Quantum Dot-Based Hybrid Nanostructures and Energy Transfer on the Nanoscale for Single- and Multi-Photon Imaging and Cancer Diagnostics

1st International Symposium 'Physics, Engineering and Technologies for Bio-Medicine'

医药卫生;物理学;工业技术

Nabiev, Igor^1,2

Laboratoire de Recherche en Nanosciences, LRN - EA4682, Université de Reims Champagne-Ardenne, Reims, France^1

Laboratory of Nano-Bioengineering, National Research Nuclear University, MEPhI (Moscow Engineering Physics Institute), Moscow, Russia^2

关键词: Absorption cross sections;    Cancer diagnostics;    Hybrid nanostructures;    Nanoparticle surface;    Secondary antibodies;    Single-domain antibodies;    Specific recognition;    Tissue autofluorescence;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/784/1/012041/pdf
DOI  :  10.1088/1742-6596/784/1/012041

来源: IOP

【 摘 要 】

An ideal single-photon (1P) or multiphoton fluorescent nanoprobe should combine a nanocrystal with the largest possible 1P or two-photon (2P) absorption cross section and the smallest possible highly specific recognition molecules conjugated with the nanoparticle in an oriented manner. However, the conditions used for conjugation of typical recognition molecules (conventional antibodies, Abs) with nanoparticles often provoke their unfolding and/or yield nanoprobes with irregular orientation of Abs on the nanoparticle surface. Conjugation of smaller Ab fragments, such as single-domain antibodies (sdAbs), with quantum dots (QDs) in an oriented manner can be considered as an attractive approach to engineering of ultrasmall diagnostic nanoprobes. QDs conjugated to 13-kDa sdAbs derived from camelid IgG or streptavidin have been used as efficient 1P or 2P excitation probes for imaging of cancer markers. The 2P absorption cross sections (TPACSs) for some conjugates are higher than 49,000 GM (Goeppert-Mayer units), which is close to the theoretical value calculated for CdSe QDs and considerably exceeds that of organic dyes. A further step in advanced QD-based cancer diagnostics has been made through implementation of efficient FRET-based imaging with 2P excitation, which has been demonstrated for double immunostaining complexes formed on the surface of cancer cells from sdAb-QD conjugates (donor) and a combination of monoclonal Abs and secondary antibodies labeled with the AlexaFluor dye (acceptor). The proposed approach permits obtaining an exceptional contrast of 2P imaging of cancer biomarkers without any contribution of cell and tissue autofluorescence in the recorded images.