinking water; Environmental protection; Fluorescence; Linearity; Selectivity; Stoichiometry; Toxicity
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c9ra08825c

A hexaazatriphenylene (HAT) derivative, naphtho[2,3-h]naphtho[2′,3':7,8]quinoxalino[2,3- a ]naphtho[2′,3′:7,8]quinoxalino[2,3- c ]phenazine-5,10,15,20,25,30-hexaone (NQH) was synthesized, characterized, and found to have novel properties in being selective toward the detection of copper (Cu 2+ ) ions. The capability of NQH to be employed as a colorimetric, chemo-fluorescence and electrochemical sensor for the detection of Cu 2+ was demonstrated by performing UV-Vis absorbance, fluorescence intensity, and cyclic voltammetry (CV) measurements. The interaction between NQH and Cu 2+ was initially observed with an obvious color change from yellow to brown upon the addition of Cu 2+ ions to NQH. The interaction was also confirmed by UV-Vis absorbance, fluorescence intensity, and mass spectroscopy (MS/MS) measurements. UV absorbance, fluorescence and CV of NQH toward Cu 2+ showed good linearity with a detection limit of 3.32 μM, 2.20 μM and 0.78 μM, respectively, which are lower than the toxicity levels of copper in drinking water (20-30 μM) set by the U.S. Environmental Protection Agency (EPA) and World Health Organization (WHO). A 1 : 2 stoichiometry complexation between NQH and Cu 2+ was confirmed by Job's plot and MS/MS. In addition, the selectivity and sensitivity of the NQH compound towards Cu 2+ ions were further confirmed by performing CV on a screen printed flexible and planar electrochemical sensor. A hexaazatriphenylene (HAT) derivative, naphtho[2,3- h ]naphtho[2′,3′:7,8]quinoxalino[2,3- a ]naphtho[2′,3′:7,8]quinoxalino[2,3- c ]phenazine-5,10,15,20,25,30-hexaone (NQH) was synthesized, characterized, and found to be selective to copper (Cu 2+ ) ions.