| Abstract [eng] |
Adrenaline (AD) is an important neurotransmitter and hormone that regulates numerous physiological processes in the human body. Altered AD concentrations are associated with various neurological and neuroendocrine disorders; therefore, its sensitive and selective detection is important in clinical diagnostics. Conventional AD analysis methods are accurate; however, they are complex, expensive, and time–consuming, which has encouraged the development of electrochemical sensors characterized by rapid response, simple operation, and low detection limits. The aim of this work was to synthesize PANI–N, B–rGO composites with different compositions and investigate their electrochemical activity toward AD detection. In this study, N–, B– and N, B– modified reduced graphene oxide (rGO) samples were synthesized using hydrothermal and thermal synthesis methods, with the addition of indole and boric acid, respectively. Afterwards, polyaniline (PANI) was synthesized using the oxidative polymerization method. Subsequently, the prepared samples were analyzed using Raman spectroscopy, scanning electron microscopy (SEM), nitrogen adsorption–desorption (BET) and X–ray photoelectron spectroscopy (XPS). The results of the study showed that the most promising sample for the development of an electrochemical sensor is N, B–rGO. Consequently, six suspensions were prepared – N, B–rGO; PANI; PANI–N, B–rGO in a (5–1) ratio; PANI–N, B–rGO in a (1–1) ratio; PANI–N, B–rGO in a (1–5) ratio and PANI–N, B–rGO in a (1–10) ratio. These suspensions were applied to the surface of the glassy carbon electrodes (GCE) and electrochemical measurements were then performed. The differential pulse voltammetry (DPV) study revealed that upon adding adrenaline to the electrochemical cell, an electrochemical response to AD was observed in all samples. The results of the chronoamperometric (ChA) measurements showed that PANI–N, B rGO (1–5) stood out for having the lowest limit of detection (LOD) (28,33 nM) and the widest linear range (0–291 μM). In addition to this sample exhibited good sensitivity (0,388 μA μM–1 cm 2). The selectivity analysis showed a good response of the PANI–N, B–rGO (1–5) electrode to AD and showed no response to the addition of ascorbic acid, citric acid, hydrogen peroxide or D glucose added to the electrochemical cell. The stability and repeatability of the PANI–N, B–rGO electrode (1–5) electrode were also examined. It was determined that this electrode meets the requirements for long–term use and exhibits satisfactory repeatability when used to develop an electrochemical sensor under identical conditions. The results showed that the PANI–N, B–rGO (1 5) composite is a viable option for the development of electrochemical sensors for the detection of AD. |
