Measuring method and apparatus using attenuation in total internal reflection

A measuring method for detecting a state of attenuation in total internal reflection by the use of a measuring apparatus comprising

• a measuring unit comprising a first light source emitting a first light beam;
• a measuring chip consisting of a first dielectric block transparent to the first light beam, a first metal film formed on one face of the first dielectric block and a first sample liquid holding system which holds a sample liquid on the surface of the first metal film, the sample liquid comprising solvent and a sample;
• a sensing material which can be combined with a specific material in the sample liquid and is disposed on the first metal film;
• a first optical system which causes the first light beam to enter the first dielectric block to impinge upon the interface of the first dielectric block and the first metal film at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a first photodetector means which detects the intensity of the first light beam reflected in total internal reflection at the interface of the first dielectric block and the first metal film,
• a reference unit comprising a second light source emitting a second light beam;
• a reference chip consisting of a second dielectric block transparent to the second light beam, a second metal film formed on one face of the second dielectric block and a second sample liquid holding system which holds a false sample liquid on the surface of the second metal film, the false sample liquid comprising said solvent;
• a sensing material which can be combined with said specific material in the sample liquid and is disposed on the second metal film;
• a second optical system which causes the second light beam to enter the second dielectric block to impinge upon the interface of the second dielectric block and the first metal film at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a second photodetector means which detects the intensity of the second light beam reflected in total internal reflection at the interface of the second dielectric block and the second metal film, and
• a measuring means which corrects result of detection by the first photodetector means on the basis of result of detection by the second photodetector means and measures the change of a state of attenuation in total internal reflection due to generation of surface plasmon resonance on the basis of the corrected result of detection by the first photodetector means,
• wherein the improvement comprises the steps of
• detecting the difference in sensitivity between the measuring unit and the reference unit before initiating the measurement of the change of a state of attenuation in total internal reflection, and
• calibrating result of measurement by the measuring means on the basis of the difference in sensitivity between the measuring unit and the reference unit.

A measuring method for detecting a state of attenuation in total internal reflection by the use of a measuring apparatus comprising

• a measuring unit comprising a first light source emitting a first light beam;
• a measuring chip consisting of a first dielectric block transparent to the first light beam, a clad layer formed on one face of the first dielectric block, an optical waveguide layer which is formed on the clad layer and a first sample liquid holding system which holds a sample liquid on the surface of the clad layer, the sample liquid comprising solvent and a sample;
• a sensing material which can be combined with a specific material in the sample liquid and is disposed on the clad layer;
• a first optical system which causes the first light beam to enter the first dielectric block to impinge upon the interface of the first dielectric block and the clad layer at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a first photodetector means which detects the intensity of the first light beam reflected in total internal reflection at the interface of the first dielectric block and the clad layer,
• a reference unit comprising a second light source emitting a second light beam;
• a reference chip consisting of a second dielectric block transparent to the second light beam, a clad layer formed on one face of the second dielectric block, an optical waveguide layer which is formed on the clad layer and a second sample liquid holding system which holds a false sample liquid on the surface of the clad layer, the false sample liquid comprising said solvent;
• a sensing material which can be combined with said specific material in the sample liquid and is disposed on the clad layer;
• a second optical system which causes the second light beam to enter the second dielectric block to impinge upon the interface of the second dielectric block and the clad layer at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a second photodetector means which detects the intensity of the second light beam reflected in total internal reflection at the interface of the second dielectric block and the clad layer, and
• a measuring means which corrects result of detection by the first photodetector means on the basis of result of detection by the second photodetector means and measures the change of a state of attenuation in total internal reflection due to excitation of waveguide mode on the basis of the corrected result of detection by the first photodetector means,
• wherein the improvement comprises the steps of
• detecting the difference in sensitivity between the measuring unit and the reference unit before initiating the measurement of the change of a state of attenuation in total internal reflection, and
• calibrating result of measurement by the measuring means on the basis of the difference in sensitivity between the measuring unit and the reference unit.

A measuring apparatus utilizing the phenomenon of attenuation in total internal reflection comprising

• a measuring unit comprising a first light source emitting a first light beam;
• a measuring chip consisting of a first dielectric block transparent to the first light beam, a first film layer formed on one face of the first dielectric block and a first sample liquid holding system which holds a sample liquid on the surface of the first film layer, the sample liquid comprising solvent and a sample;
• a sensing material which can be combined with a specific material in the sample liquid and is disposed on the first film layer;
• a first optical system which causes the first light beam to enter the first dielectric block to impinge upon the interface of the first dielectric block and the first film layer at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a first photodetector means which detects the intensity of the first light beam reflected in total internal reflection at the interface of the first dielectric block and the first film layer,
• a reference unit comprising a second light source emitting a second light beam;
• a reference chip consisting of a second dielectric block transparent to the second light beam, a second film layer formed on one face of the second dielectric block and a second sample liquid holding system which holds a false sample liquid on the surface of the second film layer, the false sample liquid comprising said solvent;
• a sensing material which can be combined with said specific material in the sample liquid and is disposed on the second film layer;
• a second optical system which causes the second light beam to enter the second dielectric block to impinge upon the interface of the second dielectric block and the first film layer at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a second photodetector means which detects the intensity of the second light beam reflected in total internal reflection at the interface of the second dielectric block and the second film layer, and
• a measuring means which corrects result of detection by the first photodetector means on the basis of result of detection by the second photodetector means and measures the change of a state of attenuation in total internal reflection on the basis of the corrected result of detection by the first photodetector means,
• wherein the improvement comprises that
• there is further provided a sensitivity difference detecting means which detects the difference in sensitivity between the measuring unit and the reference unit before initiating the measurement of the change of a state of attenuation in total internal reflection, and
• said measuring means calibrates result of measurement on the basis of the difference in sensitivity between the measuring unit and the reference unit.

