10.1186/2228-5326-2-16

Thin film optical BTB pH sensors using sol–gel method in presence of surfactants

HTML PDF
  • Issa M El Nahhal*1,
  • Shehata M Zourab1,
  • Fawzi S Kodeh1,
  • Alaa I Qudaih1,
  1. Chemistry Department, Al-Azhar University of Gaza, Gaza, 1277, PS
Cover Image

Published in Issue 2012-07-18

How to Cite

El Nahhal, I. M., Zourab, S. M., Kodeh, F. S., & Qudaih, A. I. (2012). Thin film optical BTB pH sensors using sol–gel method in presence of surfactants. International Nano Letters, 2(1 (December 2012). https://doi.org/10.1186/2228-5326-2-16
Crossref
Scopus
Google Scholar
Europe PMC

HTML views: 22

PDF views: 144

Abstract

Abstract Bromothymol blue (BTB) thin films were prepared by depositing a thin layer of a solution containing tetraorthosilicate and BTB pH indicator in the presence of surfactants, namely cetyltrimethylammonium bromide (C 19 H 42 BrN, CTAB) or dodecyldimethylamine oxide (C 14 H 31 NO, 69%), C 16 H 35 NO (11%), Genaminox LA onto a glass slide substrate. CTAB or GLA surfactants were used to improve the mesostructure of the host material and to increase its porosity. Optical BTB thin films were found to be sensitive against pH and behave as free BTB. This provides evidence for weak interactions between the BTB molecules and the host silica matrix. The effects of the sol mixture on the stability and reproducibility and the colorimetric response to solutions of different pH were examined and pKa values were determined. The BTB thin film sensors showed an advantage over the encapsulated monolithic sensors in which the thin film sensors exhibit a faster response time than the monolithic disks. These pH sensors showed reproducibility and high stability behavior.

Keywords

  • Bromothymol blue,
  • Optical thin films,
  • pH sensors,
  • Surfactants,
  • Tetraorthosilicate
HTML PDF

References

  1. Zusman et al. (1990) Doped sol–gel glasses as chemical sensors https://doi.org/10.1016/0022-3093(90)90232-B
  2. Wolfbels (2008) Fiber-optic chemical sensors and biosensors https://doi.org/10.1021/ac800473b
  3. Jeronimo et al. (2007) Optical sensors and biosensors based on sol–gel films review article https://doi.org/10.1016/j.talanta.2006.09.029
  4. VonBultzingslowen et al. (2002) Sol–gel based optical carbon dioxide sensor employing dual luminophore referencing for application in food packaging technology https://doi.org/10.1039/b207438a
  5. Chodavarapu et al. (2007) CMOS integrated luminescence oxygen sensor system https://doi.org/10.1049/el:20070837
  6. Miled et al. (2004) An optical fibre pH sensor on dye doped mesostructured silica https://doi.org/10.1016/j.jpcs.2004.05.005
  7. Jurmanovic et al. (2010) Organically modified silicate thin films with colorimetric pH indicators methyl red and bromocresol green as pH responsive sol–gel hybrid material https://doi.org/10.1016/j.tsf.2009.07.158
  8. Lev et al. (1995) Organically modified sol–gel sensors https://doi.org/10.1021/ac00097a711
  9. Dash et al. (2008) Organically modified silica: synthesis and applications due to its surface interaction with organic molecules https://doi.org/10.1016/j.cis.2007.12.006
  10. Lu et al. (1997) Continuous formation of the supported cubic and hexagonal mesoporous films by sol–gel dip coating https://doi.org/10.1038/38699
  11. Rottman et al. (1999) Surfactant-induced modification of dopents in sol–gel matrixes https://doi.org/10.1021/ja991269p
  12. El Nahhal et al. (2009) Behaviour of trapped bromothymol blue into sol–gel matrix in presence of CTAB https://doi.org/10.1080/01932690802548429
  13. Zaggout and J (2006) Encapsulation of bromothymol blue pH indicator into sol–gel matrix https://doi.org/10.1080/01932690500265854
  14. El Nahhal et al. (2011) Encapsulation of bromothymol blue into a polysiloxane network matrix in the presence of surfactants https://doi.org/10.1080/01932691.2010.488127
  15. Safavi et al. (2007) Modification of chemical performance of dopants in xerogel films with entrapped ionic liquid https://doi.org/10.1039/b613288j