title: Microimmunoanalysis on standard compact discs to determine low abundant compounds.
abstract: High-density competitive indirect microimmunoassays were performed in both sides of compact discs by direct absorption of immunoreagents on polycarbonate surface, using gold- or enzyme-labeled immunoglobulins as tracers for displaying the immunoreaction. The operational principle is based on the use of a low-reflectivity compact disc as analytical platform that allows the reflection/transmission (30/70%) of the CD reader laser beam (lambda 780 nm). The reflected light is used to scan the disc track keeping it in movement. The transmitted light is detected by a planar photodiode integrated on the CD drive. The variation of the optical transmission of the light caused by the immunoreaction products is related to the sample concentration. As a proof of concept, low abundant compounds, commonly used as pesticides, were detected in a 60-min total assay time, with a limit of detection ranging from 0.02 to 0.62 microg/L for 2,4,5-TP, chlorpyriphos, and metolachlor. The obtained results show the enormous prospective of compact discs in combination with CD players for multiresidue and drug discovery applications.
authors.affiliation: Departamento de Química, Instituto de Química Molecular Aplicada, and Centro de Tecnología Nanofotónica de Valencia, Universidad Politécnica de Valencia, Camino de Vera s/n, 46071 Valencia, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Morais
authors.forename: Javier
authors.initials: J
authors.lastname: Carrascosa
authors.forename: David
authors.initials: D
authors.lastname: Mira
authors.forename: Rosa
authors.initials: R
authors.lastname: Puchades
authors.forename: Angel
authors.initials: A
authors.lastname: Maquieira
mesh_terms: D002138:Calibration; D016250:Compact Disks; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods*; D046228:Microarray Analysis / Q000295:instrumentation / Q000379:methods