Hydrophobic copper thin film for surface plasmon resonance-based sensor

A surface plasmon resonance sensor system, comprising:

• a sensor plate having a first side and a second side, wherein the second side is opposite the first side, wherein the sensor plate includes:
• a quartz glass substrate, and
• an annealed cuprous oxide film formed by sputtering a copper film onto the quartz glass substrate then annealing the copper film at a temperature of from about 400° C. to about 600° C. for about two hours to convert the copper film to the annealed cuprous oxide film having a refractive index of about 3.05 to about 3.11, an energy band gap Eg of 1.54 to 1.69 eV and a surface with a wetting contact angle of 42.3° to 85.2°;
• a quartz prism having a base surface attached to the first side of sensor plate against the quartz glass substrate;
• a microfluidics unit attached to the second side of the sensor plate against the annealed cuprous oxide film, wherein the microfluidics unit includes a fluid reservoir having an inlet port and an outlet port, wherein the fluid reservoir contains a carrier fluid;
• a target analyte reservoir containing a target analyte;
• a pump connected between the target analyte reservoir and the inlet port, wherein the pump is configured to inject the target analyte into the microfluidics unit through the inlet port;
• a binder attached to the annealed cuprous oxide film, wherein the binder is configured to attach to the target analyte;
• a laser configured to transmit a laser beam into a face of the quartz prism at an incident angle configured to generate surface plasmons which resonate with the annealed cuprous oxide film and reflect a phase shifted laser beam from the annealed cuprous oxide film;
• receive optics configured to receive the phase shifted laser beam;
• a charge coupled device coupled to the receive optics, wherein the charge coupled device is configured to convert the phase shifted laser beam to an electrical signal;
• and
• a computing unit including an electrical circuitry, a memory storing program instructions and at least one processor configured to execute the program instructions, wherein the computing unit is configured to receive the electrical signal and compute a refractive index based on the phase shift, wherein a change in the refractive index is configured to indicate detection of the target analyte.