Determination of Limit of Detection in Electrochemical Biosensors

one of the important parameters determining the quality of an electrochemical biosensor is the limit of detection (LOD). A definition of this parameter is given by the International Union of Pure and Applied Chemistry (IUPAC). Different approaches are known for calculating the LOD in different types of biosensors, each of which comes with advantages, disadvantages and limitations. Three methods are mainly applied to determine LOD from experimental data from low concentration standard deviations, from a calibration curve, and from instrument resolution. The calibration curve method was used to determine the LOD in amperometric electrochemical biosensors. Experimental data from really developed electrochemical biosensors - plant-tissue and enzyme-based - were used to perform the calculations. The resulting values for sensitivity and LOD are b=2.97mM/mg$O_{2}$/1, SLOD =0.206 mM for plant-tissue biosensor and b=3.1mM/mg$O_{2}$/1, $S_{LOD}$ =0.176 mM for enzyme-based biosensor. The calibration curve method can be used as a useful tool for preliminary indicative quality analysis of a amperometric electrochemical biosensor.