New Microarray Slides Capable of Enhancing Fluorescence

Microarrays are typically analyzed using a biomolecule conjugated to a fluorescent probe. Although this method works well, no signal amplification is possible with this general approach. Plasmonix Inc has taken advantage of a well known phenomenon called Metal Enhanced Fluorescence (MEF) to develop a new microarray slide which incorporates this technology and enhances fluorescent signals by approximately 30-fold. These new slides, called QuantArray slides, are glass slides with a thin layer of metal nanoparticles covered by a silica layer and finally a coat of epoxy silane. The epoxy silane promotes strong adherence of proteins. To demonstrate that QuantaArray slides enhance fluorescence, we coated either QuantArray slides or plain glass slides with the same epoxy silane coating with varying concentrations of biotinylated-BSA. The biotinylated BSA was detected with strepatividin-conjugated DL633 dye and read in a standard slide reader. We found that QuantArray slides could easily detect a spot of 0.006 pg of Bt-BSA, whereas the control slides could barely detect a spot of 0.06 pg of Bt-BSA demonstrating an approximately 30 fold enhancement of the signal. Background staining was negligible. These slides will be useful in proteomics assays requiring an enhanced fluorescent signal.