Development of New Localized Surface Plasmon Resonance Sensor with Nanoimprinting Technique

A new localized surface plasmon resonance sensor fabricated by the nanoimprinting technique is presented. Nanoimprinting, one of the most important nanofabrication technologies, can produce stable nanopatterns on a substrate with high throughput. In this study, we apply this technique to the preparation of sensor chips for a low-cost and reliable biosensor. The optimal cross-sectional structure of the sensor chip was calculated by a two-dimensional finite-difference time domain (FDTD) simulation method. The sensor chip with the optimized structure was fabricated by nanoimprinting of the nanopatterned metal mold onto a UV-curable resin and subsequent sputtering of a thin gold film. Using this fabrication process, an extremely large number of sensor chips can easily be produced from a single metal mold with high accuracy and reproducibility. The characteristics of the fabricated sensor chips were evaluated by measuring their absorption spectra. The absorption peak due to the localized SPR could be observed, which was almost consistent with the simulation result. The sensitivity of this sensor chip was confirmed to be comparable with that of the standard localized SPR sensor under development. The low-cost, stable, high-sensitivity biosensors that can be constructed by the present process will generate practical protein chips and point-of-care chips, which are expected to become key diagnosis tools in the future