Optical biosensor system

An optical biosensor system using an internal reflection versus angle of incidence determination for detecting a specific biomolecule, comprising:

• a sensor unit including a transparent plate, at least a portion of one of the faces of said plate having a dielectric film adhered thereto, or being primarily coated with a metal film to which has been adhered a dielectric film, said dielectric film having an affinity for the specific biomolecule at the time the measurement is carried out;
• a light source, including first lens means, for directing a beam of light at an interface of the transparent plate and said metal film or said dielectric film directly adhered thereto to produce an evanescent wave at a sensing surface of said dielectric film when a sample solution contacts said dielectric film on the transparent plate;
• optical imaging instrumentation including second lens means by which one of light reflected from said sensing surface of the transparent plate, light originating from the sample through evanescent wave stimulated fluorescence or phosphorescence, and light originating from scattering at said sensing surface, is imaged on a photodetector device;
• and
• an evaluation unit for determining at least one of an angle of minimum reflectance, a state of polarization, and a collected light intensity;
• wherein at least one sensing surface is arranged on the sensor unit;
• wherein said at least one sensing surface, in order to form an elongated flow cell, is pressed over an upwardly open portion of at least one channel for the sample solution which is to be analyzed and affects at least one of the angle of minimum reflectance, the polarization state for minimum reflectance, and the collected light intensity, at which the evanescent wave interacts with the sample;
• wherein said first lens means forms a convergent beam of light focused in a wedge-shape fashion to form a streak of light extending transversely over all of said at least one sensing surface;
• wherein the photodetector device, at least in the case of more than one sensing surface, is a two-dimensional matrix of individual photodetectors;
• wherein said second lens means is a lens system for imaging rays of one of said reflected light from said at least one sensing surface, said light emitted from the sample, and said light originating from scattering at the sensing surface onto a corresponding column of photodetectors, so that said at least one sensing surface has at least one corresponding column of photodetectors;
• wherein said evaluation unit determines at least one of the angle of minimum reflectance, the state of polarization, and the collected light intensity, for said at least one sensing surface.