<p>This article describes the spectroscopic and voltammetric properties of a metallodendritic complex (CNTmDCuH) on a carboxylated multi-walled carbon nanotube, as well as its application in the voltammetric detection of thiols compounds such as N-acetylcysteine and L-cysteine. The CNTmDCuH was characterized by spectroscopic and morphological techniques, including Fourier Transform Infrared Spectroscopy (FT-IR), Raman spectroscopy, X-Ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy, surface area /porosity analysis, and cyclic voltammetry. The redox couple (II) showed high sensitivity to N-acetylcysteine and L-cysteine. The analytical curve provided a linear response within the concentration ranges of 5.0 × 10 ⁻⁵ to 1.0 × 10⁻³mol L⁻¹ for N-acetylcysteine and 9.0 × 10⁻⁵ to 1.0 × 10 ⁻³ mol L⁻¹for L-cysteine. The method exhibited limits of detection of 4.13 × 10 ⁻⁵ mol L⁻¹ and 3.3 × 10⁻⁵ mol L⁻¹ for N-acetylcysteine and L-cysteine, respectively.</p>