“…The disease, which results from insulin deficiency, is one of the leading causes of death and disability [1]. Millions of diabetic in sensing application due to their outstanding properties such as low cost, excellent semi-conductivity, and good biocompatibility [12][13][14][15][16][17][18]. Among various kinds of transition metal oxides, Co 3 O 4 shows intriguing electronic, electrochemical, and electro-catalytic properties.…”