Lensless surface plasmon resonance instrument

A surface plasmon resonance (SPR) instrument comprising:

• an LED holder comprising an LED and an LED aperture through which light emitted by the LED leaves the LED holder;
• a sample holder next to the LED holder with no intervening optical components between the sample holder and the LED holder, the sample holder comprising an entry aperture aligned with the LED aperture and an exit aperture;
• a polarizing filter next to the exit aperture;
• an optical fiber holder comprising an optical fiber aligned with the exit aperture, such that the polarizing filter lies between the exit aperture and the optical fiber;
• a spectrophotometer to which the optical fiber leads;
• and
• at least one additional LED, each at least one additional LED having:
• a corresponding additional LED aperture;
• a corresponding additional entry aperture aligned with the additional LED aperture;
• a corresponding additional exit aperture;
• and
• a corresponding additional optical fiber aligned with the exit aperture;
• and
• a collection fiber bundle into which the optical fiber and the at least one additional optical fiber merge, the collection fiber bundle leading to the spectrophotometer.

A method of performing surface plasmon resonance (SPR) analysis, comprising:

• generating light using a broad spectrum LED;
• passing the light through an LED aperture directly to an entry aperture in a sample holder, the LED aperture and the entry aperture being aligned;
• passing the light from the entry aperture into a prism having a thin metal layer against one wall of the prism;
• passing light reflected by the thin metal layer and refracted by an exit surface of the prism to an exit aperture;
• collecting light leaving the exit aperture at an optical fiber;
• and
• guiding the light along the optical fiber to a spectrophotometer.