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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 measurement of DNA.(a) Semi-logarithmic plot of conductance–distance trace (the coloured dots mark, where I–V curves are measured). (b) Individual I–V curves measured at the locations marked with corresponding colour in a. (c) I/G–V histogram at ΔT=0 K. (d) I/G–V histogram at ΔT=19.5 K, showing an offset due to the thermoelectric effect. (e) Thermal voltage histogram, where the red curves show Gaussian fits. (f) Thermoelectric voltage versus ΔT, where the straight line is linear fit to the data, and error bars are fitting errors. DNA sequence: ACGC(AT)2GCGT.
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f3: Thermoelectric measurement of DNA.(a) Semi-logarithmic plot of conductance–distance trace (the coloured dots mark, where I–V curves are measured). (b) Individual I–V curves measured at the locations marked with corresponding colour in a. (c) I/G–V histogram at ΔT=0 K. (d) I/G–V histogram at ΔT=19.5 K, showing an offset due to the thermoelectric effect. (e) Thermal voltage histogram, where the red curves show Gaussian fits. (f) Thermoelectric voltage versus ΔT, where the straight line is linear fit to the data, and error bars are fitting errors. DNA sequence: ACGC(AT)2GCGT.

Mentions: The thermoelectric effect measurement started by detecting plateaus in the conductance traces during the retraction of the STM tip from the substrate (Fig. 3a). Once a plateau was detected, the tip retraction was halted and the bias voltage between the tip and substrate electrodes was swept over ±10 mV to obtain a current (I)–voltage (V) characteristic curve. After recording an I–V curve, the tip was further retracted to a new position, and the I–V measurement was repeated until the molecular junction broke down. Figure 3b shows several I–V curves for ACGC(AT)2GCGT measured at different locations of a conductance plateau, where the colours of curves match the colours of the dots marked on the conductance plateau shown in Fig. 3a. These I–V curves are linear within the bias range.


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 measurement of DNA.(a) Semi-logarithmic plot of conductance–distance trace (the coloured dots mark, where I–V curves are measured). (b) Individual I–V curves measured at the locations marked with corresponding colour in a. (c) I/G–V histogram at ΔT=0 K. (d) I/G–V histogram at ΔT=19.5 K, showing an offset due to the thermoelectric effect. (e) Thermal voltage histogram, where the red curves show Gaussian fits. (f) Thermoelectric voltage versus ΔT, where the straight line is linear fit to the data, and error bars are fitting errors. DNA sequence: ACGC(AT)2GCGT.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f3: Thermoelectric measurement of DNA.(a) Semi-logarithmic plot of conductance–distance trace (the coloured dots mark, where I–V curves are measured). (b) Individual I–V curves measured at the locations marked with corresponding colour in a. (c) I/G–V histogram at ΔT=0 K. (d) I/G–V histogram at ΔT=19.5 K, showing an offset due to the thermoelectric effect. (e) Thermal voltage histogram, where the red curves show Gaussian fits. (f) Thermoelectric voltage versus ΔT, where the straight line is linear fit to the data, and error bars are fitting errors. DNA sequence: ACGC(AT)2GCGT.
Mentions: The thermoelectric effect measurement started by detecting plateaus in the conductance traces during the retraction of the STM tip from the substrate (Fig. 3a). Once a plateau was detected, the tip retraction was halted and the bias voltage between the tip and substrate electrodes was swept over ±10 mV to obtain a current (I)–voltage (V) characteristic curve. After recording an I–V curve, the tip was further retracted to a new position, and the I–V measurement was repeated until the molecular junction broke down. Figure 3b shows several I–V curves for ACGC(AT)2GCGT measured at different locations of a conductance plateau, where the colours of curves match the colours of the dots marked on the conductance plateau shown in Fig. 3a. These I–V curves are linear within the bias range.

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.