Laboratory of Nano-Bioengineering wins 2020 Russian Science Foundation grant competition with project on designing low-toxic quantum dots for biomedical applications

The project on Cd-Free Nanocrystals Based on Copper Indium Sulfide and Silver Indium Sulfide Luminescing in the Visible and NIR Spectral Region with High Fluorescence Quantum Yields (CdFreeQuant) by Pavel Samokhvalov, Ph.D., head of the Nanochemistry Group of LNBE, NRNU MEPhI, and Professor Igor Nabiev, Ph.D., D.Sci., leading scientist of this laboratory, has won the competition for grants of the Russian Science Foundation in the priority area Basic Research and Exploratory Studies Carried out by Single Research Groups.

 

The implementation of this project will meet the pressing need of modern medical diagnosis for highly sensitive and specific but nontoxic nonoprobes for early simultaneous detection of multiple cancer biomarkers.

Today, probes based on the so-called quantum dots, a type of fluorescent nanocrystals, are becoming increasingly popular in bioimaging. They have distinct comparative advantages over organic dyes, including bright photoluminescence in a very narrow spectral range and a high quantum yield, as well as a high photostability. Furthermore, it is possible to detect several markers at a time by using different quantum dots with nonoverlapping spectral ranges of luminescence excited at the same wavelength. However, a regular "traditional" quantum dot contains cadmium, which, being a heavy metal, is highly toxic. This precludes the use of such nanocrystals in vivo ("in the living body"). Attempts are undertaken to synthesize quantum dots from low-toxic materials, but the optical properties of the resultant nanocrystals are much inferior to those of the currently available cadmium-containing quantum dots.

The CdFreeQuant project will result in cadmium-free quantum dots with CuInS2 and AgInS2 cores, reliable methods for their reproducible synthesis, and complete list of their photoluminescence characteristics. Optimal surface ligands will be selected to ensure solubility of these quantum dots in biological fluids. The resultant biocompatible quantum dots will be linked to the so-called single-domain antibodies (ultrasmall antibody fragments) against several markers of malignant tumors. This will yield nanoprobes for multiplexed detection of several types of cancer markers in tissue samples, which will substantially enhance the sensitivity and accuracy of histological analysis in cancer diagnosis. The detection of biomarkers will be all the more reliable as these quantum dots fluoresce in the infrared spectral region coinciding with the "transparency window" of living tissues, allowing the markers to be detected in bulk tissue sections or in the living body. Within the CdFreeQuant project, the new nanoprobes will be developed up to the stage of preclinical trials on tissue specimens from cancer patients. In the future, these or similar probes will be applicable to noninvasive in vivo diagnosis.

As a result, the project will yield a next generation of safe-to-use diagnostic tools that require an order of magnitude less clinical material for simultaneous detection of a variety of diagnostic markers. The results of the project will be important for practical applications of cadmium-free quantum dots not only in medicine, but also in other fields, such as optoelectronics and photovoltaics. The experimental data obtained during the project will subsequently make it possible to optimize the size and shape of the new quantum dots and the composition of their surface ligands for each potential field of their use.

Contacts:

Maria G. Korenkova, director of public relations (MGKorenkova@mephi.ru)

Pavel S. Samokvalov, Ph.D., senior researcher (p.samokhvalov@gmail.com)

Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI,
31 Kashirskoe shosse, 115409 Moscow, Russian Federation

http://lnbe.mephi.ru/en

 
 
 
© 2012 Laboratory of Nano-BioEngineering