TY - GEN
T1 - DMSO effects on FRET to dye-labeled DNA in conjugated polymer-based DNA detection
AU - Kang, Mijeong
AU - Kim, Boram
AU - Woo, Han Young
PY - 2011
Y1 - 2011
N2 - Solvent effects were studied in fluorescence resonance energy transfer (FRET) from a cationic polyfluorene copolymer (FHQ, FPQ) to a fluorescein (Fl)-labeled oligonucleotide (ssDNA-Fl). Upon addition of dimethyl sulfoxide (DMSO), optical properties of the polymers and the probe dye were substantially modified. And the FRET-induced Fl emission was measured by directly exciting the polymer within the complex, polymer/ssDNA-Fl. The FRET signal was successfully modulated with changing the DMSO content. In the case of FHQ, the FRET-induced Fl emission was seriously quenched in phosphate buffer solution (PBS), while a salient FRET signal was observed in a 80 vol% DMSO/PBS mixture (36.8 time higher than that in PBS). The FPQ-sensitized FRET signal was also 3.8-fold amplified by the presence of DMSO. That result is from the decrease of hydrophobic interactions between the polymer and ssDNA-Fl, which induces the weaker polymer/ssDNA-Fl complexation with longer intermolecular separation. The gradual decrease in Fl PL quenching with increasing the DMSO content was investigated by measuring the Stern- Volmer quenching constants (3.3-4.2 × 10 6 M-1 in PBS, 0.56-1.1 x 106 M-1 in 80 vol% DMSO) in PBS/DMSO mixtures. The substantially reduced PL quenching would amplify the resulting FRET Fl signal. This approach suggests a simple way of modifying the fine-structure of polymer/ssDNA-Fl and improving the detection sensitivity in conjugated polymer-based FRET bioassays.
AB - Solvent effects were studied in fluorescence resonance energy transfer (FRET) from a cationic polyfluorene copolymer (FHQ, FPQ) to a fluorescein (Fl)-labeled oligonucleotide (ssDNA-Fl). Upon addition of dimethyl sulfoxide (DMSO), optical properties of the polymers and the probe dye were substantially modified. And the FRET-induced Fl emission was measured by directly exciting the polymer within the complex, polymer/ssDNA-Fl. The FRET signal was successfully modulated with changing the DMSO content. In the case of FHQ, the FRET-induced Fl emission was seriously quenched in phosphate buffer solution (PBS), while a salient FRET signal was observed in a 80 vol% DMSO/PBS mixture (36.8 time higher than that in PBS). The FPQ-sensitized FRET signal was also 3.8-fold amplified by the presence of DMSO. That result is from the decrease of hydrophobic interactions between the polymer and ssDNA-Fl, which induces the weaker polymer/ssDNA-Fl complexation with longer intermolecular separation. The gradual decrease in Fl PL quenching with increasing the DMSO content was investigated by measuring the Stern- Volmer quenching constants (3.3-4.2 × 10 6 M-1 in PBS, 0.56-1.1 x 106 M-1 in 80 vol% DMSO) in PBS/DMSO mixtures. The substantially reduced PL quenching would amplify the resulting FRET Fl signal. This approach suggests a simple way of modifying the fine-structure of polymer/ssDNA-Fl and improving the detection sensitivity in conjugated polymer-based FRET bioassays.
KW - DNA detection
KW - Fluorescence resonance energy transfer (FRET)
KW - conjugated polymers (CPs)
KW - dimethyl sulfoxide (DMSO)
UR - http://www.scopus.com/inward/record.url?scp=79953154052&partnerID=8YFLogxK
U2 - 10.1117/12.874398
DO - 10.1117/12.874398
M3 - Conference contribution
AN - SCOPUS:79953154052
SN - 9780819484451
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications VIII
T2 - Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications VIII
Y2 - 24 January 2011 through 27 January 2011
ER -