You will have many problems here as each polymer chain has a different length and so different number of chromophores. They interact differently because of there (self) aggregation etc and you can have multiple excitations per chain. It's a difficult problem to quantitatively address. For well isolated chains in solution and solid state SV can be used and give straight lines. See the papers on the subject by Al'Attar and myself as a guide.

I also got a S-V characteristic stright line plot for Co and Fe. bit confused to see how the collective quenching property is acting here.

Thanks Andy Monkman and for the reference also.

The stern-volmer relationship is really just looking at the concentration dependence of the response.  It can be used as a unit less comparison if you were comparing different technologies or say comparing a single technology but different sensing materials to a specific analyte.

Whatever your sensor may be setup an experiment which varies the concentration of analyte to the sensor.  Allow enough exposure time for the sensor response to saturate for each concentration.  Once you have this data get the change for each response (Io/I).  The standard equation is Io/I=1+Ksv[Q], where Q is the concentration and Ksv is the slope of the line that fits to the points you just found.