Microimmunoanalysis on standard compact discs to determine low abundant compounds.
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.
Morais
Sergi
S
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.
Carrascosa
Javier
J
Mira
David
D
Puchades
Rosa
R
Maquieira
Angel
A
D002138:Calibration; D016250:Compact Disks; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods*; D046228:Microarray Analysis / Q000295:instrumentation / Q000379:methods