Development of an Automated Bench-top Biosensor using Novel Gold-Coated Up-Converting Nanoparticles as Labels

A widespread problem facing fluorescent biosensor detection systems is that the biological specimen under study will absorb optical excitation wavelengths selected to only excite a fluorescent label. A need exists for a biosensor that maximizes the signal-to-noise ratio by seeking to avoid the problem of autofluorescence and unwanted sample absorption. This study explains the development and design of an automated optical biosensor and describes the potential benefits of utilizing novel gold-coated up-converting nanoparticle labels in biosensor applications.;The absorption problem is mitigated by the use of an up-converting nanoparticle. Furthermore, the use of a gold shell makes it easier to quantify an analyte of interest that may be present in a biological sample. The viability of novel gold-coated nanoparticles as labels in biosensors and the description of a membrane-based biosensor was evaluated.;The test system can utilize microarray and lateral flow assay formats for fluorescence detection using novel up-converting nanoparticles as labels. It was found that the nanoparticles could be used successfully in an immunoassay for the detection of streptavidin and biotin biomolecules. The biosensor was able to detect molecules down to a concentration level of 0.1 ng/ml. It was found that the immunoassay method and the detection level can potentially be improved by optimizing the conjugation procedures and by improving particle stability.