Abstract
A water-soluble 2',4',6'-trihydroxy phenylazo luminol dye (THPL) with a D-π-A conjugated structure was developed for the first time for the dual-channel spectral sensing of a wide-range of pH values in aqueous solutions, using phloroglucinol as the electron-donating group, heterocycle amide luminol as the electron-accepting one and -NN- as the π-conjugated bridge. Its UV-vis absorption spectrum, especially its spectral response to pH, was investigated in detail. The results confirmed that the proposed THPL exhibited superior UV-vis spectral properties, a strong molar absorption coefficient (εmax = 3.35 × 104 L mol-1 cm-1) and a small half-band width of ca. 126 nm. In particular, either the absorption intensity (Abs) or peak (λmax) changed linearly with pH values from 3.0 to 10.0 under the optimized conditions. Notably, THPL expressed an exclusive dual-channel spectral response to pH, i.e., Abs (a.u.) = 0.1316 + 0.0278 pH (R2 = 0.9921), λmax = 441.5 - 6.64 pH (R2 = 0.9968, pH = 3.0-6.0) and λmax = 359.6 + 7.38 pH (R2 = 0.9879, pH = 6.0-10.0). Under the optimized conditions, THPL was applied to detect pH values in some aqueous and fruit juice samples with satisfactory results. The reversible recognition mechanism was deduced by UV-vis titration, 1H NMR titration and theoretical calculation.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Analytical methods : advancing methods and applications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
