TY - JOUR AU - Arakelyan, V. B. AU - Karapetyan, A. T. AU - Vardevanyan, P. O. PY - 2019/06/06 Y2 - 2024/03/29 TI - Influence of adsorption of ligands on output signal of DNA-biosensor JF - Biophysical Bulletin JA - Bioph. Bull. VL - 0 IS - 42 SE - Molecular biophysics DO - 10.26565/2075-3810-2019-42-05 UR - https://periodicals.karazin.ua/biophysvisnyk/article/view/11436 SP - 61-67 AB - Background: The important advantage of the application of DNA-biosensors as compared to traditional molecular-biological methods is connected to the miniaturization of the studied samples and analyzers, which significantly decreases the analysis value as well as the time of its realization. Though, the miniaturization inevitably results in both decreasing the DNA-biosensor output signal value and increasing the noise signal level. That is why the studies devoted to the influence of different factors, particularly ligands on the output signal value and noise level of DNA-biosensors become actual tasks.Objectives: To theoretically calculate the dependence of DNA-biosensor output signal on the concentration of ligands in the solution. To study the characteristic peculiarities of DNA-biosensor output signal.Theory: The model, in the frame of which the theoretical calculations were carried out, is described here. There is an underlayer, on which the single-stranded molecules of DNA-targets are immobilized. The underlayer borders on the solution, where there are both single-stranded DNA molecules complementary to DNA-targets and ligands able to be adsorbed on DNA duplexes. The value of output signal DNA-biosensor is proportional to the number of DNA duplexes. Adsorption of ligands on DNA duplexes results in changing the output signal of DNA-biosensor. It is accepted that the adsorbed ligand enhances DNA-biosensor output signal. Taking into account that the formation and decomposition of the complex of ligands with DNA duplex occur in a random way, the number of bound ligands to DNA duplexes will change randomly as well, which will inevitably result in DNA-biosensor output signal fluctuations.Results: It has been shown that along with increasing the concentration of ligands in the solution the output signal of DNA-biosensors rises monotonously and the relaxation time of the output signal decreases. It was also shown that the output signal dispersion of DNA-biosensor increases at first with the concentration increase of ligands in the solution, then passing through the maximum decreases and tends to zero at the further concentration enhancement of ligands in the solution.Conclusions: The obtained data can be applied practically in the preparation of micro DNA-biosensors and analysis of the measurement results.  ER -