“…A variety of sensing electrode, usually made of platinum and carbon electrodes or their composites, is mainly used for amperometric NO liquid sensing, for example, in the phosphate buffer solution. The electrodes employed include Pt/Nafion ® [1][2], Pt/Nafion ® /cellulose acetate [1], Pt/Ir [3], Pt/poly(4,4'-DHB) [4], C/NiP/Nafion ® [5][6], C/Nafion ® [2,[7][8][9], C/silicon [10], and M(salen)/Nafion ® [11]. Table 1 summarizes the operating condition, NO concentration range, and detection limit in the solution phase studied on various sensing electrodes.…”