Technology and Materials for Sensors Based on Surface Plasmon Resonance

In this chapter provided brieth review of materials and technologies of production sensitive element for surface plasmon resonance sensor (SPR). Adduced in this paper are statistical data, in accord with which the number of publications in scientific journals devoted to the SPR sensor topic is permanently increased by the exponential law and to the end of 2015 reached approximately 6,000. It is indicative of topicality of further investigations aimed at development and creation of new analytical devices based on the SPR principle. Considered in the paper are the main directions to develop technology and construction of the available SPR sensors to increase their sensitivity and accuracy of measurements. It has been shown that lowering the roughness of the plasmon carrying layer and application of an additional dielectric layer with developed surface enables to increase more than two-fold the sensitivity due to increased surface of interaction between the sensitive element (SE) and studied substance. The main technical way to lower the surface roughness is thermal annealing, and the best result can be reached at the annealing temperature 120°C. The promising technological way to enhance the accuracy and sensitivity of measurements is to narrow the reflection characteristic R( ), which can be realized by decreasing the roughness of the metal layer due to changing the geometry of mutual arrangement of the substrate and evaporator. It was ascertained experimentally that when the substrate is placed at the angle 45° between its normal and direction to the evaporator, and the SE metal layer is deposited multiply, the surface roughness of this layer is decreased by 2.5 times: from 2 down to 0.8 nm. As an additional dielectric layer, they often use metal oxides Al2 O3 , TiO2 , SiOxand ZnO, as well as nitrides, for example InN. The presence of this additional dielectric layer enables to reduce the detection limit when measuring the changes in refraction index of the studied substance down to the level 1x10–9, which corresponds to binding the complementary pair antigene–antibody with the concentration of antigene 1 fg/mL. This value of detection limit is by one order lower than that in available commercial analytical devices based on the SPR phenomenon (for instance, 3.10–8, which is typical for commercial Biacore T200). Considered in this review are promising directions for development of sensorics based on SPR, such as application of multilayer graphene coatings and polymer layers prepared using polymerization in high-frequency plasma of inert gas. In our opinion, further development of SPR sensors will be directed to increasing their selectivity, wear resistance of the sensitive element surface, as well as to the methods of receptor regeneration for multiple using the sensitive elements. Based on analisis of reviewed articles, on our opinion, creation SPR-sensors in infrared range of spectrum is perspective for biological researches and immunosensors.