TY - JOUR
T1 - Two-color spectroscopy of UV excited ssDNA complex with a single-wall nanotube photoluminescence probe
T2 - Fast relaxation by nucleobase autoionization mechanism
AU - Ignatova, Tetyana
AU - Balaeff, Alexander
AU - Blades, Michael
AU - Zheng, Ming
AU - Stoeckl, Peter
AU - Rotkin, Slava V.
N1 - Publisher Copyright:
© 2015, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.
PY - 2016/2/1
Y1 - 2016/2/1
N2 - DNA autoionization is a fundamental process wherein ultraviolet (UV)-photoexcited nucleobases dissipate energy by charge transfer to the environment without undergoing chemical damage. Here, single-wall carbon nanotubes (SWNT) are explored as a photoluminescent reporter for the study of the mechanism and rates of DNA autoionization. Two-color photoluminescence spectroscopy allows separate photoexcitation of the DNA and the SWNTs in the UV and visible range, respectively. A strong SWNT photoluminescence quenching is observed when the UV pump is resonant with the DNA absorption, consistent with charge transfer from the excited states of the DNA to the SWNT. Semiempirical calculations of the DNA-SWNT electronic structure, combined with a Green’s function theory for charge transfer, show a 20 fs autoionization rate, dominated by hole transfer. Rate-equation analysis of the spectroscopy data confirms that the quenching rate is limited by thermalization of the free charge carriers transferred to the nanotube reservoir. This approach has great potential for monitoring DNA excitation, autoionization, and chemical damage, both in vivo and in vitro. [Figure not available: see fulltext.]
AB - DNA autoionization is a fundamental process wherein ultraviolet (UV)-photoexcited nucleobases dissipate energy by charge transfer to the environment without undergoing chemical damage. Here, single-wall carbon nanotubes (SWNT) are explored as a photoluminescent reporter for the study of the mechanism and rates of DNA autoionization. Two-color photoluminescence spectroscopy allows separate photoexcitation of the DNA and the SWNTs in the UV and visible range, respectively. A strong SWNT photoluminescence quenching is observed when the UV pump is resonant with the DNA absorption, consistent with charge transfer from the excited states of the DNA to the SWNT. Semiempirical calculations of the DNA-SWNT electronic structure, combined with a Green’s function theory for charge transfer, show a 20 fs autoionization rate, dominated by hole transfer. Rate-equation analysis of the spectroscopy data confirms that the quenching rate is limited by thermalization of the free charge carriers transferred to the nanotube reservoir. This approach has great potential for monitoring DNA excitation, autoionization, and chemical damage, both in vivo and in vitro. [Figure not available: see fulltext.]
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U2 - 10.1007/s12274-015-0938-0
DO - 10.1007/s12274-015-0938-0
M3 - Article
AN - SCOPUS:84958112530
SN - 1998-0124
VL - 9
SP - 571
EP - 583
JO - Nano Research
JF - Nano Research
IS - 2
ER -