Electrochemical Determination of Dopamine at Nafion and β-Cyclodextrin-Functionalized Multi-Walled Carbon Nanotubes Composite Modified Glassy Carbon Electrode

Abstract

Dopamine (DA) has been found as a significant neurotransmitter. Since abnormal concentrations of DA can induce a series of serious diseases. Simple, economical and efficient sensors should be developed to detect DA. In this study, a highly selective electrochemical sensor was developed to detect DA using nafion (NA) and multi-walled carbon nanotubes- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -cyclodextrin (MWCNTs- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -CD) composite modified glassy carbon electrode (GCE). The MWCNTs- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -CD composite was prepared by mechanical grinding at ambient temperature, which could be an environment-friendly method. The as-prepared MWCNTs- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -CD composite was characterized with Scanning electron microscopy and Fourier-transform infrared spectra. Such NA/MWCNTs- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -CD/GCE based sensor had high performance with a detection ranges from 0.01 to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1 ~\mu \text{M}$ </tex-math></inline-formula> and from 1 to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10 ~\mu \text{M}$ </tex-math></inline-formula> as well as a detection limit of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.005 ~\mu \text{M}$ </tex-math></inline-formula> . Moreover, the sensor was found with high selectivity, stability, reproducibility and satisfying recovery rate to detect DA in samples. A novel DA sensor was developed with high sensitivity using NA/MWCNTs- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -CD/GCE, which could be promising to detect DA in pharmaceutical samples.