Dear Adel,

please 'google' for by yourself.

So you get familiar with this topic and get a feeling of availability.

There is a very lot of stuff

Dear Gerhard,

Thank you very much. I have searched with google and other and I have not found the accurate and adequate information. Plus, you know well, that is not all published on google or on the internet. As a result, I seek information in any source of information.

Greetings.

Please see for example the link on electro-chemical gas sensor. However there is no voltage output, but this is easily achieved by appropriate electronics. 

A survey on gas sensing technology is given in the second link. Also here analog voltage output , as you required, can be realized by appropriate electronics in may cases.

https://en.wikipedia.org/wiki/Electrochemical_gas_sensor

https://www.mdpi.com/1424-8220/12/7/9635/pdf