“…In early research, cobalt phthalocyanine (CoPc) was recognized for O 2 reduction for low-cost fuel cell applications . Phthalocyanines with different metal centers (e.g., iron, cobalt, copper, nickel, and ruthenium) have been reported to exhibit electrocatalytic activity for electrochemical oxidation or reduction of various biomarkers, molecules, and ions, including glucose, uric acid, lactic acid, paracetamol, creatinine, CO 2 , oxygen evolution reaction, dopamine, ascorbic acid, H 2 O 2 , nitrite, Cd 2+ and Pb 2+ ions, cysteine, and pyridoxine . In this work, we employed copper phthalocyanine tetrasulfonate (CuPcTS) to catalyze cortisol reduction.…”