At Zimmer and Peacock we are delighted if people are interested in developing their sensor or biosensor on a printed circuit board. Their first question is often 'whether it can be commercially done', and the short answer is 'yes' and that there are successful medical diagnostics on the market which use PCBs as the substrate for their electrochemical biosensor.
Before you head off to design your PCB for electrochemical sensor and biosensor applications we would strongly warn you though against some of the pitfalls.
The first questions that ZP would ask is 'what is your application?'. If your application is to make a fast discreet measurement on a sample and then the user would dispose of the sensor then we may agree that a PCB may work for you. If your answer was the the sensor would in place for several hours of continuous measurement then we may warn you away from PCB as the sensor substrate for you.
ZP's second question may be 'how are you exciting your electrode?' If your sensor is using an impedance or potentiometric technique we may suggest that a PCB is suitable for you, but if you replied that you are using an amperometric or voltammetric technique we many suggest you use another type of material for your senor substrate.
We would ask you to contact ZP before going too far with your designs and submitting your Gerber files.