A measuring apparatus utilizing the phenomenon of attenuation in total internal reflection comprising

• a measuring unit comprising a first light source emitting a first light beam;
• a measuring chip consisting of a first dielectric block transparent to the first light beam, a first metal film formed on one face of the first dielectric block and a first sample liquid holding system which holds a sample liquid on the surface of the first metal film, the sample liquid comprising solvent and a sample;
• a sensing material which can be combined with a specific material in the sample liquid and is disposed on the first metal film;
• a first optical system which causes the first light beam to enter the first dielectric block to impinge upon the interface of the first dielectric block and the first metal film at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a first photodetector means which detects the intensity of the first light beam reflected in total internal reflection at the interface of the first dielectric block and the first metal film,
• a reference unit comprising a second light source emitting a second light beam;
• a reference chip consisting of a second dielectric block transparent to the second light beam, a second metal film formed on one face of the second dielectric block and a second sample liquid holding system which holds a false sample liquid on the surface of the second metal film, the false sample liquid comprising said solvent;
• a sensing material which can be combined with said specific material in the sample liquid and is disposed on the second metal film;
• a second optical system which causes the second light beam to enter the second dielectric block to impinge upon the interface of the second dielectric block and the first metal film at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a second photodetector means which detects the intensity of the second light beam reflected in total internal reflection at the interface of the second dielectric block and the second metal film, and
• a measuring means which corrects result of detection by the first photodetector means on the basis of result of detection by the second photodetector means and measures the change of a state of attenuation in total internal reflection due to generation of surface plasmon resonance on the basis of the corrected result of detection by the first photodetector means,
• wherein the improvement comprises that
• there is further provided a sensitivity difference detecting means which detects the difference in sensitivity between the measuring unit and the reference unit before initiating the measurement of the change of a state of attenuation in total internal reflection, and
• said measuring means calibrates result of measurement on the basis of the difference in sensitivity between the measuring unit and the reference unit.

A measuring apparatus utilizing the phenomenon of attenuation in total internal reflection comprising

• a measuring unit comprising a first light source emitting a first light beam;
• a measuring chip consisting of a first dielectric block transparent to the first light beam, a clad layer formed on one face of the first dielectric block, an optical waveguide layer which is formed on the clad layer and a first sample liquid holding system which holds a sample liquid on the surface of the clad layer, the sample liquid comprising solvent and a sample;
• a sensing material which can be combined with a specific material in the sample liquid and is disposed on the clad layer;
• a first optical system which causes the first light beam to enter the first dielectric block to impinge upon the interface of the first dielectric block and the clad layer at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a first photodetector means which detects the intensity of the first light beam reflected in total internal reflection at the interface of the first dielectric block and the clad layer,
• a reference unit comprising a second light source emitting a second light beam;
• a reference chip consisting of a second dielectric block transparent to the second light beam, a clad layer formed on one face of the second dielectric block, an optical waveguide layer which is formed on the clad layer and a second sample liquid holding system which holds a false sample liquid on the surface of the clad layer, the false sample liquid comprising said solvent;
• a sensing material which can be combined with said specific material in the sample liquid and is disposed on the clad layer;
• a second optical system which causes the second light beam to enter the second dielectric block to impinge upon the interface of the second dielectric block and the clad layer at various angles of incidence so that total internal reflection conditions are satisfied at the interface;
• and a second photodetector means which detects the intensity of the second light beam reflected in total internal reflection at the interface of the second dielectric block and the clad layer, and
• a measuring means which corrects result of detection by the first photodetector means on the basis of result of detection by the second photodetector means and measures the change of a state of attenuation in total internal reflection due to excitation of waveguide mode on the basis of the corrected result of detection by the first photodetector means,
• wherein the improvement comprises that
• there is further provided a sensitivity difference detecting means which detects the difference in sensitivity between the measuring unit and the reference unit before initiating the measurement of the change of a state of attenuation in total internal reflection, and
• said measuring means calibrates result of measurement on the basis of the difference in sensitivity between the measuring unit and the reference unit.

A measuring method for analyzing a sample by the use of a measuring apparatus comprising;

• a measuring chip consisting of a dielectric block, a film layer formed on one face of the dielectric block and a sample holding system which holds the sample on the surface of the film layer;
• a light source which emits a light beam;
• an optical system which causes the light beam to enter the dielectric block at an angle of incidence such that total internal reflection conditions are satisfied at the interface of the dielectric block and the film layer;
• and a photodetector means which detects the intensity of the light beam reflected in total internal reflection at the interface, wherein the improvement comprises the steps of
• measuring the refractive indexes of a plurality of reference samples whose refractive indexes are known, thereby obtaining a calibration standard on the basis of result of measurement on the reference samples, and calibrating result of measurement on the sample on the basis of the calibration standard.

A measuring apparatus comprising;

• a measuring chip consisting of a dielectric block, a film layer formed on one face of the dielectric block and a sample holding system which holds the sample on the surface of the film layer;
• a light source which emits a light beam;
• an optical system which causes the light beam to enter the dielectric block at an angle of incidence such that total internal reflection conditions are satisfied at the interface of the dielectric block and the film layer;
• and a photodetector means which detects the intensity of the light beam reflected in total internal reflection at the interface, wherein the improvement comprises
• a calibrating means which obtains a calibration standard by measuring the refractive indexes of a plurality of reference samples whose refractive indexes are known and calibrates result of measurement on the sample on the basis of the calibration standard.