title: Detection of enantiomeric impurities in a simple membrane-based optical immunosensor.
abstract: Currently available methods for the detection of enantiomeric impurities generally require expensive and sophisticated instrumentation. Here, we describe a simple and inexpensive membrane-based chiral immunosensor that allows quantitative determination of chiral analytes up to an enantiomer excess of 99.9%. The experimental setup is based on a competitive reaction between the analyte and a biotin-derivatized analog for the binding sites of a stereoselective antibody, which is immobilized onto a membrane. The antibody-bound analog is detected with peroxidase-conjugated avidin that converts a colorless substrate into an insoluble dye on the membrane surface. The color intensity, which is inversely related to the concentration of analyte in a sample, can be evaluated with standard image analysis programs.
authors.affiliation: Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, USA. ohofst@niu.edu
authors.forename: Oliver
authors.initials: O
authors.lastname: Hofstetter
authors.forename: Jay K
authors.initials: JK
authors.lastname: Hertweck
authors.forename: Heike
authors.initials: H
authors.lastname: Hofstetter
mesh_terms: D000906:Antibodies / Q000737:chemistry*; D001360:Avidin; D001710:Biotin; D003116:Color; D004340:Drug Contamination; D007118:Immunoassay / Q000379:methods*; D008567:Membranes, Artificial; D009195:Peroxidase; D011786:Quality Control; D013237:Stereoisomerism
chemical_list: D000906:Antibodies; D008567:Membranes, Artificial; D001360:Avidin; D001710:Biotin; D009195:Peroxidase