(242b) Screening of Recombinant Scfvs as Immuno-Agents for Small Molecule Detection

Monitoring small molecules has drawn great attention in the field of environmental monitoring, health care and homeland security due to its impact on the human life. To detect these small compounds, we have proposed a displacement format of immunosensor with high sensitivity and selectivity. In order to further improve the sensitivity of the sensor, a new generation of single chain antibody fragments (scFvs) with enhanced displacement properties in the presence of the target analyte was selected using a yeast surface display library. Atrazine, a major herbicide in the agricultural field, was chosen as a model small molecule. Using fluorescence activated cell sorter (FACS), we first screened scFvs with high affinity toward both atrazine and its analogy simazine. The selected scFv library, was first incubated with Alexa-labeled simazine, and then subjected to displacement screening in the presence of varying concentrations of atrazine. After 4 rounds of displacement, several scFvs which showed a substantial displacement of the Alexa-labeled simazine, were identified. This study demonstrates a new screening strategy to develop recombinant scFvs for small molecule detection using the displacement format.