Novel sub-100 nm surface chemical modification by optical near-field induced photocatalytic reaction

Abstract

The surface modification is indispensable to facilitate new functional applications of micro/nanofluidics devices. Among many modification techniques developed so far, the photo-induced chemical modification is the most versatile method in terms of robustness, process simplicity, and feasibility of chemical functionality. In particular, the method is useful for closed spaces, such as post-bonded devices. However, the limitation by optical diffraction limit is still a challenging issue in scaling down the pattern sizes to nanoscale. Here, we demonstrated a novel surface modification on sub-100 nm scale utilizing the novel optical near-field (ONF) generated on nanostructures of photocatalyst (TiO2). The minimum pattern size of 40 nm, which was much smaller than diffraction limit, was achieved using a visible light source (488 nm) and a conventional irradiation setup. The controllability of pattern size by light intensity, the feasibility of functionality, and the non-contact working mode have impacts on surface patterning of post-bonded micro/nanofluidics devices. It is also worthy to note that our results verified for the first time the ONF on nanostructures of non-metal materials and its ability to manipulate the chemical reaction on nanoscale.

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References

  1. Bunimovich Y, Ge G, Ries R, Beverly K, Hood L, Heath J (2004) Electrochemically programmed, spatially selective biofunctionalization of silicon wires. Langmuir 20:10630–10638

    Article  Google Scholar 

  2. Delamarche E, Juncker D, Schmid H (2005) Microfluidics for processing surfaces and miniaturizing biological assays. Adv Mater 17:2911–2933

    Article  Google Scholar 

  3. Ganesan R, Kratza K, Lendlein A (2010) Multicomponent protein patterning of material surfaces. J Mater Chem 20:7322–7331

    Article  Google Scholar 

  4. Hibara A, Nonaka M, Hisamoto H, Uchiyama K, Kikutani Y, Tokeshi M, Kitamori T (2002) Stabilization of liquid interface and control of two-phase confluence and separation in glass microchips by utilizing octadecylsilane modification of microchannels. Anal Chem 74:1724–1728

    Article  Google Scholar 

  5. Hibara A, Takumi S, Kim H-B, Tokeshi M, Ooi T, Nakao M, Kitamori T (2003) Liquid properties investigation by time-resolved fluorescence measurements. Anal Chem 36:605–612

    Google Scholar 

  6. Huo F, Zheng Z, Zheng G, Giam LR, Zhang H, Mirkin CA (2008) Polymer pen lithography. Science 321:1658–1660

    Article  Google Scholar 

  7. Jane A, Dronov R, Hodges A, Voelcker NH (2009) Porous silicon biosensors on the advance. Trends Biotechnol 27:230–240

    Article  Google Scholar 

  8. Juodkazis S, Yamaguchi A, Ishii H, Matsuo S, Takagi H, Misawa H (2001) Photo-electrochemical deposition of platinum on TiO2 with resolution of twenty nanometers using a mask elaborated with electron-beam lithography. Jpn J Appl Phys 40:4246–4251

    Article  Google Scholar 

  9. Kawazoe T, Ohtsu M, Inao Y, Kuroda R (2007) Exposure dependence of the developed depth in nonadiabatic photolithography using visible optical near fields. J Nanophoton 1:011595

    Article  Google Scholar 

  10. Kawazoe T, Fujiwara H, Kobayashi K, Ohtsu M (2009) Visible light emission from dye molecular grains via infrared excitation based on the nonadiabatic transition induced by the optical near field. J Sel Top Quantum Electron 15:1380–1386

    Article  Google Scholar 

  11. König T, Sekhara YN, Santer S (2012) Surface plasmon nanolithography: impact of dynamically varying near-field boundary conditions at the air–polymer interface. J Mater Chem 22:5945–5950

    Article  Google Scholar 

  12. Le THH, Mawatari K, Pihosh Y, Kawazoe T, Yatsui T, Ohtsu M, Tosa M, Kitamori T (2011) Optical near-field induced visible response photoelectrochemical water splitting on nanorod TiO2 Appl. Phys Lett 99:213105–213108

    Google Scholar 

  13. Le THH, Mawatari K, Hasumoto N, Pihosh Y, Kitamura K, Kawazoe T, Yatsui T, Naruse M, Ohtsu M, Kitamori T (2012) Optical near-field induced chemical partial hydrophobic/hydrophilic modification with sub-diffraction limit resolution. In: Proceedings of the 16th μTAS conference, pp 222–224

  14. Luo X, Ishihara T (2004) Subwavelength photolithography based on surface-plasmon polariton resonance. Opt Express 12:3055

