Subpicomolar Dopamine Detection Using Two-Dimensional Cobalt Telluride

Abstract

To address the challenges associated with ultrasensitive dopamine sensing for regular health monitoring, here we developed a flexible sensor using two-dimensional cobalt telluride (2D CoTe2). The 2D-CoTe2-coated glassy carbon electrode sensor shows a limit of detection (LoD) of 0.21 pM measured by differential pulse voltammetry (DPV) in 0.1 M phosphate buffer solution (PBS). The assessment of selectivity, repeatability, and reproducibility has been conducted, to enquire about the efficiency of the sensor. The durability of the sensor has been verified for a duration of one month, demonstrating a minimal loss of 16% after a period of one month. The interaction of the 2D CoTe2 and dopamine has been investigated thoroughly by chemical fingerprints using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and Raman imaging, and the adsorption of dopamine on 2D CoTe2 has been confirmed by the theoretical calculations calculating the binding energy, differential charge densities, and projected density of states (pDOS). Additionally, a flexible paper-based sensor using 2D CoTe2 has been successfully fabricated and employed for real-time dopamine detection from artificial sweat, which achieved a LoD of 0.22 pM.