&lt;title&gt;Bacteriorhodopsin-based photochromic pigments for optical security applications&lt;/title&gt;

Hampp, Norbert; Fischer, Thorsten; Neebe, Martin

doi:10.1117/12.462703

Cited by 8 publications

(6 citation statements)

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“…The estimated information density is far more than traditional platter architectures, but cost, processing, and reusability issues have precluded commercialization. Bacteriorhodopsin has long been considered a good candidate material for device applications due to its unique photochemical properties, including high sensitivity, high cyclicity, and good thermal stability. − BR-based holography has been a subject of active interest for well over a decade, − with the promises of ultrahigh storage density (5000 lines/mm), full write−read−erase capabilities, and excellent potential for fine-tuning performance through genetic modification. ,− ,− The earliest attempts utilized the wild-type protein to generate real-time holographic gratings between the bR resting state and the M-state, with the lifetime of the latter often enhanced by the addition of various amines. ,, The genetically engineered BR variant D96N has attracted special attention due to its prolonged M-state and has even been utilized in a commercial holographic interferometer designed for nondestructive testing . The prolonged M-state lifetime (up to several minutes) gives the resulting holographic material high sensitivity and acceptable diffraction efficiency (as high as 7% in a 5 OD film 19 ).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Blue and Green Absorbing Proteorhodopsins as Holographic Materials

Tetley²,

Marcy³

et al. 2008

J. Phys. Chem. B

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Transient holographic diffraction is observed for the green (GPR) and blue (BPR) absorbing proteorhodopsins (BAC31A8 and HOT75M1, respectively), as well as the GPR E108Q and BPR E110Q variants. In contrast to bacteriorhodopsin, where the metastable bR-M pair is responsible for generating diffraction, the pR and red-shifted N-like states fulfill that role in both the green and blue wild-type proteorhodopsins. The GPR E108Q and BPR E110Q variants, however, behave more similarly to their bacteriorhodopsin analogue, D96N, with diffraction arising from the PR M-state (strongly enhanced in both GPR E108Q and BPR E110Q). Of the four proteins evaluated, wild type (WT) GPR and GPR E108Q produce the highest diffraction efficiencies, etamax, at approximately 1% for a 1.7 OD sample. GPR E108Q, however, requires 1-2 orders of magnitude less laser intensity to generate eta equivalent to WT GPR and BR D96N under similar conditions (as compared to literature values). WT BPR requires lower actinic powers than GPR but diffracts only about 30% as well. BPR E110Q performs the most poorly of the four, with etamax < 0.05% for a 1.4 OD film. The Kramers-Kronig transformation and Koglenik's coupled wave theory were used to predict the dispersion spectra and diffraction efficiency for the long M-state variants. To a first approximation, the gratings formed by all samples decay upon discontinuing the 520 nm actinic beams with a time constant characteristic of the appropriate intermediate: the N-like state for WT GPR and BPR and the M-state for GPR 108Q and BPR E110Q.

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Section: Introductionmentioning

confidence: 99%

Evaluation of Blue and Green Absorbing Proteorhodopsins as Holographic Materials

Tetley²,

Marcy³

et al. 2008

J. Phys. Chem. B

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“…The ability of OR to photorecycle and to slowly decay to equilibrium shows that this material has characteristics similar to those observed in the D96N mutant bR. 7 The observation of the same properties in thin films suggests the possibility to employ this new biomaterial in biomolecular electronic applications, as confirmed by its photovoltaic response.…”

Section: Discussionmentioning

confidence: 63%

“…Bacteriorhodopsin (bR) and other light‐sensitive proteins, including visual pigments (rhodopsin) from bovine,1–4 photosynthetic reaction centers5 are of interest for use in biotechnology and molecular electronic applications 6–10. The unique combination of photochromic, photoelectric and electrooptical properties of these proteins is of great fundamental and applied interest.…”

Section: Introductionmentioning

confidence: 99%

“…Bacteriorhodopsin (bR) and other light-sensitive proteins, including visual pigments (rhodopsin) from bovine, [1][2][3][4] photosynthetic reaction centers 5 are of interest for use in biotechnology and molecular electronic applications. [6][7][8][9][10] The unique combination of photochromic, photoelectric and electrooptical properties of these proteins is of great fundamental and applied interest. bR is a promising candidate for information processing because of its astonishing stability against chemical, thermal and photochemical degradation as well as its efficient photochemistry and excellent reversibility.…”

Section: Introductionmentioning

confidence: 99%

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Photoreversibility and photostability in films of octopus rhodopsin isolated from octopus photoreceptor membranes

Paternolli¹,

Neebe²,

Stura³

et al. 2008

J Biomedical Materials Res

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In this work, a new biomaterial resulting from the isolation of octopus rhodopsin (OR) starting from octopus photoreceptor membranes is presented. Mass spectroscopic characterization was employed in order to verify the presence of rhodopsin in the extract. Photoreversibility and photochromic properties were investigated using spectrophotometric measurements and pulsed light. Thin films of OR were realized using the gel-matrix entrapment method in polyvinyl alcohol solution. The results indicate that the photoreversibility and the photostability of the OR in gel-matrices are maintained. Several measurements were performed to test the stability of the resulting biomaterial in time and at room temperature. Preliminary tests demonstrate that the photoreversibility and the photostability are still found after few days from the biomaterial preparation and after the exposure for several hours at room temperature.

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“…The PEGylation yields nanoscaled protected PMs without enhancing the scattering as only minor size changes occur and the refractive index of the PEG–water hull is very close to the value of unmodified PM. This new alternative encapsulation of PM widens the possible applications of BR, such as a photochromic pigment in security inks. , Further this result may be useful for membrane stabilization in general.…”

Section: Discussionmentioning

confidence: 89%

PEGylation of Membrane Proteins Like Bacteriorhodopsin as a Tool to Increase Their Stability toward Ethanol

2012

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Protection of biological compounds, for example, enzymes, viruses, or even whole cells, against degradation is very important for many applications. Embedding of such compounds into polymer matrices is a straightforward common method. However, in biotechnology and medicine there is a great interest to prepare micro- and nanosized shells around the biocomponents in order to protect them and having only a minor increase in size. The PEGylation of biological macromolecules has gained attention because degradation by proteolytic enzymes is significantly retarded and, in turn, their bioavailability is enhanced. We found that PEGylation is also a powerful tool to protect biomaterials from degradation by small organic solvent molecules, in particular, ethanol. Methoxy-polyethylene glycol (MPEG) modified BR survives exposure to significant concentrations of ethanol, up to 30%, and preserves its photochromism, whereas unmodified PM is instantaneously denatured at such concentrations. This is useful for potential technical applications of BR but is of relevance for many other applications where biomaterials and, in particular, biomembranes may be exposed to solvents.

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<title>Bacteriorhodopsin-based photochromic pigments for optical security applications</title>

Cited by 8 publications

References 0 publications

Evaluation of Blue and Green Absorbing Proteorhodopsins as Holographic Materials

Evaluation of Blue and Green Absorbing Proteorhodopsins as Holographic Materials

Photoreversibility and photostability in films of octopus rhodopsin isolated from octopus photoreceptor membranes

PEGylation of Membrane Proteins Like Bacteriorhodopsin as a Tool to Increase Their Stability toward Ethanol

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