Coupling surfactants with 3D hollow raspberry-like NiS/carbon microsphere with S vacancies for enhanced sensitivity monitoring of serotonin and L-tryptophan

Abstract

Serotonin (ST) is a monoamine neurotransmitter synthesized from L-tryptophan (L-Try). Solving their simultaneous detection problem is necessary for assisting in diagnostics diseases. In this work, we designed NiS/carbon hybrids with NiS nanoparticles embedded on 3D hollow porous carbon microspheres (NiS/CS) via successive carbonization and sulfidation Ni-MOF for constructing electrocatalysts for the simultaneous electrooxidation of ST and L-Try. The formation of robust contact with surface S vacancies in NiS/CS nanointerfaces demonstrated a remarkably enhanced electrocatalytic activity towards ST and L-Try and the corresponding electrochemical signals appeared as two well resolved oxidation peaks with the significant peak-to-peak separation. Importantly, the dual amplification effect of the high electrocatalytic performance function of NiS/CS and the hydrophobic properties of surfactant CTAB coupling made CTAB/NiS/CS/GCE exhibit high sensitivity recognition to ST and L-Try, effectively shielding other coexisting interference. The developed sensor provided a 0.01–200.0 μmol/L linear response range and the low detection limit of 3.35 and 2.94 nmol/L for ST and L-Try, respectively. Finally, this sensing methodology enabled accurate determination of ST and L-Try amount in serum, urine and injection samples and with successful recovery outcomes.