A portable surface plasmon resonance (SPR) sensor system with temperature regulation

We describe here the construction of an inexpensive portable, temperature-regulated surface plasmon resonance (SPR) instrument utilizing readily available components. This system is ideal for both laboratory and field use. Applications of SPR-based biosensors range from laboratory assays to continuous or spot monitoring for analytes important in food industries to monitoring for environmental pollutants and agents of bioterrorism. SPR sensors are capable of measuring minute changes in refractive index (RI) to high precision. Changes in temperature affect the materials of the SPR sensor and RI of aqueous sample solutions. Management of the effects of temperature changes on the SPR signal can be achieved by temperature stabilization, compensation, or a combination of both. The multi-channel design described here allows for a reference channel to compensate for bulk RI changes, non-specific binding, and minor temperature variations, while the temperature controller provides the temperature stability necessary for monitoring small changes in RI. The temperature controller also allows for studies of the temperature dependence of molecular interactions and for optimizing detection conditions. (C) 2003 Elsevier B.V. All rights reserved.