| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1494051 | Optical Materials | 2014 | 9 Pages |
•Two-photon polymerized 3D microstructures were functionalized with gold nanoparticles.•Localized fluorescent enhancement was achieved by the microstructures.•Fluorescent enhancement is via the classic standing wave mechanism.
Fluorescence enhancement achieved by functionalized microstructures made by two-photon polymerization (TPP) is reported for the first time. Microstructures of various shapes made of SU-8 photoresist were prepared and coated with gold nanoparticles (NP) of 80 nm. Localized fluorescence enhancement was demonstrated by microstructures equipped with tips of sub-micron dimensions. The enhancement was realized by positioning the NP-coated structures over fluorescent protein layers. Two fluorophores with their absorption in the red and in the green region of the VIS spectrum were used. Laser scanning confocal microscopy was used to quantify the enhancement. The enhancement factor was as high as 6 in areas of several square-micrometers and more than 3 in the case of local enhancement, comparable with literature values for similar nanoparticles. The structured pattern of the observed fluorescence intensity indicates a classic enhancement mechanism realized by standing waves over reflecting surfaces. With further development mobile microtools made by TPP and functionalized by metal NPs can be actuated by optical tweezers and position to any fluorescent micro-object, such as single cells to realize localized, targeted fluorescence enhancement.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (81 K)Download as PowerPoint slide
