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

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 mu M), UA (5-125 mu M), and DA (1-70 mu M) have been found to be 0.3, 1.7, and 0.2 mu M, 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. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

By theoretically studying the frontier molecular orbital and analytical Fukui functions, a CTAB-modified carbon paste electrode (CTCPE) with improved sensitivity for simultaneous detection of guanine, uric acid, and dopamine was successfully fabricated. The electrode demonstrated low detection limits for the biomolecules in mixture and showed good performance for detecting target molecules in real samples. The CTCPE exhibited good repeatability, stability, and selectivity for detecting GU, UA, and DA with high sensitivity.