302
T. Ishi-i
8.4 Conclusions
In this chapter, we summarized fluorescent TPA dyes that emit red and near-IR light
and the recent advances made in their development for applications in biological
systems. The TPA nature is ascribed to the intramolecular charge transfer characteristic arising from the conjugation of electron–donor, electron–acceptor, and π-spacer
moieties. The fluorescence efficiency can be improved by using the aggregationinduced emission concept, leading to enhanced light-emitting systems. The red and
near-IR light emission of longer wavelength can be achieved by elongated π-systems
and/or an enhanced intramolecular charge transfer nature. The created fluorescent
TPA dyes can be developed for biological monitoring of fluoride ions, sulfur dioxide,
nitrogen oxide, carbon monoxide, and hydrogen sulfide as well as for biological
imaging of mitochondria, amyloid-β plaques, biotin receptors, mouse brain slices,
and plasma membranes. The success of these biological applications is based on the
combined effect of near-IR two-photon excitation and red/near-IR fluorescence emission because both excitation and emission processes can be performed in the biological optical window, providing versatile advantages, such as reduced autofluorescence and deeper penetration in tissues, less photodamage and photobleaching, and
a higher three-dimensional resolution. The two-photon excited fluorescent technique
will contribute further to the elucidation of living systems and disease diagnosis.
References
Albota M, Beljonne D, Brédas J-L, Ehrlich JE, Fu J-Y, Heikal AA, Hess SE, Kogej T, Levin MD,
Marder SR, McCord-Maughon D, Perry JW, Röckel H, Rumi M, Subramaniam G, Webb WW, Wu
X-L, Xu C (1998) Design of organic molecules with large two-photon absorption cross sections.
Science 281:1653
Berezin MY, Zhan C, Lee H, Joo C, Akers WJ, Yazdanfar S, Achilefu S (2011) Two-photon optical
properties of near-infrared dyes at 1.55 μm excitation. J Phys Chem B 115:11530
Brousmiche DW, Serin JM, Fréchet JMJ, He GS, Lin T-C, Chung S-J, Prasad PN (2003) Fluorescence resonance energy transfer in a novel two-photon absorbing system. J Am Chem Soc
125:1448
Brousmiche DW, Serin JM, Fréchet JMJ, He GS, Lin T-C, Chung S-J, Prasad PN, Kannan R, Tan
L-S (2004) Fluorescence resonance energy transfer in novel multiphoton absorbing dendritic
structures. J Phys Chem B 108:8592
Chen X, Wang F, Hyun JY, Wei T, Qiang J, Ren X, Shin I, Yoon J (2016) Recent progress in the
development of fluorescent, luminescent and colorimetric probes for detection of reactive oxygen
and nitrogen species. Chem Soc Rev 45:2976
Cumpston BH, Ananthavel SP, Barlow S, Dyer DL, Ehrlich JE, Erskine LL, Heikal AA, Kuebler
SM, Lee I-YS, McCord-Maughon D, Qin J, Röckel H, Rumi M, Wu XL, Marder SR, Perry
JW (1999) Two-photon polymerization initiators for three-dimensional optical data storage and
microfabrication. Nature 398:51
Denk W, Strickers JH, Webb WW (1990) Two-photon laser scanning fluorescence microscopy.
Science 248:73
T. Ishi-i
8.4 Conclusions
In this chapter, we summarized fluorescent TPA dyes that emit red and near-IR light
and the recent advances made in their development for applications in biological
systems. The TPA nature is ascribed to the intramolecular charge transfer characteristic arising from the conjugation of electron–donor, electron–acceptor, and π-spacer
moieties. The fluorescence efficiency can be improved by using the aggregationinduced emission concept, leading to enhanced light-emitting systems. The red and
near-IR light emission of longer wavelength can be achieved by elongated π-systems
and/or an enhanced intramolecular charge transfer nature. The created fluorescent
TPA dyes can be developed for biological monitoring of fluoride ions, sulfur dioxide,
nitrogen oxide, carbon monoxide, and hydrogen sulfide as well as for biological
imaging of mitochondria, amyloid-β plaques, biotin receptors, mouse brain slices,
and plasma membranes. The success of these biological applications is based on the
combined effect of near-IR two-photon excitation and red/near-IR fluorescence emission because both excitation and emission processes can be performed in the biological optical window, providing versatile advantages, such as reduced autofluorescence and deeper penetration in tissues, less photodamage and photobleaching, and
a higher three-dimensional resolution. The two-photon excited fluorescent technique
will contribute further to the elucidation of living systems and disease diagnosis.
References
Albota M, Beljonne D, Brédas J-L, Ehrlich JE, Fu J-Y, Heikal AA, Hess SE, Kogej T, Levin MD,
Marder SR, McCord-Maughon D, Perry JW, Röckel H, Rumi M, Subramaniam G, Webb WW, Wu
X-L, Xu C (1998) Design of organic molecules with large two-photon absorption cross sections.
Science 281:1653
Berezin MY, Zhan C, Lee H, Joo C, Akers WJ, Yazdanfar S, Achilefu S (2011) Two-photon optical
properties of near-infrared dyes at 1.55 μm excitation. J Phys Chem B 115:11530
Brousmiche DW, Serin JM, Fréchet JMJ, He GS, Lin T-C, Chung S-J, Prasad PN (2003) Fluorescence resonance energy transfer in a novel two-photon absorbing system. J Am Chem Soc
125:1448
Brousmiche DW, Serin JM, Fréchet JMJ, He GS, Lin T-C, Chung S-J, Prasad PN, Kannan R, Tan
L-S (2004) Fluorescence resonance energy transfer in novel multiphoton absorbing dendritic
structures. J Phys Chem B 108:8592
Chen X, Wang F, Hyun JY, Wei T, Qiang J, Ren X, Shin I, Yoon J (2016) Recent progress in the
development of fluorescent, luminescent and colorimetric probes for detection of reactive oxygen
and nitrogen species. Chem Soc Rev 45:2976
Cumpston BH, Ananthavel SP, Barlow S, Dyer DL, Ehrlich JE, Erskine LL, Heikal AA, Kuebler
SM, Lee I-YS, McCord-Maughon D, Qin J, Röckel H, Rumi M, Wu XL, Marder SR, Perry
JW (1999) Two-photon polymerization initiators for three-dimensional optical data storage and
microfabrication. Nature 398:51
Denk W, Strickers JH, Webb WW (1990) Two-photon laser scanning fluorescence microscopy.
Science 248:73