Researchers at the Institute of Automation and Electrometry (Siberian Branch, Russian Academy of Sciences)   and the Institute of Organic Chemistry (Siberian Branch, Russian Academy of Sciences) have for the first time designed a chemical sensor based on optical fiber, which selectively reacts to butylamine presence. The research has been sponsored by the Division of Physical Sciences of the Russian Academy of Sciences, integration project of Siberian Branch of the Russian Academy of Sciences and the State Program for Support of Leading Scientific Schools. The findings were published in the “Solid-State Physics” journal.

Amines – are ammonia derivatives. They are commonly used in the chemical industry but working with them requires strict safety technique adherence as multiple amines are very toxic. To timely detect leakage, it is necessary to install chemical sensors in the premises where work is being executed with these substances. However, the sensors applied currently possess low selectivity and high level of mulfunction.

Domestic researchers guided by Alexander Plekhanov have created a sensor that specifically detects butylamine – one of the most toxic and highly explosive amines. The sensor operation is based on the fact that luminescent dye molecules are able to change luminescence spectrum via binding with the toxic agent. These sensor-molecules were built into the matrix of silica nanoparticles applied on the optical fiber butt end.

The laser located at the fiber back-end inputs light impulses. In response to them, dye molecules emit their own luminescence, which is analyzed by the spectrometer. In an ordinary situation, the peak in the 660 nm area is well-seen in the nanofilm spectrum. Should the dye be bound with toxic butylamine, it disappears, and green-yellow luminescence appears at 560 nm wavelength.

The authors point out that the chemical reaction used by them is highly selective: spectrum change is observed when butylamine is added but not other similar substances. This means that probability of the system’s malfunction is very low. The researchers have also demonstrated that sensor sensitivity can be increased by changing molecular structure of the film that contains the dye. They have found out that applying an artificial opal “mirror” on the film and incorporation of silver nanoparticles in it allow to increase cumulative luminescence intensity by 10 times, “thus opening a prospect to creation of selective optical chemical sensors for remote monitoring”.

Source of information:

I.A. Boldov, A.S. Kouchianov, A.I. Plekhanov, N.A. Orlova, I. Yu. Kargapolova, V.V. Shelkovnikov “Fiber-optic chemical sensor for amine-type compounds”. Solid-State Physics, 2011, Vol. 53, issue 6.

Mikhail Petrov