Systems and methods for determinig sample osmolarity

A system comprising:

• (i) a sensor comprising a sensing surface comprising a coated region, wherein the sensor is configured to:
• direct a first optical signal to interact with the sensing surface at a first incident angle;
• and
• direct a second optical signal to interact with the sensing surface at a second incident angle;
• and
• (ii) an optical chassis comprising:
• an optical signal generating component;
• a detection component;
• a processor;
• a controller;
• and
• a computer-readable medium comprising instructions that, when executed by the processor, cause the controller to:
• direct an optical signal having a first wavelength to interact with the sensing surface at the first incident angle to generate a first surface plasmon resonance (SPR) signal;
• generate a series of images of the first SPR signal over a first time interval using the detection component;
• determine a series of pixel positions that correspond to a minimum value of the first SPR signal over the first time interval;
• direct an optical signal having a second wavelength to interact with the sensing surface at the first incident angle to generate a second SPR signal;
• generate a series of images of the second SPR signal over a second time interval using the detection component;
• determine a series of pixel positions that correspond to a minimum value of the second SPR signal over the second time interval;
• compare the series of pixel positions that correspond to the minimum value of the first SPR signal over the first time interval to the pixel position of at least one reference feature to generate a first reference-corrected SPR function;
• compare the series of pixel positions that correspond to the minimum value of the second SPR signal over the second time interval to the pixel position of the at least one reference feature to generate a second reference-corrected SPR function;
• and
• compare one or more characteristics of the first reference-corrected SPR function and the second reference-corrected SPR function to determine a reference-corrected SPR delta pixel value.