Selective binding of Ni 2+ and Cu 2+ metal ions with naphthazarin esters isolated from Arnebia euchroma

• Published in: Biotechnology progress Vol. 36; no. 4; p. e2985
• Main Authors: Sharma, Nidhi, Gulati, Ashu
• Format: Journal Article
• Language: English
• Published: United States 01-07-2020
• Subjects: sensing; naphthaquinones; copper/nickel complex; chelation
• ISSN: 8756-7938; 1520-6033
• DOI: 10.1002/btpr.2985

Naphthazarin esters (C1-C4) isolated from the roots of Arnebia euchroma are found as skilled dual chemosensors for Ni
and Cu
among Pb
, Na
, K
, Hg
, Mg
, and Ca
metal ions. C1-C4 esters exhibited a red shift of 54 nm with Ni
and 30 nm with Cu
metal ions in absorption. There is a formation of red-shifted bands between 517 and 613 nm in the absorption spectrum of C1-C4 sensors on binding with Ni
and Cu
ions. The addition of Ni
and Cu
ions to sensors C1-C4 stimulates a remarkable color change from reddish pink to purple and light blue, respectively. These color changes can be identified with the naked eye. The significant downfield shifts of CO and OH peaks in nuclear magnetic resonance (NMR) spectrum confirm the chelation as binding mechanism. With ultraviolet-visble and NMR studies, it is found that C1-C4 esters possessed notable selectivity and sensitivity toward Ni
and Cu
over other metal ions.