Chemosensing in deep red: A squaraine-based fluorescent chemosensor for pH

✍ Scribed by Yasemin G. Isgor; Engin U. Akkaya

• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 207 KB
• Volume: 38
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(97)01745-0

✦ Synopsis

We have synthesized and spectrally characterized a squaraine-based fluorescent chemosensor for pH. This ehemosensor unlike many others, works in 100 % aqueous solutions, signalling the pH change from 10 to 7 by a 14-fold increase in the emission intensity at 651 nm, when excited at the isosbestie point (614 nm). The average pK, for the iohizable groups is found to be 8.8. The chemosensor with its molar extinction coefficient > 200,000 and the quantum yield of 0.2, yield an impressive intrinsic brightness value of 40,000.