This is a clear proof that the performance and limitations of enzymatic electrochemical sensors cannot be analyzed using approaches developed for homogeneous solutions even in the most simple MM case. This is a very important result of the above analysis. Indeed, to evaluate the performance and limitation of electrochemical bioenzymatic sensors one often uses double reciprocal plots expecting them to be linear for a well-behaving sensor and try to extract slopes (supposedly 𝐾 /𝑉 values) and intercepts (supposedly 1/𝑉 ) values to characterize their sensors . Furthermore, Fig. shows that unless 𝜎 = 0 the intercepts of 𝑖 /𝑖 are significantly smaller than unity which is a theoretical non-sense since by definition 𝑖 /𝑖 ≥ 1. Therefore, except when 𝜎 = 0, i.e., when mass transport is excessively fast compared to enzymatic kinetics the usual double reciprocal diagrams provide misleading information. Note also that when 𝜎 = 0, (black curves in Fis.3a-c), one has