Voltammetry and electrochemical impedance spectroscopy of gold electrodes modified with CdTe quantum dots and their conjugates with nickel tetraamino phthalocyanine

This work reports on the synthesis of conjugates of cadmium telluride quantum dots (CdTe-QDs) caped with thioglycolic acid and peripherally substituted nickel tetraamino phthalocyanine (NiTAPc) complex. The conjugates are characterized using cyclic (CV) and differential pulse (DPV) voltammetries, electrochemical impedance spectroscopy, X-ray powder diffraction, infrared spectroscopy, Raman spectroscopy, atomic force microscopy and time correlated single photon counting. CV and DPV show that NiTAPc stabilizes the CdTe QDs against oxidation to metallic products.

Cyclic and differential pulse voltammetry shows that conjugates of cadmium telluride quantum dots caped with thioglycolic acid and peripherally substituted nickel tetraamino phthalocyanine are more stable against oxidation to metallic products compared to quantum dots alone.Figure optionsDownload as PowerPoint slideHighlights
► Nickel tetraamino phthalocyanine is covalently linked to quantum dots.
► Cyclic voltammograms of quantum dots alone or when conjugated to quantum dots are studied.
► Nickel tetraamino phthalocyanine improves the stability of quantum dots towards oxidation to metallic products.
► Nickel tetraamino phthalocyanine monomerizes quantum dots.