Development of new single-mode waveguide surface plasmon resonance sensor using a polymer imprint process for high-throughput fabrication and improved design flexibility

Abstract To promote research on biomolecular interaction analysis, compact, high-precision, and inexpensive biosensors are crucial. Recently, waveguide surface plasmon resonance (WSPR) biosensors have received attention as a means of realizing such devices because their simple composition and structure enables compactness and high precision. These sensor chips are principally fabricated by direct processing of glass that requires complex processing. This results in lower fabrication throughput and higher process cost. Furthermore, such complex processing complicates the fabrication of multifunction sensor chips. In this study, we fabricated a single-mode WSPR sensor chip from polymer materials using an imprinting technique. The application of imprinting techniques makes it possible to achieve high-throughput fabrication, and the selection of polymers as a material offers a wide variety of optical characteristics. The characteristics of these sensors closely match simulation results. We also applied a fibrinogen protein solution to these sensor chips and successfully sensed its adsorption reaction. The refractive index resolution was approximately 3.8 × 10−4 (RIU) with a noise fluctuation of approximately 1.2%. These results demonstrated the effectiveness of the sensor as a compact and inexpensive biosensor.