What I know there are 2 ways Δθ/Δn and sensogram curve. Is there first way will be enough? or second way will be better? or 2 of them are important? Many thanks for help.
In case of the sensitivity measurement we need the difference of refractive index xorresponding change in the resonance wavelength.
The sensitivity measurement in SPR depends on what you want to measure. If you are interested by the bulk refractive index sensitivity, a series of sucrose or NaCl solutions of known refractive index is the best way to measure it. You can then fit a linear regression of the change in resonant angle or wavelength (depending on your instrument) and extract the slope or sensitivity. You may also be interested in measuring the penetration depth and thus, the surface sensitivity of your SPR sensor. In that case, you can use layer-by-layer deposition of polyelectrolytes. The increase in SPR signal as a function of increasing layer thickness will provide a measure of the surface sensitivity.
The 2 suggested methodologies are both important. The angle/refractive index measurement (measured by sucrose solutions) is usually expressed as figure of merit (FOM) and is an indication of SNR.
The sensorgram is off course related to the SNR of your SPR sensor, however as the signal will not change over time (or shouldn't) there's not much additional information in it. The relevant application of a sensorgram is to evaluate your functionalization on the sensor surface. So usually this would be your recognition element (such as antibody - antigen interaction). By measuring multiple concentrations of an e.g. biological interaction while both binding and dissociating you can determine the dissociation constant, the SNR and LOD of this interaction.
Ya all of right the definition always depend upon the parameter what you are measuring since in spr different type of sensor reported then the sensitivity we have to be calculated on the basis what we are going measure or what is the parameter we are going to measure.
- Badges
- Science topic
- Similar topics
- Papers