Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Sensitivity gains in chemosensing by lasing action in organic polymers


Societal needs for greater security require dramatic improvements in the sensitivity of chemical and biological sensors. To meet this challenge, increasing emphasis in analytical science has been directed towards materials and devices having highly nonlinear characteristics; semiconducting organic polymers (SOPs), with their facile excited state (exciton) transport, are prime examples of amplifying materials1,2,3. SOPs have also been recognized as promising lasing materials4, although the susceptibility of these materials to optical damage has thus far limited applications. Here we report that attenuated lasing in optically pumped SOP thin films displays a sensitivity to vapours of explosives more than 30 times higher than is observed from spontaneous emission. Critical to this achievement was the development of a transducing polymer with high thin-film quantum yield, a high optical damage threshold in ambient atmosphere and a record low lasing threshold. Trace vapours of the explosives 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (DNT) introduce non-radiative deactivation pathways5 that compete with stimulated emission. We demonstrate that the induced cessation of the lasing action, and associated sensitivity enhancement, is most pronounced when films are pumped at intensities near their lasing threshold. The combined gains from amplifying materials and lasing promise to deliver sensors that can detect explosives with unparalleled sensitivity.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Test structures and materials used to demonstrate lasing chemosensory responses.
Figure 2: Stimulated and spontaneous emission of polymer 1 atop a polydimethylsiloxane DFB structure, which is shown in Fig. 1b.
Figure 3: Performance of an optically pumped thin film of polymer 1 on parylene-coated glass before and after exposure to DNT.
Figure 4: Response of a ring-mode laser coated with polymer 1.

Similar content being viewed by others


  1. Zhou, Q. & Swager, T. M. Methodology for enhancing the sensitivity of fluorescent chemosensors: energy migration in conjugated polymers. J. Am. Chem. Soc. 117, 7017–7018 (1995)

    Article  CAS  Google Scholar 

  2. Swager, T. M. The molecular wire approach to sensory signal amplification. Acc. Chem. Res. 31, 201–207 (1998)

    Article  CAS  Google Scholar 

  3. McQuade, D. T., Pullen, A. E. & Swager, T. M. Conjugated polymer-based sensory materials. Chem. Rev. 100, 2537–2574 (2000)

    Article  CAS  Google Scholar 

  4. Tessler, N., Denton, G. J. & Friend, R. H. Lasing from conjugated-polymer microcavities. Nature 382, 695–697 (1996)

    Article  ADS  CAS  Google Scholar 

  5. Yang, J.-S. & Swager, T. M. Porous shape persistent fluorescent polymer films: An approach to TNT sensory materials. J. Am. Chem. Soc. 120, 5321–5322 (1998)

    Article  CAS  Google Scholar 

  6. Cumming, C. J. et al. Using novel fluorescent polymers as sensory materials for above-ground sensing of chemical signature compounds emanating from buried landmines. IEEE Trans. Geosci. Remote Sens. 39, 1119–1128 (2001)

    Article  ADS  Google Scholar 

  7. Rose, A., Lugmair, C. G. & Swager, T. M. Excited-state lifetime modulation in triphenylene-based conjugated polymers. J. Am. Chem. Soc. 123, 11298–11299 (2001)

    Article  CAS  Google Scholar 

  8. Zahn, S. & Swager, T. M. Three-dimensional electronic delocalization in chiral conjugated polymers. Angew. Chem. Int. Edn Engl. 41, 4225–4230 (2002)

    Article  Google Scholar 

  9. Kozlov, V. G., Bulović, V., Burrows, P. E. & Forrest, S. F. Laser action in organic semiconductor waveguide and double heterostructure devices. Nature 389, 362–365 (1997)

    Article  ADS  CAS  Google Scholar 

  10. Bulović, V., Kozlov, V. G., Khalfin, V. B. & Forrest, S. R. Transform-limited, narrow-linewidth lasing action in organic semiconductor microcavities. Science 279, 553–555 (1998)

    Article  ADS  Google Scholar 

  11. Scherf, U., Riechel, S., Lemmer, U. & Mahrt, R. F. Conjugated polymers: lasing and stimulated emission. Curr. Opin. Solid State Mater. Sci. 5, 143–154 (2001)

    Article  ADS  CAS  Google Scholar 

  12. Halls, J. J. M., Pichler, K., Friend, R. H., Moratti, S. C. & Holmes, A. B. Exciton diffusion and dissociation in a poly(p-phenylenevinylene)/C60 heterojunction photovoltaic cell. Appl. Phys. Lett. 68, 3120–3122 (1996)

    Article  ADS  CAS  Google Scholar 

  13. Hamer, P. J. et al. Optical studies of chemical doping achieved by ion implantation in poly(p-phenylene vinylene). Phil. Mag. B 73, 367–382 (1996)

    Article  ADS  CAS  Google Scholar 

  14. Levitsky, I. A., Kim, J. & Swager, T. M. Energy migration in a poly(phenylene ethynylene): determination of interpolymer transport in anisotropic Langmuir-Blodgett films. J. Am. Chem. Soc. 121, 1466–1472 (1999)

    Article  CAS  Google Scholar 

  15. Kogelnik, H. & Shank, C. V. Stimulated emission in a periodic structure. Appl. Phys. Lett. 18, 152–154 (1971)

    Article  ADS  CAS  Google Scholar 

  16. Heliotis, G. et al. Emission characteristics and performance comparison of polyfluorene lasers with one- and two-dimensional distributed feedback. Adv. Funct. Mater. 14, 91–97 (2004)

    Article  CAS  Google Scholar 

  17. Berggren, M., Dodabalapur, A., Slusher, R. E. & Bao, Z. Light amplification in organic thin films using cascade energy transfer. Nature 389, 466–469 (1997)

    Article  ADS  CAS  Google Scholar 

  18. Yang, Y.-S. & Swager, T. M. Fluorescent porous polymer films as TNT chemosensors: electronic and structural effects. J. Am. Chem. Soc. 120, 11864–11873 (1998)

    Article  CAS  Google Scholar 

Download references


This work was supported by NASA, the Institute for Soldier Nanotechnologies, and the NSF through the Center for Materials Science and Engineering. A.R. acknowledges V. Sundar and H. Eisler for discussions and J. Ho for providing the DFB structures used in this work.

Author information

Authors and Affiliations


Corresponding authors

Correspondence to Timothy M. Swager or Vladimir Bulović.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Notes

This file contains the Supplementary Methods, Supplementary Data (including Supplementary Figures S1-S4) and additional references. The file details the synthesis of Polymer 1 (part A), theoretical model of TNT quenching of lasing action (part B), data on photostabiltiy of Polymer 1 laser devices (part C) and high-resolution spectra of multimode lasing of Polymer 1 in asymmetric waveguides (part D). (PDF 160 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Rose, A., Zhu, Z., Madigan, C. et al. Sensitivity gains in chemosensing by lasing action in organic polymers. Nature 434, 876–879 (2005).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing