Quantum dots modification for analytical test-methods
Olga A Goryacheva, Daria V Tsyupka, Ekaterina A Mordovina, Svetlana A Meshcheryakova, Danila A Kornilov, Daniil D Drozd, Yuliya A Podkolodnaya, Irina Yu Goryacheva
Saratov State University 410012, Astrakhaskaya 83, Saratov, Russia
Abstract
Wide area of analytical test-methods has a big needs in the uniform stable label with easy-going modification process and low influence on the sensitivity and methods representation. Semiconductor nanocrystals with unique optical properties, also known as quantum dots (QDs), have all advantages to replace classical organic molecules. Wide excitation spectrum with optional fluorescence wavelength, physical stability and ability to surface modification allow to make conjugates with antibodies for wide range of antigens. Different QDs architecture and compounds create the conjugates which can be applied in heterogenic and homogenic immunoassay with different timeline from classical ELISA protocol to fast lateral flow test.
QDs synthesized via high-temperature organometallic methods exhibit tunable fluorescence properties ideal for biosensing applications. To enhance their biocompatibility, hydrophobic QDs are hydrophilized through reverse microemulsion, enabling surface functionalization with various groups (e.g., carboxyl, amine) for subsequent conjugation to antibodies or other biomolecules. By employing QDs with distinct emission wavelengths, a single test strip can simultaneously detect multiple analytes, significantly improving diagnostic efficiency in LFIA. For low-molecular-weight analytes, QDs coated with a thin polymer layer can interact with gold nanoparticles via Förster Resonance Energy Transfer (FRET). Upon antigen-antibody binding, fluorescence quenching occurs, providing a measurable signal. This FRET-based mechanism facilitates homogeneous immunoassay, adaptable to high-throughput screening in 96- or 384-well plates. Additionally, surface modification with thioglycolic acid renders QDs sensitive to specific molecules. Analyte adsorption induces fluorescence quenching, making these QDs promising for extrusion-based rapid tests.
The study was funded by the Russian Science Foundation: project number 21-73-10046.
Speaker
Olga A. Goryacheva
Saratov State University
Russia
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