| 摘要 |
<p>There is described a surface plasmon resonance biosensor in which light is internally reflected at an internal surface of a transparent block (1). Against a surface (3) of the block is formed a layer (10) of silver overlayed by a layer (11) of sensitive material. The sensor monitors the change in refractive index of the layer (11) as the sensitive material reacts with a sample (not shown) in the area adjacent the sensitive material. This is achieved by creating the conditions necessary for surface plasmon resonance as the light is internally reflected. To do this, the angle of incidence at the internal surface must be correct and this is difficult to achieve without relatively sophisticated optics. In the invention the correct angle is achieved in a block having the form of a thin sheet by providing, on a surface (2) opposite surface(3) a diffraction grating (7) and passing the light from the light source (not shown) through this grating and thence taking just one of the thus diffracted beams entering the sheet (1) at a suitable angle. Other embodiments describe alternative ways of achieving the same object.</p> |
