The development of immunoassays to four biological threat agents in a bidiffractive grating biosensor.

A critical need exists for a field deployable biosensor to detect environmental infectious agents in collected air samples rapidly, with sensitivity and specificity approaching that of standard laboratory procedures. The ideal sensor would analyze unknown samples in minutes, have programmable operation for unattended sample analysis, and be capable of multiple agent analysis for a number of agents. The goal of this project was to further the development of the bidiffractive grating biosensor (BDG) created through collaboration between Battelle Memorial Institute (BMI), Hoffman LaRoche (HLR), and the Naval Medical Research Command (NMRC). This manuscript details the development, optimization, and evaluation of this device as a potential field deployable biosensor. Well-characterized immunochemical reagents developed by the Biological Defense Research Department (BDRD) at NMRI were employed to develop assays in the BDG. These results were compared to those obtained with antigen capture enzyme linked immunosorbent assays (ELISAs). Four separate antigens were evaluated: Staphylococcus aureus enterotoxin B (SEB), ricin (RIC), Francisella tularensis (FT), and Clostridium botulinum toxin (BOT).