Synergistic Amplification Signal Based on CoNPs and Melamine for Simultaneous Quantification of Epinephrine and Serotonin

Abstract

Here we report an electrochemical sensor for the detection of epinephrine (EP) and serotonin (5-HT), two important neurotransmitters in the mammalian central nervous system, which are also present in serum. Their concentration will affect the psychological and physiological activities of the human body, especially in regulating emotions. Therefore, it is very important to detect EP and 5-HT simultaneously. Herein, cobalt nanoparticles (CoNPs) and melamine (MEL) were deposited on a glassy carbon electrode (GCE) by cyclic voltammetry (CV), resulting in an electrochemical sensor (MEL/CoNPs/GCE) that allowed the detection of both EP (0.23 V) and 5-HT (0.38 V vs. Ag/AgCl). Square wave voltammetry (SWV) measurements allowed us to establish a linear range of EP and 5-HT in the range of 5.00 to 500.00 μmol·l−1, with a limit of detection of 1.60 μmol·l−1 for EP, and of 2.52 μmol·l−1 for 5-HT. The detection sensitivity were 1.38 and 1.62 μA·μM−1·cm−2 for EP and 5-HT. Finally, the sensor also was used to detect serum with a recovery of 92.8% to 98.2% for EP, 98.7% to 99.0% for 5-HT, with RSD of 3.3%, indicated that it can be used for the rapid and simultaneous detection of EP and 5-HT.