Table 1.

Main figures of merit used to validate sensors and biosensors [3], [17]

Figure of merit	Definition
Sensitivity	Slope of the analytical calibration curve. An analytical method is sensitive when a small change in analyte concentration causes a large change in response.
Selectivity	Ratio of the slopes of the calibration lines of the analyte of interest and a particular interference. A method is selective when the response of the analyte can be differentiated from every other response.
LOD	Concentration or the quantity derived from the smallest signal that can be detected with acceptable degree of certainty for a given analytical procedure.
Repeatability	Closeness of the agreement between successive measurements of the same parameter, which were carried out in the same conditions related to operators, apparatus, laboratories and/or intervals of time analysis.
Reproducibility	Closeness of the agreement between successive measurements of the same parameter, performed in different conditions in terms of operators, apparatus, laboratories and/or intervals of time analysis.
Signal-to-noise ratio	Ratio of the useful analytical signal to the background noise, which is identified as a measure of the statistical fluctuations in a blank signal.