System-on-chip surface plasmon resonance sensors using pulse-based interface circuits

A pulse-based interface circuit for surface plasmon resonance (SPR) sensing systems has been designed and fabricated to transform SPR sensing information into a single voltage directly correlated to refractive index by computing weighted sums of SPR spectral components. The interface circuit has the ability to perform parametric regression on SPR spectral components through pulse-based multiplication. This technique provides an advantage over previous designs; the interface circuit computes a weighted sum of spectral components rather than sum alone. Results for the optimizing pulse-based interface circuit indicate a significant increase in correlation coefficient between the actual refractive index and the predicted