Represented in this paper are the results of investigations aimed at checking up the capabilities of devices based on the surface plasmon resonance (SPR) phenomenon to be applied for studying the properties of water suspensions. As an example, the authors used here the suspensions of tooth pastes Sensodyne and Colgate in distilled water. For measurements, we used the SPR device Plasmon-71 operating in the near infrared spectral range. Results of these measurements were compared to those obtained using the spectrophotometric ones. The measured values of the sedimentation velocity obtained using both the applied methods confirmed availability to efficiently apply SPR devices for studying the opaque multi-component suspensions.

Surface plasmon resonance is used for detecting and measuring various analytes characteristics by sensitive elements in sensor devices. At this, the problem of wear of the sensitive elements, contacting with gaseous and liquid environments whose characteristics are measured, arises during operation of sensor devices based on the surface plasmon resonance phenomenon. Wear of a surface gold nanolayer may be caused by various factors such as maintenance (cleaning before measurements), chemical reactions and abrasiveness of the environment. This problem becomes particularly significant when suspensions are measured. Solid particles in the suspensions have abrasive properties, which leads to modifications of the surface, reduction of the thickness and damage of the sensitive gold layer. As a result, more frequent replacements of sensitive elements are required significantly increasing the measurements cost. In this paper, influence of water suspensions of an optical polishing powder “Polarite” on the wear and the associated changes of the characteristics of a sensitive element is investigated. The need to find solutions of the problem of improving its wear resistance is highlighted.