A conducting poly(N-(1-Naphthyl)ethylenediamine dihydrochloride) nanofibers for the sensitive and interference-free detection of dopamine

This research demonstrated the development of a stable, sensitive, and selective electrochemical method based on poly(N-(1Naphthyl) ethylenediamine dihydrochloride) nanofibers-modified anodized glassy carbon electrode (PNEDA/AGCE) for the detection of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA). The PNEDA/AGCE sensor could easily separate the oxidation signals of AA, DA, and UA from their mixture solution in PBS (pH 7.0). It showed linear behavior over wide concentration ranges for DA sensing and the detection limits were ca. 0.070 and 0.075 μM in PBS (pH 7.0) and diluted human serum samples respectively, while the sensitivities were ca. 0.085 and 0.080 μA.μM−¹, respectively. The high sensitivity for the PNEDA/AGCE sensor can be ascribed to the facile H-bonding interaction between the free –NH₂ groups of PNEDA and oxidizable –OH groups of DA, which was verified by Gradient-corrected density functional theory (DFT) calculation. The PNEDA/AGCE sensor showed excellent repeatability and reproducibility with very low RSD (%) and excellent recoveries of DA concentrations in human serum samples.