A sensor device is adapted to detect glucose concentration in saliva of an object, and includes a conductive substrate, a polymer layer, and a carbon nanomaterial unit. The polymer layer is disposed on the conductive substrate and is made from conducting polymer. The carbon nanomaterial unit is disposed on the polymer layer and includes at least one carbon-nanotube layer. The saliva of the object is applied on the carbon nanomaterial unit and an enzyme is added to be mixed with the saliva to detect the glucose concentration in the saliva. A method for making the sensor device is also provided. |