Abstract:
:We have developed a novel, spectroscopic technique for high-sensitivity, label-free DNA quantification. We demonstrate that an optical resonance (whispering gallery mode) excited in a micron-sized silica sphere can be used to detect and measure nucleic acids. The surface of the silica sphere is chemically modified with oligonucleotides. We show that hybridization to the target DNA leads to a red shift of the optical resonance wavelength. The sensitivity of this resonant technique is measured as 6 pg/mm(2) mass loading, higher as compared to most optical single-pass devices such as surface plasmon resonance biosensors. Furthermore, we show that each microsphere can be identified by its unique resonance wavelength. Specific, multiplexed DNA detection is demonstrated by using two microspheres. The multiplexed signal from two microspheres allows us to discriminate a single nucleotide mismatch in an 11-mer oligonucleotide with a high signal-to-noise ratio of 54. This all-photonic whispering gallery mode biosensor can be integrated on a semiconductor chip that makes it an easy to manufacture, analytic component for a portable, robust lab-on-a-chip device.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Vollmer F,Arnold S,Braun D,Teraoka I,Libchaber Adoi
10.1016/S0006-3495(03)74625-6subject
Has Abstractpub_date
2003-09-01 00:00:00pages
1974-9issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(03)74625-6journal_volume
85pub_type
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