RESUMEN
A portable-type surface plasmon resonance (SPR) sensor, composed from a new optical system for multi-sensing, has been developed to apply to environment analysis, clinical diagnosis etc., where many samples are desired to be analyzed at high throughput. The optical system of the sensor consists of a light-emitting diode, a pair of cylindrical lenses, a pair of collimator lenses, a correction lens, a prism, a polarizer and a linear CCD sensor with 2048 pixels. Reflected light from a sensor chip of the width of 6 mm at a certain incident angle was detected by ca. 618 pixels of the linear CCD sensor as an SPR sensor signal. An SPR sensor signal at a specified incident angle is controllable for optimization by adjusting the position of the CCD sensor. A sensor chip having a 30-stripe linear pattern (100 µm width/stripe) was prepared. The spatial resolution as well as the performance of the sensor were evaluated by using sucrose solutions. As a result, the acquisition of SPR sensor signals from 30 sensing points was successfully achieved with a spatial resolution of 100 µm (distance between 2 sensing points). A lower detection limit of ca. 3.2 - 5.5 × 10(-5) RIU with a standard deviation of ±4.5% was obtained by averaging the signals from 6 - 7 pixels of the CCD sensor per one sensing stripe.
RESUMEN
A novel two dimensional surface plasmon resonance (SPR) sensor system with a multi-point sensing region is described. The use of multiplied beam splitting optics, as a core technology, permitted multi-point sensing to be achieved. This system was capable of simultaneously measuring nine sensing points. Calibration curves for sucrose obtained on nine sensing points were linear in the range of 0-10% with a correlation factor of 0.996-0.998 with a relative standard deviation of 0.090-4.0%. The detection limits defined as S/N = 3 were 1.98 × 10(-6) - 3.91 × 10(-5) RIU. This sensitivity is comparable to that of conventional SPR sensors.