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Thermoelectric effect and its dependence on molecular length and sequence in single DNA molecules.

Li Y, Xiang L, Palma JL, Asai Y, Tao N - Nat Commun (2016)

Bottom Line: The thermoelectric effect is small and insensitive to the molecular length in the hopping regime.In contrast, the thermoelectric effect is large and sensitive to the length in the tunnelling regime.We describe the experimental results in terms of hopping and tunnelling charge transport models.

View Article: PubMed Central - PubMed

Affiliation: Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-5801, USA.

ABSTRACT
Studying the thermoelectric effect in DNA is important for unravelling charge transport mechanisms and for developing relevant applications of DNA molecules. Here we report a study of the thermoelectric effect in single DNA molecules. By varying the molecular length and sequence, we tune the charge transport in DNA to either a hopping- or tunnelling-dominated regimes. The thermoelectric effect is small and insensitive to the molecular length in the hopping regime. In contrast, the thermoelectric effect is large and sensitive to the length in the tunnelling regime. These findings indicate that one may control the thermoelectric effect in DNA by varying its sequence and length. We describe the experimental results in terms of hopping and tunnelling charge transport models.

No MeSH data available.


Thermoelectric effect in DNA in terms of tunnelling and hopping models.(a) Charge transport in A(CG)nT, where a hole is injected from left electrode into the first G, then hops along the molecule with each G as a hopping site, and eventually reaches the right electrode. The charge transfer rates at the contacts (red part) are energy dependent, which is a dominant contribution to the Seebeck coefficient. (b) Charge transport in ACGC(AT)mGCGT and ACGC(AT)m−1AGCGT, where a tunnelling barrier (marked blue) arises from the AT block. (c) R × S versus Rh for A(CG)nT sequences. (d) R × S versus Rt for ACGC(AT)mGCGT and ACGC(AT)m−1AGCGT (m=1 and 2). Solid lines in c and d are linear fits to the data.
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f5: Thermoelectric effect in DNA in terms of tunnelling and hopping models.(a) Charge transport in A(CG)nT, where a hole is injected from left electrode into the first G, then hops along the molecule with each G as a hopping site, and eventually reaches the right electrode. The charge transfer rates at the contacts (red part) are energy dependent, which is a dominant contribution to the Seebeck coefficient. (b) Charge transport in ACGC(AT)mGCGT and ACGC(AT)m−1AGCGT, where a tunnelling barrier (marked blue) arises from the AT block. (c) R × S versus Rh for A(CG)nT sequences. (d) R × S versus Rt for ACGC(AT)mGCGT and ACGC(AT)m−1AGCGT (m=1 and 2). Solid lines in c and d are linear fits to the data.

Mentions: We analyse the experimental thermoelectric effect in the hopping regime with equation (3) by assuming that the resistance function, R(E), can be expressed as a sum of the contact and hopping resistance functions (equation (1)), which is modelled as Fig. 5a. Consequently, the overall Seebeck coefficient (S) consists of contributions from the molecule–electrode contact (Sc) and hopping along the dsDNA sequences (Sh), given by


Thermoelectric effect and its dependence on molecular length and sequence in single DNA molecules.

Li Y, Xiang L, Palma JL, Asai Y, Tao N - Nat Commun (2016)

Thermoelectric effect in DNA in terms of tunnelling and hopping models.(a) Charge transport in A(CG)nT, where a hole is injected from left electrode into the first G, then hops along the molecule with each G as a hopping site, and eventually reaches the right electrode. The charge transfer rates at the contacts (red part) are energy dependent, which is a dominant contribution to the Seebeck coefficient. (b) Charge transport in ACGC(AT)mGCGT and ACGC(AT)m−1AGCGT, where a tunnelling barrier (marked blue) arises from the AT block. (c) R × S versus Rh for A(CG)nT sequences. (d) R × S versus Rt for ACGC(AT)mGCGT and ACGC(AT)m−1AGCGT (m=1 and 2). Solid lines in c and d are linear fits to the data.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835548&req=5

f5: Thermoelectric effect in DNA in terms of tunnelling and hopping models.(a) Charge transport in A(CG)nT, where a hole is injected from left electrode into the first G, then hops along the molecule with each G as a hopping site, and eventually reaches the right electrode. The charge transfer rates at the contacts (red part) are energy dependent, which is a dominant contribution to the Seebeck coefficient. (b) Charge transport in ACGC(AT)mGCGT and ACGC(AT)m−1AGCGT, where a tunnelling barrier (marked blue) arises from the AT block. (c) R × S versus Rh for A(CG)nT sequences. (d) R × S versus Rt for ACGC(AT)mGCGT and ACGC(AT)m−1AGCGT (m=1 and 2). Solid lines in c and d are linear fits to the data.
Mentions: We analyse the experimental thermoelectric effect in the hopping regime with equation (3) by assuming that the resistance function, R(E), can be expressed as a sum of the contact and hopping resistance functions (equation (1)), which is modelled as Fig. 5a. Consequently, the overall Seebeck coefficient (S) consists of contributions from the molecule–electrode contact (Sc) and hopping along the dsDNA sequences (Sh), given by

Bottom Line: The thermoelectric effect is small and insensitive to the molecular length in the hopping regime.In contrast, the thermoelectric effect is large and sensitive to the length in the tunnelling regime.We describe the experimental results in terms of hopping and tunnelling charge transport models.

View Article: PubMed Central - PubMed

Affiliation: Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-5801, USA.

ABSTRACT
Studying the thermoelectric effect in DNA is important for unravelling charge transport mechanisms and for developing relevant applications of DNA molecules. Here we report a study of the thermoelectric effect in single DNA molecules. By varying the molecular length and sequence, we tune the charge transport in DNA to either a hopping- or tunnelling-dominated regimes. The thermoelectric effect is small and insensitive to the molecular length in the hopping regime. In contrast, the thermoelectric effect is large and sensitive to the length in the tunnelling regime. These findings indicate that one may control the thermoelectric effect in DNA by varying its sequence and length. We describe the experimental results in terms of hopping and tunnelling charge transport models.

No MeSH data available.