Figure of merit of sensor for biomedical application depends on Sensitivity FWHM Selectivity both a and b

The figure of merit for a sensor in biomedical applications depends on several factors. These include:

1. Sensitivity: This refers to the sensor's ability to detect small changes in the quantity it is measuring. A sensor with high sensitivity will produce a larger output signal for a given change in the input quantity.

2. Full Width at Half Maximum (FWHM): This is a measure of the spread of a signal or function, most commonly in spectroscopy and signal processing. It is the difference between the two values of the independent variable at which the dependent variable is half of its maximum value. In the context of sensors, it can be related to the resolution of the sensor.

3. Selectivity: This refers to the sensor's ability to specifically and selectively respond to the target analyte, while being unresponsive or significantly less responsive to other non-target analytes.

4. Both Sensitivity and FWHM: The figure of merit for a sensor could depend on both these factors. A sensor with high sensitivity and low FWHM would be ideal as it would be able to detect small changes in the input quantity and have a high resolution.

So, the answer to your question is both a and b - Sensitivity and FWHM.