ИСТИНА

Direct electrochemical detection of double-stranded DNA (dsDNA) may provide a reliable and cost-effective approach to quantify DNA amplification products, with a great potential for coupling to isothermal amplification techniques [1]. The aim of this work was to combine a set of novel 2'-deoxyuridine-5'-triphosphate (dUTP) derivatives modified with Tyr or Trp aromatic groups with polymerase chain reaction (PCR) and isothermal amplification technique such as recombinase polymerase amplification (RPA). For this purpose, dUTP derivatives were tested as electroactive ‘labels’ by square wave voltammetry on carbon screen printed electrodes and as proper substrates for polymerase enzymes in PCR and RPA methods. The ‘labeled’ dUTP nucleotides have demonstrated their oxidation peaks at 0.5–0.7 V, similar to free Tyr or Trp, respectively [2]. Moreover, PCR generated dsDNA fragments with modified nucleotides showed similar oxidation signals at micromolar concentrations, while no peaks were observed for unmodified dsDNA at the same conditions [2]. However, among nucleotides under study, only 5-aminoallyl-dUTP derivative modified with 4-hydroxyphenylacetic acid revealed good compatibility with the RPA assay, probably due to a small size of the additional functional group and linker flexibility. This work was financially supported by the Russian Science Foundation, grant 19-14-00247. 1. Y. Zhao, F. Chen, Q. Li, L. Wang, C. Fan, Chem. Rev. 115 (2015) 12491. 2. E. V. Suprun, S. A. Khmeleva, G. R. Kutdusova, I. F. Duskaev, V. E. Kuznetsova, S. A. Lapa, A. V. Chudinov, S. P. Radko, Electrochim. Acta 362 (2020) 137105.