Rapid response sensor for carbon monoxide

An electrochemical sensor for a chemical species, which chemical species is a contaminant in a fluid stream, said sensor comprising:

• a fuel cell, said fuel cell having an anode and an anode catalyst facilitating a chemical reaction in a component of a fluid stream, said anode catalyst being capable of being poisoned by a contaminant in said fluid stream;
• an electrical circuit, said circuit having a voltage source, a variable resistor and a monitor;
• said voltage source and variable resistor operable to provide an overvoltage to said anode of said fuel cell;
• and
• said monitor operable to detect and monitor a time-dependent response of said anode to said overvoltage,
• the time-dependent response being correlatable to a contaminant bound to said anode catalyst.

A method for detecting the presence and/or a concentration of a contaminant within a fluid stream, the method comprising:

• exposing a catalyst to a fluid stream, the fluid stream having a contaminant therein, the contaminant poisoning the catalyst;
• applying a stimulus to the catalyst;
• and
• monitoring the time-dependent catalyst performance to the stimulus, the time-dependent catalyst performance being correlatable to presence and/or concentration of the contaminant bound to the catalyst.