Rapid voltammetric determination of hemagglutinin in saliva using magnetic nanoparticles modified with triazolotriazine in a portable cell design

Abstract

Express determination of the viral nature of the diseases is one of the most important tasks of modern medicine. Portable electrochemicalanalytical devices are used to complement standard laboratory analytical methods and implement analysis at the patient's bedside. A rapid approach of voltammetric determination of the viral marker protein hemagglutinin (НA) in saliva using portable electrochemical microcell based on the three-electrode planar system (TPS) and magnetite nanoparticles modified with 3-nitro-4‑hydroxy-1,4-dihydro-7-propargylthio-1,2,4-triazolo[5,1-c][1,2,4]triazine (MNPs-Aza) was developed. MNPs-Aza were synthesized by carbodiimide cross-linking and characterized by infrared spectroscopy and square wave voltammetry. Modified MNPs were used simultaneously as carriers of the HA receptor and as agents for HA-Aza complexes concentrating on the surface of the working electrode. The normalized difference between the peak current values of the first stage of electroreduction of Aza before and after selective interaction with the HA in the analyzed sample (I*) was used as the analytical signal. Under the selected operating conditions of the developed portable microcell, linear calibration I* = (12.81±0.26) lg сHA + (136.75±1.73) was obtained in the range of 10–3–10–9 M. The limit of detection (LOD) calculated by the 3σ criteria was 8.4·10–10 M. The developed approach was successfully tested on model solutions and real saliva samples.