Brightness and Photostability of Emerging Red and Near‐IR Fluorescent Nanomaterials for Bioimaging

Abstract

Many novel fluorescent nanomaterials exhibit radically different optical properties compared to organic fluorophores that are still the most extensively used class of fluorophores in biology today. Assessing the practical impact of these optical differences for bioimaging experiments is challenging due to a lack of published quantitative benchmarking data. This study therefore directly and quantitatively compares the brightness and photostability of representatives from seven classes of fluorescent materials in spectroscopy and fluorescence microscopy experiments for the first time. These material classes are: organic dyes, semiconductor quantum dots, fluorescent beads, carbon dots, gold nanoclusters, nanodiamonds, and nanorubies. The relative brightness of each material is determined and the minimum material concentrations required to generate sufficient contrast in a fluorescence microscopy image are assessed. The influence of optical filters used for imaging is also discussed and suitable filter combinations are identified. The photostability of all materials is determined under typical imaging conditions and the number of images that can be acquired is inferred. The results are expected to facilitate the transition of novel fluorescent materials from physics and chemistry into biology laboratories.

Vascular thrombus imaging in vivo via near-infrared fluorescent nanodiamond particles bioengineered with the disintegrin bitistatin (Part II)

“…Given the prospect of longer (minutes) scale of imaging procedures in humans, 8 an important consideration in selection of F-NDP has been the stability/durability of the NIR emission. Nanoparticles with similar robustness include quantum dots and nanorubies.…”

“…[5][6][7] Our previous set of in vitro studies, in which we demonstrated the specific association of the F-NDP NVN -Bit with platelets embedded within plasma clot generated by thrombin-activated rat platelet-rich plasma, provided a first-line "proof of feasibility" for our concept. 4 Since transmission of light across biological tissues is subject to interferences (scatter, absorption, diffraction) by organic and inorganic materials of the tissues, 8 we have primarily focused on the near-infrared (NIR) optical window, which significantly facilitates penetration of light through biological tissues. [8][9][10] However, F-NDP with N-V-N color centers (F-NDP NVN ) used in our prior study deliver limited energy in the NIR window, and will most likely fail to penetrate over physiologically relevant distances that could serve medical objectives.…”

“…4 Since transmission of light across biological tissues is subject to interferences (scatter, absorption, diffraction) by organic and inorganic materials of the tissues, 8 we have primarily focused on the near-infrared (NIR) optical window, which significantly facilitates penetration of light through biological tissues. [8][9][10] However, F-NDP with N-V-N color centers (F-NDP NVN ) used in our prior study deliver limited energy in the NIR window, and will most likely fail to penetrate over physiologically relevant distances that could serve medical objectives. Therefore, we expanded our search for an F-NDP strain more suitable to deliver the energy needed to survey vascular lesions such as vascular blood clots.…”

Glass and Process Development for the Next Generation of Optical Fibers: A Review

“…However, the majority of NCs that can be made via alternative synthesis methods cannot be grown in-situ in glass. For example, it is not possible to grow nanodiamond or heterogeneous nanostructures in glass, which limits the ability to engineering optical properties at the nanoscale [56][57][58][59][60]. For NCs that can be grown in-situ, it is still challenging to reach a high level of compositional and nanostructural control over the NCs.…”

Biophotonics: the big picture

“…Other approaches employ unique optical signals that are not normally present in biological systems, such as the use of photonic crystals that provide a way to visualize and sense signals where noise has been heavily suppressed. 9 Again, here adding the time dimension is beneficial, since much of the background photoemission from biological fluorophores occurs very rapidly (∼ns) so that the signal probes with lifetimes > ∼ 30 ns can be acquired with minimal background. Finally, extracting signals from noise using advanced data processing techniques is also proving beneficial in isolating these rare events.…”