A sensor (10,110) is provided for determination of various concentrations of one or more components within a fluid sample. The sensor (10,110) includes an injection molded body (12,112), at least two electrodes (30,31,32,130,131,132), an enzyme (57,157), and, if desired, an electron transfer mediator. The body includes a reaction zone (24,124) for receiving a fluid sample. The electrodes (30,31,32,130,131,132) are at least partially embedded within the plastic body (12,112) and extend into the reaction zone (24,124). Also contained within the reaction zone is an enzyme (57,157) capable of catalyzing a reaction involving a compound within the fluid sample.