Optical Techniques
One such example is that of liquid crystal (LC) based optical sensor for highly sensitive endotoxin detection. LC based optical biosensors are developed using endotoxin specific single-stranded DNA aptamers which are the endotoxin selective probes of the biosensors. The LC based aptamer optical biosensors have linear endotoxin detection range from 0.005 to 100 ng/ml and a detection limit of 5.5 pg/ml. The biosensors have negligible cross-binding reactivity with the biomolecules thus maximizing their recovery 94. Broadly, these optical techniques can be divided into three distinct categories: luminescence, Surface Plasmon Resonance, and electrochemiluminescence that share the similar characteristic of relying on visual changes.