A liquid crystal pixel array for signal discrimination in array biosensors

A new optical design uses a liquid crystal pixel array (LCPA) to discriminate multiple fluorescence signals on a two-dimensional biosensor array. The LCPA can selectively control the transmission of fluorescence generated from multiple biosensing elements on a planar waveguide. This device sequentially acquires the fluorescence data from the substrate by making multiple individual measurements of the sensing elements on the waveguide. The biosensing elements are patterned according to the pixel layout of the LCPA and optically aligned so that each electronically driven pixel can either transmit or filter out the fluorescence signal as specified by the user. The primary advantage of this system is that a single detection channel (i.e. photomultiplier tube (PMT)) can be used to measure multiple fluorescence signals from a two-dimensional substrate while the LCPA provides for spatial resolution. We evaluate the performance of the LCPA by testing the optical homogeneity of the liquid crystal pixels and linear dynamic range for transmitting light. The LCPA is also used with well-developed biosensing chemistry modified for this optical format.