Patent ID: 8431001

Claim:
An ion sensor for measuring ion concentration of a solution, comprising: a conductive base structure including a substrate and an electrode film formed on said substrate and having a sensing region; a plurality of ion-sensitive nanorods protruding from one side of said electrode film opposite to said substrate, covering entirely said sensing region of said electrode film, and exhibiting an ion selectivity of absorbing an ion of interest thereon for inducing a surface potential corresponding to concentration of the ion of interest in the solution; and an encapsulant of an insulator enclosing said conductive base structure except for said sensing region of said electrode film and formed with a window for exposing said ion-sensitive nanorods to the solution, wherein each of said ion-sensitive nanorods has a conductive core made from an electrically conductive material and protruding from said electrode film, and an ion-sensitive layer formed on and enclosing said conductive core and made from an ion-sensitive material different from said electrically conductive material, said ion-sensitive material exhibiting the ion selectivity, and wherein said electrically conductive material is indium tin oxide, tin oxide, or indium oxide.