Protein Array Detection with Nanoparticle Fluorescent Probes by Laser Confocal Scanning Fluorescence Detection

Abstract

The new and versatile protein microarray technology allows high-throughput screening for gene expression, drug screening and disease detection. An protein microarray using antibodies modified by ZnS-coated CdSe quantum dot (ZnS/CdSe QDs) nanoparticle and detected with a conventional laser confocal scanner is described here. Antibody targets labeled with fluorescent QDs rather than organic fluorophore probes have many desirable properties. The fluorescent signals of the sandwich immunoassay conjugate were detected by a laser confocal scanner. A diode laser was used to excite the fluorescent signals efficiently while bovine serum albumin was used to eliminating nonspecific binding sites. The specificity of the QDs-labeled immunoglobulin (IgG) was tested in an experiment using goat IgG and human IgG samples. The result was consistent with the binding specificity in a sandwich-type assay. The potential of this method to function as a simple and efficient readout strategy for microarray is discussed.