Colorimetric detection of glutathione by an anionic pyridylazo dye-based Cu2+ complex in the presence of a cationic polyelectrolyte

• Published in: Journal of inclusion phenomena and macrocyclic chemistry Vol. 103; no. 3-4; pp. 123 - 129
• Main Authors: Shimizu, Mahiro, Koizumi, Yoshiaki, Aikawa, Shunichi, Fukushima, Yasumasa
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.04.2023; Springer Nature B.V
• Subjects: Amino acids; Aqueous solutions; Cations; Chemistry; Chemistry and Materials Science; Colorimetry; Copper; Crystallography and Scattering Methods; Dyes; Food Science; Glutathione; Organic Chemistry; Original Article; Polyelectrolytes; Stoichiometry; Polyelectrolyte; Pyridylazo dye; Copper ion; Colorimetric detection; Glutathione
• ISSN: 1388-3127; 1573-1111
• DOI: 10.1007/s10847-023-01183-4

The colorimetric sensing system for glutathione (GSH) was constructed by the mixture of three components, an anionic dye 2-(5-bromo-2-pyridylazo)-5-( N -propyl- N -sulfopropylamino)phenol (BrPAPS), a cationic polyelectrolyte poly(diallyldimethylammonium chloride) (PDADMAC), and Cu 2+ in an aqueous solution. BrPAPS was complexed with Cu 2+ in a 2:1 molar ratio via the electrostatic interaction with PDADMAC (BrPAPS 2 -Cu 2+ -PDADMAC). The addition of GSH to the complex caused a hypsochromic shift with a distinct colorimetric response from red to yellow since the regeneration of the original BrPAPS through the interaction between GSH and Cu 2+ in a 1:1 stoichiometry. BrPAPS 2 -Cu 2+ -PDADMAC allowed the selective recognition of GSH over other amino acids and the detection suffer little interference from them. Hence, BrPAPS 2 -Cu 2+ -PDADMAC provides efficient colorimetric sensing of GSH with high selectivity and sensitivity in pure aqueous media.