P4.1 - Investigation of Nanofilm Influence on Optical Sensor’s Characteristics
- Event
- SENSOR+TEST Conferences 2009
2009-05-26 - 2009-05-28
Congress Center Nürnberg - Band
- Proceedings SENSOR 2009, Volume II
- Chapter
- P4 - Optical Sensors
- Author(s)
- S. Krutovertsev, A. Borisov, M. Chuprin, O. Ivanova, S. Kuleshov - JSC “Ecological sensors and systems”, Moscow, Russia
- Pages
- 363 - 366
- DOI
- 10.5162/sensor09/v2/p4.1
- ISBN
- 978-3-9810993-5-5
- Price
- free
Abstract
A particular place among optical methods of analysis is occupied by chemical sensors based on effect of frustrated total internal reflection and thin films of substances, which alter their optical features under effect of environment contents. It is known, that some organic substances are sensitive for gases micro-concentrations at a room temperature, for example, organic dyes. Many pH dyes have been inserted in sol-gels for the pH sensing and acid-base gases including CO2 and NH3. The fundamental opportunity for creation of optical NH3 sensor based on the film of 4-[4-(dimethylamino)phenylazo]benzenesulfonic acid sodium salt (Methyl Orange), immobilized within Nafion® have been presented.
The maximum of absorbance spectrum of the film drifts to the short wave range from λmax = 522 nm to λmax = 464 nm in the presence of ammonia. Therefore according to Fresnel’s law, the intensity of reflected light under the angle close to critical increases on the wave-length equal to 522 nm. The influence of matrix nature on primary parameters of optical NH3 sensor was investigated in this work. Films of Nafion® and SiOx were investigated as matrixes. The sensitivity, dependence of sensor signal on humidity and dynamic parameters of sensors were determined.