Optimization of surface plasmon resonance for environmental monitoring

A novel architecture for using surface plasmon resonance (SPR) for environmental monitoring is presented that reduces the key barriers (cost, size, weight, and power consumption) for entry into portable environmental monitoring markets. The novelty of the system emphasizes the electronic rather than optical capture of the point of resonance in a liquid sensing medium. The instrument presented herein eliminates the spectrometer (also the bulk of the cost) and instead uses electronic (overdrive) control of the light source to enable fine shifts in the wavelength of the input spectrum. These fine, electronically controlled spectral shifts provide comparable discernment to optical spectrometer-based methods in identifying refractive index using the point of SPR. The total cost of the new system is approximately an order of magnitude (hundreds rather than thousands of dollars) less than spectrometer-based systems and provides comparable or improved performance in accuracy, resolution, stability, and drift (repeatability).