CC BY
12LD-I-7
Study of colloidal suspensions of carbon nanoparticles using fluorescence, Raman and CARS spectroscopy
S. Burikov1, K. Laptinskiy2, T. Dolenko1
1- Department of Physics, Lomonosov Moscow State University, Leninskie Gory 1/2, 119991 Moscow, Russia 2- Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Leninsky Gory 1/2, 119991 Moscow, Russia
Carbon nanoparticles (CNP), primarily nanodiamonds (ND), carbon quantum dots, and complexes based on them, have a whole set of properties that make them very promising in terms of applications in biomedical applications [1]. They are non-toxic, biocompatible, have a developed multifunctional surface, and they have stable and intense luminescence. Therefore, CNP can be used as drug carriers, luminescent markers, and adsorbents.
One of the key issues related to the prospects of using CNP in biomedicine is the question of their interactions in suspensions with water molecules and biomacromolecules - proteins, DNA, etc. On the one hand, these interactions can affect certain properties of the CNP, on the other hand, the CNP itself can influence the components of the biological environment. It has been found that CNP significantly alter the hydrogen bonds between water molecules in suspensions. At the same time, the properties of the CNP themselves depend on the strength of the hydrogen bonds in the suspensions. Thus, Raman spectroscopy and luminescence spectroscopy were used to determine the dependences of the luminescent properties of the CNP on the strength of hydrogen bonds between water molecules in suspensions and the efficiency of interaction with biomacromolecules [2].
An important practical application of CNP is their use as luminescent markers. At the same time, a serious problem is the separation of the useful luminescence signal of the marker against the background of intense broadband luminescence of the biological environment (autoluminescence). In order to solve this problem, machine learning methods, in particular, artificial neural networks (ANN), are successfully used. ANN, due to such properties as resistance to noise and the ability to learn on patterns, have proved to be an indispensable tool for solving this problem [3].
Another approach to solving the problem of CNP visualization in the biological environment is the use of CARS (Coherent Anti-Stokes Raman scattering) spectroscopy. Due to the fact that the CARS signal is located in the anti-Stokes region of the spectrum, the problem of distinguishing the useful signal against the background of autoluminescence is eliminated. CARS spectroscopy has also been successfully used to study the interactions of ND with protein molecules.
At the current stage of development of researches in this field, it can be argued that the combination of various spectroscopy methods - fluorescence spectroscopy, Raman spectroscopy, and CARS spectroscopy - allows one to obtain information about the processes occurring in colloidal suspensions of CNP, about their interactions with environmental molecules, and about the properties of CNP in suspensions and biological media.
This study was supported by the Russian Science Foundation (Project no. 20-72-00144).
[1] J.M. Rosenholm, I.I. Vlasov, S.A. Burikov, T.A. Dolenko, O.A. Shenderova, Nanodiamond-Based Composite Structures for Biomedical Imaging and Drug Delivery, Journal of Nanoscience and Nanotechnology 15(2), 959-971 (2015)
[2] K.A. Laptinskiy, E.N. Vervald, A.N. Bokarev, S.A. Burikov, M.D. Torelli, O.A. Shenderova, I.L. Plastun, T.A. Dolenko, Adsorption of DNA Nitrogenous Bases on Nanodiamond Particles: Theory and Experiment, The Journal of Physical Chemistry C 122(20), 11066-11075 (2018).
[3] O.E. Sarmanova, S.A. Burikov, S.A. Dolenko, I.V. Isaev, K.A. Laptinskiy, N. Prabhakar, D. Karaman, J.M. Rosenholm, O.A. Shenderova, T.A. Dolenko, A method for optical imaging and monitoring of the excretion of fluorescent nanocomposites from the body using artificial neural networks, Nanomedicine: Nanotechnology, Biology and Medicine 14(4), 1371-1380 (2018).
