A portable electrochemical sensor for simultaneous voltammetric determination of multiple neurotransmitters using...

A portable electrochemical sensor for simultaneous voltammetric determination of acetylcholine (Ach), serotonin (5-HT) and dopamine (DA) using magnetic multi-walled carbon nanotubes-decorated ferroferric oxide-Pt@Au nanoparticles (FM-Pt@AuNPs) composite nanozyme was developed. The application of the nanozyme perfectly solved the problem of the weak electroactivity of Ach and the overlapping electrochemical signal of 5-HT and DA. Benefiting from superior horseradish peroxidase (HRP)-like activity and huge specific surface area of the FM-Pt@AuNPs, the proposed sensor enabled to quantify ACh, 5-HT, and DA at the potential of + 0.9, + 0.35, and + 0.14 V, with detection limits of 2 nM, 15 nM, and 10 nM, respectively. The assay provides good analytical performances and clinical practicability in human serums samples. This is the first detection of Ach, 5-HT, and DA using voltammetry, and it is also a new attempt of nanozyme in the field of portable electrochemical sensors. The strategy could be used for detecting other small biomolecules, and provide a simple and potential way for early-stage diagnosis and management of neurological diseases.