I have a nanohybrids of quantum dots core/shell/shell CdTe/CdS/ZnS coated with GSH and functionalized with phthalocyanines; Zn monocarboxyphenoxy phthalocyanine (1) and Zn tetracarboxyphenoxy phthalocyanine (2).
First of all, you have a very complex system to work with. One can expect multiple Red/Ox couples, which can overlapp or lead to observed results. But most likely this corresponds to the electrochemical oxidation or/and an electrochemical reaction ocurring between your components. Please check this publication, maybe it will give you a hint.