TY - JOUR
T1 - Two-step energy transfer dynamics in conjugated polymer and dye-labeled aptamer-based potassium ion detection assay
AU - Kim, Inhong
AU - Jung, Ji Eun
AU - Lee, Woojin
AU - Park, Seongho
AU - Kim, Heedae
AU - Jho, Young Dahl
AU - Woo, Han Young
AU - Kyhm, Kwangseuk
N1 - Funding Information:
Funding: This research was supported by a two-year research grant from Pusan National University.
Publisher Copyright:
© 2019 by the authors.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/7/1
Y1 - 2019/7/1
N2 - We recently implemented highly sensitive detection systems for photo-sensitizing potassium ions (K+) based on two-step Förster resonance energy transfer (FRET). As a successive study for quantitative understanding of energy transfer processes in terms of the exciton population, we investigated the fluorescence decay dynamics in conjugated polymers and an aptamer-based 6-carboxyfluorescein (6-FAM)/6-carboxytetramethylrhodamine (TAMRA) complex. In the presence of K+ ions, the Guanine-rich aptamer enabled efficient two-step resonance energy transfer from conjugated polymers to dyed pairs of 6-FAMand TAMRAthrough the G-quadruplex phase. Although the fluorescence decay time of TAMRA barely changed, the fluorescence intensity was significantly increased. We also found that 6-FAM showed a decreased exciton population due the compensation of energy transfer to TAMRA by FRET from conjugated polymers, but a fluorescence quenching also occurred concomitantly. Consequently, the fluorescence intensity of TAMRA showed a 4-fold enhancement, where the initial transfer efficiency (~300%) rapidly saturated within ~0.5 ns and the plateau of transfer efficiency (~230%) remained afterward.
AB - We recently implemented highly sensitive detection systems for photo-sensitizing potassium ions (K+) based on two-step Förster resonance energy transfer (FRET). As a successive study for quantitative understanding of energy transfer processes in terms of the exciton population, we investigated the fluorescence decay dynamics in conjugated polymers and an aptamer-based 6-carboxyfluorescein (6-FAM)/6-carboxytetramethylrhodamine (TAMRA) complex. In the presence of K+ ions, the Guanine-rich aptamer enabled efficient two-step resonance energy transfer from conjugated polymers to dyed pairs of 6-FAMand TAMRAthrough the G-quadruplex phase. Although the fluorescence decay time of TAMRA barely changed, the fluorescence intensity was significantly increased. We also found that 6-FAM showed a decreased exciton population due the compensation of energy transfer to TAMRA by FRET from conjugated polymers, but a fluorescence quenching also occurred concomitantly. Consequently, the fluorescence intensity of TAMRA showed a 4-fold enhancement, where the initial transfer efficiency (~300%) rapidly saturated within ~0.5 ns and the plateau of transfer efficiency (~230%) remained afterward.
KW - FRET
KW - Potassium ion detection
KW - Time-resolved photoluminescence
KW - Two-step FRET
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U2 - 10.3390/polym11071206
DO - 10.3390/polym11071206
M3 - Article
AN - SCOPUS:85070391832
VL - 11
JO - Polymers
JF - Polymers
SN - 2073-4360
IS - 7
M1 - 1206
ER -