Journal article

Detection of unlabeled oligonucleotide targets using whispering gallery modes in single, fluorescent microspheres

Edin Nuhiji, Paul Mulvaney

SMALL | WILEY-V C H VERLAG GMBH | Published : 2007


The development of an inexpensive, highly sensitive, whispering gallery mode (WGM) based biosensing system is demonstrated. The system comprises a silica microsphere functionalized with a fluorophore and a dense monolayer of single-strand oligonucleotides. The adsorption of the complementary strand causes spectral shifts in the emission spectrum of the microsphere that can be registered using a conventional optical microscope and CCD detector. The system is capable of detecting low-abundance, unlabeled-oligonucleotide targets. The spectral shifts can be used to monitor both the hybridization kinetics and the denaturation of the double-strand DNA at elevated temperatures. The hybridization ap..

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University of Melbourne Researchers