ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A curcumin-loaded silica carrier with NH₃ sensitivity and antimicrobial properties

Ligia Todan, Mariana Voicescu, Daniela C. Culita, Daniel Lincu, Rodica M. Ion, Mariana Călin, Iuliana Răut, and Andrei C. Kuncser

“Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, Bucharest, Romania

E-mail: l_todan@yahoo.co.uk

Received: 25 August 2021  Accepted: 19 January 2022

Abstract:

In this study curcumin was immobilized in a silica matrix to overcome its poor aqueous solubility and rapid degradation profile. Two kinds of sol–gel powders based on colloidal silica were synthesized and characterized, one prepared with an ethanolic solution of curcumin and the other using cethyltrimethylammonium bromide (CTAB) to solubilize the dye. The successful integration of curcumin in the matrix as well as the interaction with the components of the composite powders was validated by different analysis methods (DSC, FTIR). The samples morphology was evaluated by SEM. UV–Vis and fluorescence studies showed that curcumin was stable, in its enol configuration in both matrices. The sensitivity to ammonia was proved by exposing the powders to NH₃ vapors in a sealed vessel. Color changes were measured with a colorimeter. UV–Vis spectra showed that the enol form of the dye in EtOH/CTAB based SiO₂ matrices was energetically stable under NH₃ atmosphere, even after being kept a few days at low temperature. A fluorescence quenching of both samples was noticed due to interaction curcumin-ammonia. Both samples have antimicrobial properties, the CTAB containing one being more efficient. The EtOH/CTAB based SiO₂ powders may represent a novel signaling and antimicrobial system, useful for food or pharmaceutical applications.

Graphical Abstract

Keywords: Curcumin; Silica; Ammonia vapors; Fluorescence; Colorimetric analysis

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02090-7

Chemical Papers 76 (5) 3087–3096 (2022)