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Interference lithographic nanopatterning of plant and bacterial light-harvesting complexes on gold substrates.

Patole S, Vasilev C, El-Zubir O, Wang L, Johnson MP, Cadby AJ, Leggett GJ, Hunter CN - Interface Focus (2015)

Bottom Line: A Lloyd's mirror dual-beam interferometer was used to expose self-assembled monolayers of amine-terminated alkylthiolates on gold to laser irradiation.These amine patterns could be derivatized with nitrilotriacetic acid (NTA), so that polyhistidine-tagged bacteriochlorophyll-protein complexes from phototrophic bacteria could be attached with a defined surface orientation.By varying parameters such as the angle between the interfering beams and the laser irradiation dose, it was possible to vary the period and widths of NTA and amine-functionalized lines on the surfaces; periods varied from 1200 to 240 nm and linewidths as small as 60 nm (λ/4) were achieved.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry , University of Sheffield , Brook Hill, Sheffield S3 7HF , UK ; Department of Molecular Biology and Biotechnology , University of Sheffield , Western Bank, Sheffield S10 2TN , UK.

ABSTRACT
We describe a facile approach for nanopatterning of photosynthetic light-harvesting complexes over macroscopic areas, and use optical spectroscopy to demonstrate retention of native properties by both site-specifically and non-specifically attached photosynthetic membrane proteins. A Lloyd's mirror dual-beam interferometer was used to expose self-assembled monolayers of amine-terminated alkylthiolates on gold to laser irradiation. Following exposure, photo-oxidized adsorbates were replaced by oligo(ethylene glycol) terminated thiols, and the remaining intact amine-functionalized regions were used for attachment of the major light-harvesting chlorophyll-protein complex from plants, LHCII. These amine patterns could be derivatized with nitrilotriacetic acid (NTA), so that polyhistidine-tagged bacteriochlorophyll-protein complexes from phototrophic bacteria could be attached with a defined surface orientation. By varying parameters such as the angle between the interfering beams and the laser irradiation dose, it was possible to vary the period and widths of NTA and amine-functionalized lines on the surfaces; periods varied from 1200 to 240 nm and linewidths as small as 60 nm (λ/4) were achieved. This level of control over the surface chemistry was reflected in the surface topology of the protein nanostructures imaged by atomic force microscopy; fluorescence imaging and spectral measurements demonstrated that the surface-attached proteins had retained their native functionality.

No MeSH data available.


Related in: MedlinePlus

Spectroscopic characterization of RC-LH1-PufX complexes immobilized on Ni2+–NTA lines patterned by IL on gold substrates. (a) False colour fluorescence image. (b) The fluorescence emission spectrum recorded on immobilized complexes.
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RSFS20150005F5: Spectroscopic characterization of RC-LH1-PufX complexes immobilized on Ni2+–NTA lines patterned by IL on gold substrates. (a) False colour fluorescence image. (b) The fluorescence emission spectrum recorded on immobilized complexes.

Mentions: The fluorescence emitted from the bacteriochlorophyll or chlorophyll pigments of photosynthetic complexes is a useful indicator of their structural integrity and function. In the case of RC-LH1-PufX complexes, a closely packed ring of 28 bacteriochlorophylls, attached to LH1 polypeptides, forms a belt round each RC, the site of charge separation [50]. Monomeric bacteriochlorophylls in solvent emit fluorescence at approximately 780 nm, whereas their assembly into ring-like structures red-shifts their emission by over 100 nm [52]. The presence of red-shifted fluorescence is therefore a useful measure of retained structure and function following immobilization onto IL-patterned Ni2+–NTA. To investigate the possible effects of immobilizing RC-LH1-PufX complexes on patterned surfaces, we recorded the florescence emission of Ni2+–NTA patterns using a home-built inverted epifluorescence microscope. Patterned core complexes were excited at 470 nm with a collimated LED light source, and the resulting fluorescence was collected through a spectrometer onto an EMCCD camera. The image in figure 5a shows the lines of fluorescent RC-LH1-PufX complexes; a region of interest on the pattern was defined by closing the slits of the spectrometer and, using a suitable grating and centre wavelength, the fluorescence emission spectrum was measured (figure 5b). The 885 nm fluorescence emission maximum shows that the RC-LH1-PufX complexes have retained their native properties following surface immobilization.Figure 5.


