Удосконалення сенсорів з призмовим типом збудження поверхневого плазмонного резонансу на полімерній основі

Abstract

The means related to the improvement of a sensor device on plastic substrate with the prism type of surface plasmon resonance (SPR) excitation in the Kretschmann configuration and with the scanning of the incidence angle of monochromatic light aimed for decreasing of production costs and increasing of sensitivity as well as productivity are considered. It has been shown that application of the laminar polymer substrates after hot press processing, under (180-210 °С) temperature and (300-500 kg/cm 2 ) pressure, will provide disappearance of double refraction and high level in SPR sensor sensitivity because of smoothing surface microrelief. Analysis of the operational characteristics of SPR sensors based on Au and Ag resonant metallic films is performed. Gold displays higher shift of the resonance angle to changes of ambient refraction index and is chemically stable. Silver posses narrower resonance curve thus providing a higher signal/noise ratio of SPR chemical sensors, but has a poor chemical stability. In order to improve sensitivity, measurement accuracy and stability of the SPR instruments operation, two variants for the active metallic coating preparation are proposed: employment of bimetallic Ag/Au (Au as an outer layer) structure in 2:1 ratio that combines the advantages of both layers, as well as pure gold film with subsequent annealing at 120 oC that smoothes the surface microrelief thus stabilizing the sensors characteristics and increasing sensitivity. The main challenge for increasing of productivity consist in the determination of the easiest and most cost-effective way to achieve a high degree of parallelization for high throughput SPR-based analysis. We propose a construction of the sensor in disk format on the basis of the prism scheme of excitation of SPR in the Kretschmann configuration with optical scanning over angles, where a planar chip with integrated gratings for the input-output of light was used as a sensor unit. Thus, the traditional prism and the focusing optics are integrated in a planar sensor unit of the SPR transducer. The unit is placed on a rotating disk, which increases essentially the number of sensitive elements of a sensor. Cheap one-time SPR disks can be produced already now in series with the use of available materials, technologies, and facilities, which opens possibility for the large-scale application. Fig.: 5. Refs: 92 titles.