Instrument-free detection of nucleic acids via gene-targeted four-way-junction sensor coupled with magnetic nanoparticles

Abstract

The detection of nucleic acid (genomic DNA, rRNA, microRNA) is critical for the diagnosis of various diseases and timely treatment. PCR tests and molecular ge- netics are the gold standards in the detection of these nucleic acids, both in the cure of bacterial and viral diseases and for genomic and oncological treatment protocols. However, it usually requires expensive equipment and skilled person- nel. Smart DNA nanosensors with four-way junction can be used as an alter- native to classical methods and offer a cost-effective and easy-to-use diagnostic process. In this study, we developed a four-way junction hybridization sensor to detect the model HigA1 gene responsible for antibiotic resistance in M.tuberculo- sis. The probe has sensitivity up to 100 genomic equivalents (GE) due to its ”long” analytebinding way and increased specificity due to its ”short” complementary way (up to single nucleotide polymorphism (SNP)). Moreover, rapid visible ag- gregation on a streptavidin substrate once the analyte was added was observed. This aggregation was easily detectable by the naked eye. Additionally, dynamic light scattering (DLS) analysis showed a substantial shift in the size range of the complexes formed. Results demonstrate the potential of DNA nanosensors for visually detecting specific analytes, or SNPs for developing affordable and effi- cient diagnostic methods.
The authors are grateful to ITMO University. We also thank the Ministry of educa- tion and science of the Russian federation No FSER-2022-0009 and Priority 2030 program

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Speaker

Maria Berezovskaya
Laboratory of Solution Chemistry of Advanced Materials and Technologies, ITMO university, Saint Petersburg
Russia

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