Sensitive and selective detection of dopamine using electrochemical microfluidic paper-based analytical nanosensor

In this study, electrochemical microfluidic paper-based analytical nanosensor (EμPAN) was used as a sensitive, selective, fast, and low cost technique for dopamine detection. The wax-based stamping technique was used for patterning of microfluidic structure on chromatography paper. A mixture of graphite-chitosan-poly ethylene glycol (PEG) was used as bare working electrode and counter electrode and silver ink was employed as quasi-reference electrode. The electrochemical behavior of these electrodes was investigated using 5 mM K3[Fe(CN)6] in 0.5 M KCl. To enhance the sensitivity and selectivity of the microfluidic-based sensor towards dopamine, multiwall carbon nanotube (CNT), graphene, and Fe3O4 nanoparticles were studied. Compare to other nanomaterials, dopamine was selectively determined using graphene and sodium dodecyl sulfate (SDS) surfactant. The linear range and limit of detection of dopamine were 0.5–120 μM and 0.01 μM, respectively. To show the applicability of the EμPAN, this device was applied for determination of dopamine in blood and urine samples. Keywords: Electrochemical microfluidic paper-based analytical nanosensor, Dopamine, Blood and urine, Sodium dodecyl sulfat