Studies on fluorescein—VIIThe fluorescence of fluorescein as a function of pH

Diehl, Harvey; Markuszewski, R.

doi:10.1016/0039-9140(89)80213-9

Cited by 64 publications

(51 citation statements)

References 5 publications

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“…[73][74][75][76][77][78][79][80] As each of the states possesses a characteristic absorption spectrum, it is possible to follow the changes that occur upon protonation. Figure 2c depicts a few examples.…”

Section: Resultsmentioning

confidence: 99%

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A Molecular Keypad Lock: A Photochemical Device Capable of Authorizing Password Entries

et al. 2006

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This paper describes a new concept in the way information can be protected at the molecular scale. By harnessing the principles of molecular Boolean logic, we have designed a molecular device that mimics the operation of an electronic keypad lock, e.g., a common security circuit used for numerous applications, in which access to an object or data is to be restricted to a limited number of persons. What distinguishes this lock from a simple molecular logic gate is the fact that its output signals are dependent not only on the proper combination of the inputs but also on the correct order by which these inputs are introduced. In other words, one needs to know the exact passwords that open this lock. The different password entries are coded by a combination of two chemical and one optical input signals, which can activate, separately, blue or green fluorescence output channels from pyrene or fluorescein fluorophores. The information in each channel is a single-bit light output signal that can be used to authorize a user, to verify authentication of a product, or to initiate a higher process. This development not only opens the way for a new class of molecular decision-making devices but also adds a new dimension of protection to existing defense technologies, such as cryptography and steganography, previously achieved with molecules.

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Section: Resultsmentioning

confidence: 99%

“…In addition, the first is known to possess higher quantum yield. 73 The corresponding fluorescence spectra for states A-E are shown in Figure 3a.…”

Section: Resultsmentioning

confidence: 99%

A Molecular Keypad Lock: A Photochemical Device Capable of Authorizing Password Entries

et al. 2006

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“…Several groups report FL pK a 's [38,40] to be in the range of 2.1-2.2 (cation), 4.4 (neutral), and 6.7-6.8 (mono-anion). Due to its strong decrease in quantum yield at acid conditions [40,41], we were unable to obtain data for FL below pH 5 (quantum yield of FL is maximum near pH 8). In contrast, R6G and AF488 exhibited approximately uniform fluorescence within the pH range 4-10.…”

Section: Estimation Of Absolute Mobility In Ce Experimentsmentioning

confidence: 98%

Electrophoretic mobility measurements of fluorescent dyes using on‐chip capillary electrophoresis

et al. 2011

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We present an experimental study of the effect of pH, ionic strength, and concentrations of the electroosmotic flow (EOF)-suppressing polymer polyvinylpyrrolidone (PVP) on the electrophoretic mobilities of commonly used fluorescent dyes (fluorescein, Rhodamine 6G, and Alexa Fluor 488). We performed on-chip capillary zone electrophoresis experiments to directly quantify the effective electrophoretic mobility. We use Rhodamine B as a fluorescent neutral marker (to quantify EOF) and CCD detection. We also report relevant acid dissociation constants and analyte diffusivities based on our absolute estimate (as per Nernst-Einstein diffusion). We perform well-controlled experiments in a pH range of 3-11 and ionic strengths ranging from 30 to 90 mM. We account for the influence of ionic strength on the electrophoretic transport of sample analytes through the Onsager and Fuoss theory extended for finite radii ions to obtain the absolute mobility of the fluorophores. Lastly, we briefly explore the effect of PVP on adsorption-desorption dynamics of all three analytes, with particular attention to cationic R6G.

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“…In addition to an increased brightness, the product e l F f , the difference to most cyanines is that cyanines are normally less photo-and chemically stable. Moreover, compared with the positively charged cyanine and rhodamine dyes and the negatively charged fluoresceins, [39] BODIPYs are zwitterionic molecules (Scheme 1), thereby rendering them ideally suitable for a broad range of solvents and environments (e.g., sensor matrices) of different polarity and pH. In addition, most BODIPYs are sufficiently water soluble at concentrations relevant for biochemical or analytical applications.…”

Section: Introductionmentioning

confidence: 99%

Dihydronaphthalene‐Fused Boron–Dipyrromethene (BODIPY) Dyes: Insight into the Electronic and Conformational Tuning Modes of BODIPY Fluorophores

Wang

Descalzo

Shen

et al. 2010

Chemistry A European J

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A new series of boron-dipyrromethene (BDP, BODIPY) dyes with dihydronaphthalene units fused to the beta-pyrrole positions (1a-d, 2) has been synthesised and spectroscopically investigated. All the dyes, except pH-responsive 1d in polar solvents, display intense emission between 550-700 nm. Compounds 1a and 1b with a hydrogen atom and a methyl group in the meso position of the BODIPY core show spectroscopic properties that are similar to those of rhodamine 101, thus rendering them potent alternatives to the positively charged rhodamine dyes as stains and labels for less polar environments or for the dyeing of latex beads. Compound 1d, which carries an electron-donating 4-(dimethylamino)phenyl group in the meso position, shows dual fluorescence in solvents more polar than dibutyl ether and can act as a pH-responsive "light-up" probe for acidic pH. Correlation of the pK(a) data of 1d and several other meso-(4-dimethylanilino)-substituted BODIPY derivatives allowed us to draw conclusions on the influence of steric crowding at the meso position on the acidity of the aniline nitrogen atom. Preparation and investigation of 2, which carries a nitrogen instead of a carbon as the meso-bridgehead atom, suggests that the rules of colour tuning of BODIPYs as established so far have to be reassessed; for all the reported couples of meso-C- and meso-N-substituted BODIPYs, the exchange leads to pronounced redshifts of the spectra and reduced fluorescence quantum yields. For 2, when compared with 1a, the opposite is found: negligible spectral shifts and enhanced fluorescence. Additional X-ray crystallographic analysis of 1a and quantum chemical modelling of the title and related compounds employing density functional theory granted further insight into the features of such sterically crowded chromophores.

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Studies on fluorescein—VIIThe fluorescence of fluorescein as a function of pH

Cited by 64 publications

References 5 publications

A Molecular Keypad Lock: A Photochemical Device Capable of Authorizing Password Entries

A Molecular Keypad Lock: A Photochemical Device Capable of Authorizing Password Entries

Electrophoretic mobility measurements of fluorescent dyes using on‐chip capillary electrophoresis

Dihydronaphthalene‐Fused Boron–Dipyrromethene (BODIPY) Dyes: Insight into the Electronic and Conformational Tuning Modes of BODIPY Fluorophores

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