Surface plasmon resonance chemical electrode

A method for detecting redox-active and redox-inactive analytes in a sample, comprising the steps of:

• (a) contacting the sample with a first sensing area of a surface plasmon resonance sensor device, said device comprising:
• a surface plasmon resonance sensor comprising an optical fiber having a core and a cladding layer surrounding the core, wherein the optical fiber has a first end and a second end and has a first sensing area located between the first end and the second end or at the second end, wherein the first sensing area is defined by a conducting film in contact with at least a portion of a surface of the core free from the surrounding cladding layer;
• a light source optically coupled to the first end of the sensor such that light propagates by total internal reflection from the first end towards the second end and excites surface plasmon resonance;
• a voltage source electrically coupled to the first sensing area for selectively applying a constant or variable voltage to the first sensing area;
• and
• a detector for monitoring a surface plasmon resonance signal exiting the surface plasmon resonance sensor as a function of voltage applied to the first sensing area;
• (b) introducing light into the surface plasmon resonance sensor whereby the light undergoes total internal reflection therein;
• (c) applying a voltage to the first sensing area;
• (d) measuring the surface plasmon resonance signal exiting the surface plasmon resonance sensor during or after application of the voltage to detect redox-inactive analytes;
• and
• (e) measuring current resulting from application of the voltage or the surface plasmon resonance signal exiting the surface plasmon resonance sensor during or after application of the voltage to detect redox-active analytes.

A method for detecting intermetallic compound analytes, in a sample, comprising the steps of:

• (a) contacting the sample with a first sensing area of a surface plasmon resonance sensor device, said device comprising:
• a surface plasmon resonance sensor comprising an optical fiber having a core and a cladding layer surrounding the core, wherein the optical fiber has a first end and a second end and has a first sensing area located between the first end and the second end or at the second end, wherein the first sensing area is defined by a conducting film in contact with at least a portion of a surface of the core free from the surrounding cladding layer;
• a light source optically coupled to the first end of the sensor such that light propagates by total internal reflection from the first end towards the second end and excites surface plasmon resonance;
• a voltage source electrically coupled to the first sensing area for selectively applying a constant or variable voltage to the first sensing area;
• and
• a detector for monitoring a surface plasmon resonance signal exiting the surface plasmon resonance sensor as a function of voltage applied to the first sensing area;
• (b) introducing light into the surface plasmon resonance sensor whereby the light undergoes total internal reflection therein;
• (c) applying a voltage to the first sensing area;
• and
• (d) measuring the surface plasmon resonance signal exiting the surface plasmon resonance sensor during or after application of the voltage to detect intermetallic compound analytes.