Sensitivity Optimization of Plain Silver Surface Plasmon Resonance Imaging Sensor
Abstract Plain silver surface plasmon resonance imaging (SPRi) sensor has been studied extensively due to its high sensitivity and desirable stability in liquid environments. To further enhance sensitivity performance of the sensor, angular sensitivity, angular slope and depth-width ratio (DWR) of SPR curve, and imaging sensitivity are evaluated at different thickness combinations of the gold and silver films respectively. In this work, the angular slope of SPR curve is found to be the critical factor to the optimized imaging sensitivity of plain silver SPRi sensor. In the comparative study, the above parameters of the plain silver SPR sensor, single gold film and bimetallic SPRi sensors are compared. Plain silver SPRi sensor is proved to be of the highest imaging sensitivity, which is 4.08 and 1.18 times imaging sensitivity of the single gold film and bimetallic SPRi sensors separately.