    Article  Google Scholar 

  15. Mawatari K, Kubota S, Xu Y, Priest C, Sedev R, Ralston J, Kitamori T (2013) Femtoliter droplet handling in nanofluidic channels: a Laplace nanovalve. Anal Chem 84:10812–10816

    Article  Google Scholar 

  16. Menard E (2007) Micro- and nanopatterning techniques for organic electronic and optoelectronic systems. Chem Rev 107:1117–1160

    Article  Google Scholar 

  17. Mendes PM, Yeung CL, Preece JA (2007) Bio-nanopatterning of surfaces. Nanoscale Res Lett 2:373–384

    Article  Google Scholar 

  18. Park I, Li Z, Pisano AP, Williams RS (2007) Selective surface functionalization of silicon nanowires via nanoscale Joule heating. Nano Lett 7:3106–3111

    Article  Google Scholar 

  19. Priest C (2010) Surface patterning of bonded microfluidic channels. Biomicrofluidic 4(3):32206–32219

    MathSciNet  Article  Google Scholar 

  20. Pu Q, Yun JS, Temkin H, Liu SR (2004) Ion-enrichment and ion-depletion effect of nanochannel structures. Nano Lett 4:1099–1103

    Article  Google Scholar 

  21. Qi M, Lidorikis E, Rakich PK, Johnson SG, Joannopoulos JD, Ippen EP, Smith HI (2004) A three-dimensional optical photonic crystal with designed point defects. Nature 429:538–542

    Article  Google Scholar 

  22. Tseng AA, Notargiacomo A, Chen TP (2005) Nanofabrication by scanning probe microscope lithography: a review. J Vac Sci Technol B 23:877–894

    Article  Google Scholar 

  23. Tsukahara T, Hibara A, Ikeda K, Kitamori T (2007) NMR study of water molecules confined in extended nanospaces. Angew Chem Int Ed 46:1180–1183

    Article  Google Scholar 

  24. Ueno K, Juodkazis S, Shibuya T, Yokota Y, Mizeikis V, Sasaki K, Misawa H (2008) Nanoparticle plasmon-assisted two-photon polymerization induced by incoherent excitation source. J Am Chem Soc 130:6928–6929

    Article  Google Scholar 

  25. Valev VK, De Clercq B, Biris CG, Zheng X, Vandendriessche S, Hojeij M, Denkova D, Jeyaram Y, Panoiu NC, Ekinci Y, Silhanek AV, Volskiy V, Vandenbosch GAE, Ameloot M, Moshchalkov VV, Verbiest T (2012) Distributing the optical near-field for efficient field-enhancements in nanostructures. Adv Opt Mater 24:208–215

    Google Scholar 

  26. West J, Becher M, Tombrink S, Manz A (2008) Micro total analysis systems: latest achievements. Anal Chem 80:4403–4419

    Article  Google Scholar 

  27. Wouters D, Schubert US (2004) Nanolithography and nanochemistry: probe-related patterning techniques and chemical modification for nanometer-sized devices. Angew Chem Int Ed 43:2480–2495

    Article  Google Scholar 

  28. Xia Y, Whitesides GM (1998) Soft lithography. Angew Chem Int Ed 37:550–575

    Article  Google Scholar 

  29. Yatsui T, Hirata K, Nomura W, Tabata Y, Ohtsu M (2008) Realization of an ultra-flat silica surface with angstrom-scale average roughness using nonadiabatic optical near-field etching. Appl Phys B 93:55–57

    Article  Google Scholar 

  30. Yonemitsu H, Kawazoe T, Kobayashi K, Ohtsu M (2005) Nonadiabatic photochemical reaction and application to photolithography. J Lumin 122:230–233

    Google Scholar 

  31. Yukutake S, Kawazoe T, Yatsui T, Hirata K, Nomura W, Kitamura K, Ohtsu M (2010) Selective photocurrent generation in the transparent wavelength range of a semiconductor photovoltaic device using a phonon-assisted optical near-field process. Appl Phys B 99:415–422

    Article  Google Scholar 

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Acknowledgments

This work was partially supported by JSPS Core-to-Core Program and the Grant-in-Aid for Specially Promoted Research. We also would like to thank to the Research Hub for Nano Characterization Center at the University of Tokyo for SEM measurement.

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Correspondence to Takehiko Kitamori.

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Le, T.H.H., Mawatari, K., Pihosh, Y. et al. Novel sub-100 nm surface chemical modification by optical near-field induced photocatalytic reaction. Microfluid Nanofluid 17, 751–758 (2014). https://doi.org/10.1007/s10404-014-1361-7

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Keywords

  • Surface modification on nanoscale
  • Modification of bonded chip
  • Optical near-field
  • Photocatalytic chemical modification