Well, in that case it will not work.
The output of this sensor is a low analog voltage of 0..80 millivolts. The best no-extra-circuitry sensitivity from an Aruino is going to be 0..1100 millivolts. Theoretically you could register *something* on an A2D input, but you would not get useful reading data.
Your code needs to be taking A2D input, which it currently is not.
But the biggest problem you have is that the output impedance of that part is gigantic -- you WILL NOT be able to feed that directly into the Arduino A2D or likely into any garden variety op-amp.
Electromotive force (EMF) of the sensor should be measured using a high impedance (>100 G[ch937]) operational amplifier with bias current < 1pA (e.g. Texas Instruments' model #TLC271).
They suggest a specific TI amplifier -- why not go get one of those?