Simultaneous electrochemical detection of L-dopa and hydrogen peroxide by poly (amido amine) dendrimer/poly (neutral red) modified sensor

Abstract

In a biological process, hydrogen peroxide (H2O2) plays an important role as a by-product of enzymatic reactions, and levodopa (L-dopa) is crucial for the production of dopamine in living organisms. These two different chemical compounds are essential for human health, and it is important to monitor their concentration in real samples, for example in the food and pharmaceutical industries. In this research, we fabricated a poly(amidoamine)-dendrimer/poly(neutral red) (PAMAM/PNR) modified electrode and used it to simultaneously determine the electrochemical oxidation of L-dopa and the reduction of H2O2. The PAMAM/PNR-modified sensor electrode showed a linear response from 0.08 to 2400 μM for L-dopa with a LOD (lower limit of detection) of 0.026 μM (S/N = 3). In addition, the PAMAM/PNR modified electrode showed a linear response from 4.6 μM to 2208 μM for H2O2 with an LOD of 1.5 μM (S/N = 3) and using the square wave voltammetry method. The present modified sensor electrode was successfully tested in practical application with beverages and drug samples with acceptable recoveries.