TY - JOUR
T1 - Single-Walled Carbon Nanotubes Probed with Insulator-Based Dielectrophoresis
AU - Rabbani, Mohammad Towshif
AU - Schmidt, Christoph F.
AU - Ros, Alexandra
N1 - Funding Information:
We thank Robert Ros, Arizona State University, for helpful discussions on SWNT AFM imaging and Mitja Platen, University of Göttingen, for technical help. The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC Grant Agreement No. 340528. Further support came from the Cluster of Excellence and DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB). We gratefully acknowledge further financial support from the Alexander-von-Humboldt Foundation, Germany, through a fellowship awarded to A.R. and from the National Science Foundation (USA) Project No. 1149015 and Supplement No. 1444430 by the Chemical and Biological Separations Program in the Chemical, Environmental, Bioengineering, and Transport Systems Division and the Chemical Measurement and Imaging Program in Mathematical and Physical Sciences.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/12/19
Y1 - 2017/12/19
N2 - Single-walled carbon nanotubes (SWNTs) offer unique electrical and optical properties. Common synthesis processes yield SWNTs with large length polydispersity (several tens of nanometers up to centimeters) and heterogeneous electrical and optical properties. Applications often require suitable selection and purification. Dielectrophoresis is one manipulation method for separating SWNTs based on dielectric properties and geometry. Here, we present a study of surfactant and single-stranded DNA-wrapped SWNTs suspended in aqueous solutions manipulated by insulator-based dielectrophoresis (iDEP). This method allows us to manipulate SWNTs with the help of arrays of insulating posts in a microfluidic device around which electric field gradients are created by the application of an electric potential to the extremities of the device. Semiconducting SWNTs were imaged during dielectrophoretic manipulation with fluorescence microscopy making use of their fluorescence emission in the near IR. We demonstrate SWNT trapping at low-frequency alternating current (AC) electric fields with applied potentials not exceeding 1000 V. Interestingly, suspended SWNTs showed both positive and negative dielectrophoresis, which we attribute to their ζ potential and the suspension properties. Such behavior agrees with common theoretical models for nanoparticle dielectrophoresis. We further show that the measured ζ potentials and suspension properties are in excellent agreement with a numerical model predicting the trapping locations in the iDEP device. This study is fundamental for the future application of low-frequency AC iDEP for technological applications of SWNTs.
AB - Single-walled carbon nanotubes (SWNTs) offer unique electrical and optical properties. Common synthesis processes yield SWNTs with large length polydispersity (several tens of nanometers up to centimeters) and heterogeneous electrical and optical properties. Applications often require suitable selection and purification. Dielectrophoresis is one manipulation method for separating SWNTs based on dielectric properties and geometry. Here, we present a study of surfactant and single-stranded DNA-wrapped SWNTs suspended in aqueous solutions manipulated by insulator-based dielectrophoresis (iDEP). This method allows us to manipulate SWNTs with the help of arrays of insulating posts in a microfluidic device around which electric field gradients are created by the application of an electric potential to the extremities of the device. Semiconducting SWNTs were imaged during dielectrophoretic manipulation with fluorescence microscopy making use of their fluorescence emission in the near IR. We demonstrate SWNT trapping at low-frequency alternating current (AC) electric fields with applied potentials not exceeding 1000 V. Interestingly, suspended SWNTs showed both positive and negative dielectrophoresis, which we attribute to their ζ potential and the suspension properties. Such behavior agrees with common theoretical models for nanoparticle dielectrophoresis. We further show that the measured ζ potentials and suspension properties are in excellent agreement with a numerical model predicting the trapping locations in the iDEP device. This study is fundamental for the future application of low-frequency AC iDEP for technological applications of SWNTs.
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U2 - 10.1021/acs.analchem.7b03105
DO - 10.1021/acs.analchem.7b03105
M3 - Article
C2 - 29131586
AN - SCOPUS:85038807633
SN - 0003-2700
VL - 89
SP - 13235
EP - 13244
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 24
ER -