SENSOR ELEMENT AND METHOD OF DETECTING CHANGE OF COMPOSITION OF TEST LIQUID OR GASEOUS MEDIUM Russian patent published in 2017 - IPC G01N21/55 

FIELD: measuring equipment.

SUBSTANCE: sensor element for detecting changes in the composition of the test liquid or gaseous medium is a multi-layer nanostructured material with a sensor surface made in the form of a diffraction grid with a period of 300 to 3000 nm, which provides for excitation of surface plasmon polaritons at the boundary sensor surface/test medium (dielectric). The nanostructured material comprises of a serially arranged polymeric substrate, at least one layer of ferromagnetic material and one layer of a noble metal. When implementing the method of detecting a change in the composition of the test liquid or gaseous medium, the above-described sensor element is placed in a container with the test medium providing for a direct contact between the sensor surface of the sensor element and the test medium. The sensor element is then subjected to a TM-polarized optical irradiation with a wavelength λ=400-3000 nm at the angle of incidence θ in the range of 15-70° for the excitation of surface plasmon polaritons. In this case, the sensor element is magnetized by an alternating magnetic field of 10-200 Hz in longitudinal geometry, then the intensity of the electromagnetic wave, reflected from the sensor surface, is recorded by a photoelectric multiplier and analyzed using the equatorial Kerr effect, as a result of which, when detecting a shift of the minimum position relative to the wavelength scale in the reflection spectrum by the wavelength, a conclusion about the change in the composition of the test medium is made.

EFFECT: increase of sensitivity and resolution of the sensor, simplification of the method implementation scheme and provision of integrating the sensor element into biochips by reducing its size.

7 cl, 6 dwg