“…Since the ECL responses of the CdS and luminol are dependent on the H 2 O 2 concentration in PBS, we carried out the experiments to evaluate and obtain the optimal H 2 O 2 concentration. To do this, in QM and AM, the electrode was prepared using 1000 pg.mL −1 thrombin and used as the working electrode in a PBS (0.1 M, pH = 7.5) with different concentrations of H 2 O 2 (5,10,15,20,25,30,35,40 and 50 mM) at 0.1 V. s −1 . The resulted ECL intensities and peaks are presented in Supplementary material, Fig.…”