Optical properties of DNA-CTMA biopolymers and applications in metal-biopolymer-metal photodetectors

Bin Zhou, Sung Jin Kim, Carrie M. Bartsch, Emily M. Heckman, Fahima Ouchen, Alexander N. Cartwright

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


The potential of using a DNA biopolymer in an electro-optic device is presented. A complex of DNA with the cationic surfactant cetyltrimethylammonium- chloride (CTMA) was used to obtain an organic-soluble DNA material (DNA-CTMA). Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) was added to the DNACTMA to increase the electrical conductivity of the biopolymer. The CW absorbance and time-resolved photoluminescence of the resulting DNA-CTMA and DNA-CTMA-PEDOT:PSS were investigated. Both DNA materials have absorbance peaks at ~260 nm and a broad, Stokes shifted, photoluminescence peak around 470nm. The photoluminescence lifetime of the materials was observed to decrease with increasing UV excitation. Specifically, excitation with a high power ultrafast (~150fs) UV (266nm) laser pulse resulted in a drastic decrease in the photoluminescence lifetime decreases after a few minutes. Moreover, the observed decrease was faster in an air ambient than in a nitrogen ambient. This is most likely due to photo-oxidation that degrades the polymer surface resulting in an increase in the non-radiative recombination. In order to investigate the photoconductivity of these two materials, metal-biopolymer-metal (MBM) ultraviolet photodetectors with interdigitated electrodes were fabricated and characterized. The photoresponsivity of these devices was limited by the transport dynamics within the film. The prospects for the use of these materials in optical devices will be discussed.

Original languageEnglish (US)
Title of host publicationNanobiosystems
Subtitle of host publicationProcessing, Characterization, and Applications IV
StatePublished - 2011
EventNanobiosystems: Processing, Characterization, and Applications IV - San Diego, CA, United States
Duration: Aug 21 2011Aug 22 2011

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherNanobiosystems: Processing, Characterization, and Applications IV
Country/TerritoryUnited States
CitySan Diego, CA


  • biopolymer
  • MBM
  • photodetector

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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