Similarly, the influence of temperature on the maximum response current of the biosensor was evaluated [9], [10], [11], [12] and [25]. Although temperature accelerates enzyme-catalysed reactions, proteins can be denaturalized from certain temperature. Above the optimum temperature, increasing the reaction rate due to temperature is offset by the loss of catalytic activity due to thermal denaturation, and the enzyme activity rapidly decreases until annulled. As it can be seen in Fig. 3, no significant differences are observed at 40 and 50 °C, but the response of the biosensor considerably increases at 60 °C. Thus, the performance of the developed biosensor for sulfite detection and quantification was analysed at 40 and 60 °C. With this aim, several calibration curves were performed, under optimum conditions, using SOx–SPCTTFEs by successive additions of a sulfite solution. The parameters of these regressions were optimally evaluated using the Progress program [26], which builds least median square (LMS) regressions in order to detect the anomalous points. Once, those points were removed from the calibration set, ordinary least square (OLS) regressions were built with the remaining points. This OLS regression provides correct assessment of the slope (sensitivity) and the calibration constant term, both being important for judging the quality of calibration and from this, the analytical method. The slopes of these calibration curves were used to estimate the reproducibility (inter-sensors) of both procedures in terms of relative standard deviation (RSD). It can be seen in Table 3 that the developed biosensor can be used with enough precision for the determination of sulfite in solution at both temperatures, especially considering that are disposable biosensors. Its capability of detection was estimated for a probability of false positive (α) and negative (β) of 0.05 [27] and [28]. The minimum detectable net concentration computed was 4.27 ± 0.27 μM (n = 3) and 1.08 ± 0.23 μM (n = 3), at 40 and 60 °C, respectively. Since these values are below the lowest calibration standard, 9.9 μM at 40 °C and 6 μM at 60 °C, the latter were taken as average capability of detection from an analytical point of view.