A guaiazulene-based highly selective colorimetric sensor for cyanide ion detection in aqueous medium and food samples


Bektaş N., DAŞTAN A., Erdoğan M., Aydoğan A.

Journal of Molecular Liquids, cilt.423, 2025 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 423
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.molliq.2025.127038
  • Dergi Adı: Journal of Molecular Liquids
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, Chimica, Compendex, INSPEC
  • Anahtar Kelimeler: Azulene, Colorimetric sensor, Cyanide detection, Guaiazulene
  • Atatürk Üniversitesi Adresli: Evet

Özet

A novel colorimetric sensor (4) for cyanide detection was designed based on guaiazulene which is a natural blue pigment. The sensor 4 was synthesized in excellent yield starting from guaiazulene in two simple reaction steps consisting of formylation of guaiazulene by the Vilsmeier-Haack reaction and subsequent Knoevenagel condensation reaction of 3-formylguaiazulene (2) with 1,3-indanedione (3). Structural characterization of sensor 4 was elucidated by means of various spectroscopic techniques such as 1H-, 13C NMR, and HRMS. The nucleophilic addition of cyanide to the β-conjugated carbon of 1,3-indanedione scaffold breaks intramolecular charge transfer (ICT), subsequently causing a significant change in its photophysical properties resulting in a color change, that can be observed with naked eye. Cyanide sensory properties of 4 were studied in detail with UV/Vis spectroscopy in aqueous DMSO and revealed a limit of detection as low as 1.72 μM with a very high selectivity among the various competing anions. The detection of cyanine in tab water and a food sample was also demonstrated along with filter paper-based smart phone application.