Performance of the Spreeta 2000 integrated surface plasmon resonance affinity sensor

Surface plasmon resonance (SPR) has become well established as a laboratory tool for the study of biological binding reactions, but has had limited application outside of this context. With the goal of moving SPR applications from high-cost systems designed for central laboratories to low-cost, portable electronic systems designed for the field, Texas Instruments Inc. (TI), has developed Spreeta, a line of compact, integrated SPR sensor components. This paper reports on the performance of TI's newest SPR device, the Spreeta 2000, measured using instruments developed by TI and by Prolinx Inc., who are developing advanced molecular interaction analysis technology utilizing a proprietary version of Spreeta 2000. Noise optimization techniques including averaging and sum normalization are discussed, and the dependence of refractive index (RI) noise on these techniques is measured. For a measurement time of 0.8 s, a noise level of 1.8 x 10(-7) RI is observed. To estimate the accuracy potentially obtainable using the sensor, the smoothness of the sensor response is measured using RI gradients, and is found to be 0.2% over a change in RI of 0.04. As a demonstration of the capabilities of the Spreeta 2000 when incorporated into an appropriate instrumentation system, an automated assay for mouse IgG is presented. (C) 2003 Elsevier Science B.V. All rights reserved.