Influence of cationic surfactant cetyltrimethylammonium bromide for electrochemical detection of guanine, uric acid and dopamine

Abstract Frontier molecular orbital and analytical Fukui functions were used to theoretically study cationic surfactant cetyltrimethylammonium bromide (CTAB), predicting its capability for sensitive detection of guanine (GU), uric acid (UA), and dopamine (DA). Herein, we fabricated the CTAB-modified carbon paste electrode (CTCPE), and it exhibited improved sensitivity for the simultaneous detection of three biomolecules, GU, UA, and DA due to the active sites of the CTAB molecules on the electrode surface, which is also proved by our theoretical studies. The CTCPE was used to effectively analyze the various concentration of biomolecules in the mixture containing GU, UA, and DA. The lowest detection limits for the linear range of GU (2–60 μM), UA (5–125 μM), and DA (1–70 μM) have been found to be 0.3, 1.7, and 0.2 μM, respectively. For the detection of target molecules in real samples, such as herring sperm DNA, DA injection, and human blood serum, the CTCPE shows considerably good performance. In our studies, the CTCPE demonstrates good repeatability, stability, and selectivity for detecting GU, UA, and DA with high sensitivity.