Enhancing the surface sensitivity of colorimetric resonant optical biosensors

Through alteration of the structure of a colorimetric resonant optical biosensor, the relative contribution of surface-binding effects to bulk refractive index effects can be influenced to favor detection of material in direct proximity to the sensor surface structure. The sequential buildup of polyelectrolyte monolayers has been used as a characterization method for determining the sensitivity of the device as a function of deposited thickness in an aqueous environment. A subtle change in the sensor structure is found to enhance surface sensitivity by ∼4.5 ×.