A Holographic Biosensor

The concept of using a hologram as the interactive element in a one-shot biosensor is presented. The theoretical basis for a directly-observed optical response to biological molecules is introduced. The device as described is relevant to low-cost screening for pancreatic disorders by detection of less than 250nM trypsin in duodenal fluid or stool sample [1]. Data is shown for response of a gelatin-based reflection hologram to the serine proteases trypsin and chymotrypsin presented in pure form or in pancreatin. Specificity to detection of trypsin is shown to be feasible by judicious use of a bovine pancreatic trypsin inhibitor (BPTI). Extension of the concept to other enzymes is introduced.