Fluorescence Spectroscopy: Applications in Chemical Biology

Abstract

Fluorescence spectroscopy in all of its variations can be considered among the most powerful types of analysis available to chemical biology. However, to be useful almost all applications are dependent on optimal labeling of biomolecules with a fluorophore and on the appropriate choice of analytical technique. In this article, we examine the applications and contributions of fluorescent spectroscopy to chemical biology in three inter‐related sections. We first examine the properties of the common fluorophores available from many disparate structural and functional classes, which includes a discussion of their individual benefits and liabilities in the context of their application. The available conjugation chemistries used to attach fluorophores to myriad biomolecules are next reviewed. As each class of biomolecule differs in both structure and function, the focus here is on strategies for the specific labeling of different functional groups. Last, some major types of fluorescent spectroscopy and the associated biologic questions and analysis that can be addressed with them are covered briefly.

Peptides for Specific Intracellular Delivery and Targeting of Nanoparticles: Implications for Developing nanoparticle-mediated Drug Delivery

“…For example, if a particular sequence or functional group is required for subsequent peptidyl activity in the conjugate, such as the presence of a primary amine, then chemistries that specifically target and modify this group would not be favored to yield functional composites. A number of related reviews and sources are available that discuss some of these pertinent issues and chemistries [22][23][24]. There are currently four general strategies commonly applied for attaching peptides to NP materials (FiguRes 1 & 2) and each is characterized by its own inherent set of benefits and liabilities [22].…”

“…The development of novel and elegant bioconjugation chemistries will be the key driver in mediating the advancements in the subsequent three areas. As described earlier, the attachment of peptides onto the NP surface in a homogeneous manner with control over their orientation, distance and valence is critical for optimal function [19,[22][23][24]. The same holds true for the attachment of any biological, chemical or drug moiety and, as mentioned earlier, there is a growing interest within the field of NMDD to create thera nostic NP structures that can effectively combine multiple functions (e.g., cell targeting, imaging and drug delivery).…”

Multilayer Microcapsules for FRET Analysis and Two‐Photon‐Activated Photodynamic Therapy

“…[1,2] TheF RET efficiency strongly depends on several factors,such as the extent of the spectral overlap,the quantum yield of the fluorophores,and, most importantly,t he distance between donor and acceptor (D/A, proximity of 1-10 nm). In this process,a ne xcited-state donor fluorophore transfers energy to ap roximal ground-state acceptor fluorophore through nonradiative dipole-dipole coupling.…”

“…In this process,a ne xcited-state donor fluorophore transfers energy to ap roximal ground-state acceptor fluorophore through nonradiative dipole-dipole coupling. [1,[4][5][6] Beyond that, in recent years,t he application of FRET has been extended to cancer research, for example,i np hotodynamic therapy (PDT). [3,4] In general, the FRET rate is inversely proportional to the sixth power of this distance, making FRET extremely sensitive to small changes in the distance between donor and acceptor.T herefore,F RET has been used to measure the distance between D/A molecules and to detect molecular interactions in an umber of systems, and has applications in biology and chemistry.…”

Building‐Block Approach for the Straightforward Incorporation of a New FRET (Fluorescence‐Resonance‐Energy Transfer) System into Synthetic DNA

“…-Fluorescently labelled nucleic acids are particularly important tools in molecular biology, diagnostics, and structural studies [1] [2]. In this context, DNA with incorporated dyes representing fluorescence-resonance-energy transfer (FRET) systems have proven to be important tools for the elucidation of distance-dependent interactions on the molecular level and in real time mode.…”