In general, one takes 3 times the standard deviation of the blank signal or the noise level. This means your analyte’s signal must be sufficiently larger than the variations of the blanks or the stability of your base line. Often the applied method is extremely sensitive but the blanks (your reagents) are determining the effective LOD.
Generally LOD is calculated from 3Sbl/m, Sbl is the standard deviation of blank solution and m is the slope of the calibration curve. sensitivity is calculated from slope of the calibration curve divided by area of the electrode ( in some cases the electrochemical active surface area).
Lavanya jo take care of meaning of LOD .... Usually this means limit of detection and in this case s/n equal or larger than 3 is the right figure
On the contrary, if LOD means limit of determination the right figure increases up to 10
Please don't confuse LOD with sensitivity ... sensitivity is the slope of the linear correlation between your signal and the analyte level
hope this help
Yes. it is the standard deviation without the addition of analyte.
thats fine . .I have calculated blank standard deviation 0.2058.
slope is coming around 3.34
after calculation by (3*standard deviation)/slope = 0.20
now how to tell the unit of this?
will it be in milimolar or micromolar or nanomolar.
In calibration curve x axis was in milimolar (mM).
so it will be in milimolar or something else?
please explain.
Would it be correct to calculate Limit of detection and Sensitivity of a biosensor/bioelectrode using Cyclic voltammetry in unstirred solution?
Sir, as you have mentioned in the above comments regarding sensitivity calculation of an electrochemical sensor, can you kindly suggest me with relevant papers wherein they have calculated sensitivity? Siva Subramanian
It is the slope of the calibration curve divided by the area of electrode. So (unit of current)/(unit of concentration*unit of area) e.g. μA/μM·cm2 depending upon the scale of unit.
- Badges
- Science topic
- Similar topics
- Biological Science
- Bioecology
- Systems Ecology
- Landscape Ecology
- Connectivity