Quantitative Assessment of Chl a and b in Spinach Chl Standard Solution Using a Filter-free Wavelength Sensor

We proposed a quantitative method for assessing chlorophyll (Chl) content and Chl a/b ratio using a filter-free wavelength sensor.Initially, an experiment was conducted to simulate changes in Chl a and b by adjusting the light intensity at wavelengths of 650 and 660 nm.The sensor's output current ratio exhibited a linear relationship with the light intensity, suggesting its potential for measuring Chl.Subsequently, measurements were performed using standard Chl a and b solutions.A strong linear correlation was observed between sensor output and Chl content, independent of changes in Chl a/b ratio.However, no direct correlation was found between sensor output and Chl a/b ratio.This inconsistency was attributed to the varying impact of Chl content changes on the sensor output, depending on the specific Chl a/b ratio.To address this limitation, we proposed a calibration method based on the relationship between Chl content and sensor output.By applying this calibration curve, we successfully reduced the error in Chl a/b ratio measurements.This approach enables the use of filter-free wavelength sensors for the accurate quantification of Chl content and Chl a/b ratio, offering a potential solution for on-site monitoring and agricultural applications.