The aim of this paper is to examine the refractometric method of determining the octane number of gasoline and the
presence of organic compounds in biological fuels. A feature of this method is π-shifted etched fiber Bragg grating as
the sensing element utilization, which is characterized by a narrow bandwidth. The advantage of this method is the
detection of changes in the refractive index at the level of 1,3×10-5.
Problems of refractometric optical biosensors and courses of their fast and technological decision are considered. In particular
the resolution and sensitivity increase, formation of stable on amplitude and spectrum cleanliness probing radiation,
allocation of refractometric information from a complex of sensor parameters defined by universality of FBG response
to changes of pressure, temperature and refraction factor, construction of dot type sensors and the distributed
networks on their basis are analyzed.