Vesicular perylene dye nanocapsules as supramolecular fluorescent pH sensor systems

Abstract

Water-soluble, self-assembled nanocapsules composed of a functional bilayer membrane and enclosed guest molecules can provide smart (that is, condition responsive) sensors for a variety of purposes. Owing to their outstanding optical and redox properties, perylene bisimide chromophores are interesting building blocks for a functional bilayer membrane in a water environment. Here, we report water-soluble perylene bisimide vesicles loaded with bispyrene-based energy donors in their aqueous interior. These loaded vesicles are stabilized by in situ photopolymerization to give nanocapsules that are stable over the entire aqueous pH range. On the basis of pH-tunable spectral overlap of donors and acceptors, the donor-loaded polymerized vesicles display pH-dependent fluorescence resonance energy transfer from the encapsulated donors to the bilayer dye membrane, providing ultrasensitive pH information on their aqueous environment with fluorescence colour changes covering the whole visible light range. At pH 9.0, quite exceptional white fluorescence could be observed for such water-soluble donor-loaded perylene vesicles.

Absorption and Emission Spectra of a Flexible Dye in Solution: A Computational Time-Dependent Approach

“…The potential energies governing rotations around dihedrals δ 1 -δ 4 are described by sums of cosines, namely (3) where is the force constant, δ μ the dihedral, and the multiplicity and a phase factor for the j th cosine. N μ is the number of cosine functions employed for dihedral μ.…”

“…Organic dyes 1 have recently attracted a growing attention, thanks to their wide range of applications, that covers different fields in both materials [2][3][4][5][6][7][8][9][10][11] and life sciences. [12][13][14][15] In particular, the high selectivity and specificity of some fluorescent molecules in detecting particular molecular targets and/or in modulating the responses to different external stimuli are often exploited to investigate the structural and dynamic properties of a wide variety of complex systems like, e.g., polymeric materials, DNA structures, protein conformations or lipid aggregates.…”

“…2. The equilibrium coordinates r 0 , θ 0 , ϕ 0 (reported in Å and deg, respectively) and the force constants k b , k b , k t , (in kJ/mol Å −2 , kJ/mol rad −2 and kJ/mol) have been defined in equations (1)(2)(3). The complete parameter set can be found in the supporting informations.…”

Environment‐Adaptive Coassembly/Self‐Sorting and Stimulus‐Responsiveness Transfer Based on Cholesterol Building Blocks

“…Apart from enhancing interactions, another common design protocol is to increase structural similarity of different components 20, 21, 22. Structural similarity reduces the discrimination and exclusionary possibility during the aggregation process, resulting in the interdigitation arrangement.…”

Flow Injection Small-volume Fiber-optic pH Sensor Based on Evanescent Wave Excitation and Fluorescence Determination

“…Though several other fluorescence measurement methods, including lifetime measurement [11,27], ratiometric dual-wavelength measurement [28][29][30], and photoinduced electron transfer (PET) measurement [31] have been developed, fluorescence intensity measurement [32][33][34] is still one of the most widely employed analytical techniques. This is mainly because the intensity measurement has no demand on sophisticated instrumentations, has no lost of spectral information, and generally does not need fluorophore receptor.…”