Interference lithographic nanopatterning of plant and bacterial light-harvesting complexes on gold substrates.

Patole S, Vasilev C, El-Zubir O, Wang L, Johnson MP, Cadby AJ, Leggett GJ, Hunter CN - Interface Focus (2015)

Spectroscopic characterization of RC-LH1-PufX complexes immobilized on Ni2+–NTA lines patterned by IL on gold substrates. (a) False colour fluorescence image. (b) The fluorescence emission spectrum recorded on immobilized complexes.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4590419&req=5

RSFS20150005F5: Spectroscopic characterization of RC-LH1-PufX complexes immobilized on Ni2+–NTA lines patterned by IL on gold substrates. (a) False colour fluorescence image. (b) The fluorescence emission spectrum recorded on immobilized complexes.
Mentions: The fluorescence emitted from the bacteriochlorophyll or chlorophyll pigments of photosynthetic complexes is a useful indicator of their structural integrity and function. In the case of RC-LH1-PufX complexes, a closely packed ring of 28 bacteriochlorophylls, attached to LH1 polypeptides, forms a belt round each RC, the site of charge separation [50]. Monomeric bacteriochlorophylls in solvent emit fluorescence at approximately 780 nm, whereas their assembly into ring-like structures red-shifts their emission by over 100 nm [52]. The presence of red-shifted fluorescence is therefore a useful measure of retained structure and function following immobilization onto IL-patterned Ni2+–NTA. To investigate the possible effects of immobilizing RC-LH1-PufX complexes on patterned surfaces, we recorded the florescence emission of Ni2+–NTA patterns using a home-built inverted epifluorescence microscope. Patterned core complexes were excited at 470 nm with a collimated LED light source, and the resulting fluorescence was collected through a spectrometer onto an EMCCD camera. The image in figure 5a shows the lines of fluorescent RC-LH1-PufX complexes; a region of interest on the pattern was defined by closing the slits of the spectrometer and, using a suitable grating and centre wavelength, the fluorescence emission spectrum was measured (figure 5b). The 885 nm fluorescence emission maximum shows that the RC-LH1-PufX complexes have retained their native properties following surface immobilization.Figure 5.

Bottom Line: A Lloyd's mirror dual-beam interferometer was used to expose self-assembled monolayers of amine-terminated alkylthiolates on gold to laser irradiation.These amine patterns could be derivatized with nitrilotriacetic acid (NTA), so that polyhistidine-tagged bacteriochlorophyll-protein complexes from phototrophic bacteria could be attached with a defined surface orientation.By varying parameters such as the angle between the interfering beams and the laser irradiation dose, it was possible to vary the period and widths of NTA and amine-functionalized lines on the surfaces; periods varied from 1200 to 240 nm and linewidths as small as 60 nm (λ/4) were achieved.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry , University of Sheffield , Brook Hill, Sheffield S3 7HF , UK ; Department of Molecular Biology and Biotechnology , University of Sheffield , Western Bank, Sheffield S10 2TN , UK.

ABSTRACT
We describe a facile approach for nanopatterning of photosynthetic light-harvesting complexes over macroscopic areas, and use optical spectroscopy to demonstrate retention of native properties by both site-specifically and non-specifically attached photosynthetic membrane proteins. A Lloyd's mirror dual-beam interferometer was used to expose self-assembled monolayers of amine-terminated alkylthiolates on gold to laser irradiation. Following exposure, photo-oxidized adsorbates were replaced by oligo(ethylene glycol) terminated thiols, and the remaining intact amine-functionalized regions were used for attachment of the major light-harvesting chlorophyll-protein complex from plants, LHCII. These amine patterns could be derivatized with nitrilotriacetic acid (NTA), so that polyhistidine-tagged bacteriochlorophyll-protein complexes from phototrophic bacteria could be attached with a defined surface orientation. By varying parameters such as the angle between the interfering beams and the laser irradiation dose, it was possible to vary the period and widths of NTA and amine-functionalized lines on the surfaces; periods varied from 1200 to 240 nm and linewidths as small as 60 nm (λ/4) were achieved. This level of control over the surface chemistry was reflected in the surface topology of the protein nanostructures imaged by atomic force microscopy; fluorescence imaging and spectral measurements demonstrated that the surface-attached proteins had retained their native functionality.

No MeSH data available.


Related in: MedlinePlus