An electrode for measuring the presence of a subject is described as an embodiment. The electrode comprises a working conductor having an electrode-reactive surface and a first reactive chemical that is sensitive to the subject. The electrodes further include a first transport material that allows the first subject to flow to the first reactive chemical and a second transport material that supplies the reactant to the first reactive chemical. And include. In this case, the first reactive chemical does not come into contact with the electrode-reactive surface, while at least partially occulting the electrode-reactive surface. [Selection diagram] Fig. 1A【解決手段】 被検体の存在を測定する電極が、一実施形態として記載される。電極は、電極反応性表面を有する作用伝導体と、被検体に感度を有する第１の反応性化学物質とを含む。電極はさらに、第１の反応性化学物質への第１の被検体の流束を可能にする第１の輸送材料と、第１の反応性化学物質に反応物質を供給する第２の輸送材料とを含む。この場合、第１の反応性化学物質は電極反応性表面に接触しない一方、電極反応性表面の一部分を少なくとも部分的に掩蔽する。【選択図】 図1Ａ
