Catalytic competence of gold clusters decorated yellow 2 G polymer composite film for voltammetric sensing of dopamine and nicotine in biological fluids

A novel, simple, cost-effective, easy-to-prepare, and timesaving electrochemical sensor based on gold clusters decorated yellow 2 G polymer composite film was fabricated and comprehensively characterized for the determination of dopamine and nicotine in real samples. When gold clusters were modified on the yellow 2 G polymer film, a signal increase of 204 % for dopamine and 526 % for nicotine was obtained compared to the activated bare pencil graphite electrode. The signals at 90 mV for dopamine and 780 mV for nicotine were utilized as analytical responses. The fabricated platform serves noteworthy detection sensitivity values of 79.02$\mu A.{\mu M}^{-1}.{\mathrm{cm}}^{-2}$ and 14.61$\mu A.{\mu M}^{-1}.{\mathrm{cm}}^{-2}$ with a notable limit of detection values of 58.8 nM and 7.2 nM for dopamine and nicotine, respectively. The electrochemical method has linear ranges of 0.075–5 µM and 6–10 µM for dopamine alone, 0.01–10 µM and 12–25 µM for nicotine alone, 0.01–10 µM and 12–50 µM for nicotine in the presence of dopamine, 0.2–10 µM and 12–60 µM for dopamine in the presence of nicotine, and 0.4–2, 2–10 and 12–90 µM for dopamine and 0.2–8, 10–20 and 25–90 µM for nicotine at the increasing amounts of each substance. Moving forward, the developed method exhibits splendid accuracy and selectivity for determining dopamine and nicotine in biological samples of human saliva, serum, and urine.