Some inuencing parameters, such as pH, content of K2S2O8 and binding time between the Con A and glucose, have been studied in this work. As indicated in Fig. 4A, the pH of PBS buer range from 6.0 to 8.5 is investigated, and the strongest luminescent signal appears at 7.4 because high or low pH will have an adverse impact on the immobilized process of protein. Thus, near-neutral pH (7.4) is selected as the optimal pH. As the concentration of K2S2O8 is constantly rising from 0.01 M to 0.1 M, the