# ZnO-modified carbon paste electrode for electrochemical sensing of dopamine in the presence of tyrosine

## TL;DR

This paper introduces a ZnO-modified carbon paste electrode for accurately detecting dopamine in the presence of tyrosine.

## Contribution

The novel contribution is the development of a ZnO nanoparticle-based sensor for sensitive dopamine detection amidst tyrosine.

## Key findings

- ZnO nanoparticles were synthesized via solvothermal method and used to modify a carbon paste electrode.
- The ZnO-modified electrode showed enhanced dopamine oxidation and a detection limit of 0.003 μM.
- The sensor demonstrated high accuracy in detecting dopamine even when tyrosine was present.

## Abstract

Dopamine, 3,4-dihydroxyphenylalanine, functions as a catecholamine neurotransmitter in the brain, sending messages to other neurons to regulate information transmission to other areas of the brain, govern movement, and alter brain activity. Tyrosine undergoes an enzymatic process in the pharmaceutical industry to produce dopamine. Thus, it is crucial to measure both tyrosine and dopamine in bodily fluids simultaneously.

In this work, we demonstrate the production of ZnO nanoparticles using a straightforward solvothermal technique. A straightforward, quick, and sensitive electrochemical sensing platform for dopamine detection was then created using the produced ZnO nanoparticles.

Cyclic voltammetry comparison revealed that the ZnO/carbon paste electrode considerably enhanced the dopamine oxidation process compared to the unmodified carbon paste electrode (CPE). With a low detection limit of 0.003 μM, the ZnO/CPE sensor's linear response for voltammetric dopamine determination was found to be between 0.01 and 480.0 μM.

The modified CPE effectively demonstrates its great accuracy in tyrosine-induced dopamine detection.