Improvement of detection of DNA targets using gold nanoparticles in lateral flow assay

Irina Safenkova, A.N. Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian Academy of Sciences, Moscow, Russia (irina.safenkova@gmail.com)
Alexandr Ivanov, A.n. Bach Institute Of Biochemistry, Research Centre Of Biotechnology Of The Russian Academy Of Sciences, Moscow, Russia
Anatoly Zherdev, A.n. Bach Institute Of Biochemistry, Research Centre Of Biotechnology Of The Russian Academy Of Sciences, Moscow, Russia
Boris Dzantiev, A.n. Bach Institute Of Biochemistry, Research Centre Of Biotechnology Of The Russian Academy Of Sciences, Moscow, Russia

Combination of nucleic acid amplification and lateral flow assay (LFA) in one method leads to obtain the highly sensitive tool for rapid non-laboratory ("point-of-care") detection. Amplified DNA oligonucleotides are promising and universal targets for detection of different analytes by LFA based on gold nanoparticle (GNP) labels. The aim of this study is improvement of recognition of DNA oligonucleotides by GNPs on membranes in the systems of flow-through rapid analysis. We produced five types of DNA targets with different lengths (50, 100, 150, 200, 300 bp). Each DNA was functionalized from two ends, 3’-end has biotin, 5’-end has fluorescein. GNPs with diameter of 17.4 ± 1.0 nm were synthesized by citrate reduction method. Sandwich LFA was performed in two versions: 1) antibodies specific to fluorescein are immobilized in the test zone and GNP – streptavidin conjugates recognize DNA – antibody complexes in the test zone; 2) streptavidin affinity binding biotin is immobilized in the test zone and GNP – antibodies specific to fluorescein conjugates recognize DNA – streptavidin complexes in the test zone. We show that scheme with GNP – streptavidin conjugates leads to increase the sensitive from 5 to 30 times that depends on DNA length. The DNA with length of 150 bp was detected at lower concentrations (40 pM). These results demonstrate that the migration of oligonucleotides along the membranes and formation specific complexes depends on the DNA length and scheme of LFA. Effective DNA binding in LFA could be applicable to detect important analytes with high sensitivity for purposes of medicine, veterinary, food quality and safety and environmental control.

This study was financially supported by the RF President Grants for State Support of Young Russian Scientists – PhD (MK-6712.2018.4).

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Short Biography of Presenting Author

Irina V. Safenkova has completed PhD at the age of 26 years from A.N. Bach Institute of Biochemistry, Research Centre of Biotechnology of the Russian Academy of Sciences. She is the senior researcher of Immunochemistry laboratory in Research Centre of Biotechnology. She has published more than 38 papers in reputed journals.