(a) Schematic demonstrating the designing and the detection mechanisms of the ECL-based immunosensor, (b) ECL curves regarding detection of clenbuterol at concentrations equal to a. 1000, b. 50, c. 10, d. 1, e. 0.5, f. 0.02, and g. 0 ng/ml, in pH = 7.4 PBS buffer encompassing 0.1 M K2S2O8 and 0.1 M KCl. Reprinted with permission from Ref. [121], Elsevier.