Electrochemical Ultra-Low Detection of Isoniazid Using a Salicylaldamine Functionalised G1-DAB-(NH2)4 Dendritic Sensor vs. UV-VIS Spectrophotometric Detection

A poly(propyleneimine) based dendrimer was synthesised and successfully functionalised with a copper centre within its branches. The dendrimer and corresponding metallodendrimer were successfully characterised using FTIR, HR-TEM and HR-SEM in order to determine the effect of the inclusion of copper into the dendritic structure. The incorporation of copper caused crystallinity as revealed in the HR-TEM and a sheet-like morphology as shown in the HR-SEM images. The resulting metallodendrimer was then applied as an electrocatalytic platform for the sensing of a first line TB drug called isoniazid. This method was compared to a routine laboratory detection using UV-Vis and was found to be much more sensitive to trace amounts of isoniazid in solution. The electrochemical detection was found to have a limit of detection (LOD) of 0.233 nM compared to 11.47 nM using the Ultraviolet-visible spectroscopy method.