Surface plasmon resonance sensor

A surface plasmon resonance sensor, comprising:

• an optical waveguide;
• a source of electromagnetic radiation connected to said optical waveguide;
• first and second films coated on each other and on said optical waveguide at a sample contacting region of said optical waveguide, said first and second films having a combined thickness small enough to allow an evanescent field portion of a beam of electromagnetic radiation supplied from said source into said optical waveguide to penetrate into both said first and second films;
• and
• a detector connected to said optical waveguide for detecting surface plasmon resonance as a function of a thickness and refractive index for both said first and second films and a refractive index of said sample.

A biochemical or biological sensor, comprising:

• an optical fiber;
• a source of electromagnetic radiation connected to said optical fiber;
• first and second films coated on each other and on said optical fiber at a sample contacting region of said optical fiber, said first and second films having a combined thickness small enough to allow an evanescent field portion of a beam of electromagnetic radiation supplied from said source into said optical fiber to penetrate into both said first and second films, said first film being a metal or metal alloy film, said second film being selected from the group consisting of dielectric materials, polymeric materials, metals, metal oxides, chalcogenides, semiconductors, organic layers, inorganic layers, and glass materials, said first film being coated on said sample contacting region of said optical fiber and said second film being coated on top of said first film;
• a biomaterial specific for binding an analyte of interest in a sample immobilized on said second film;
• and
• a detector connected to said optical fiber for detecting changes in surface plasmon resonance which occur when said biomaterial binds said analyte of interest in said sample as a function of a thickness and refractive index for both said first and second films.

A corrosion sensor, comprising:

• an optical fiber;
• a source of electromagnetic radiation connected to said optical fiber;
• first and second films coated on each other and on said optical fiber at a sample contacting region of said optical fiber, said first and second films having a combined thickness small enough to allow an evanescent field portion of a beam of electromagnetic radiation supplied from said source into said optical fiber to penetrate into both said first and second films, said first film being a metal or metal alloy;
• a detector connected to said optical fiber for detecting changes in surface plasmon resonance when said metal or metal alloy in said first film corrodes due to exposure to corrosive agents in a sample which contacts said first film, said changes in surface plasmon resonance being a function of a thickness and refractive index for both said first and second films.

A surface plasmon resonance sensor for monitoring effluent from a liquid chromatography or high performance liquid chromotography column, comprising:

• an optical fiber;
• a source of electromagnetic radiation connected to said optical fiber;
• first and second films coated on each other and on said optical fiber at a sample contacting region of said optical fiber, said first and second films having a combined thickness small enough to allow an evanescent field portion of a beam of electromagnetic radiation supplied from said source into said optical fiber to penetrate into both said first and second films;
• means to convey effluent from a liquid chromotography or high performance liquid chromotography column over said sample contacting region of said optical fiber;
• and
• a detector connected to said optical fiber for detecting surface plasmon resonance as a function of a thickness and refractive index for both said first and second films and a refractive index of said effluent.