Development of a Portable Optical Sensor for Low-Concentration Copper Sulfate Detection in Water

Currently, spectrophotometry is the dominant detection method in semiconductor industrial manufacturing and environmental pollution investigation. However, the complex design of the optical structure in existing water quality systems makes these machines bulky and requires large sample volumes, preventing the widespread adoption of lowconcentration solution detection. To address this issue, an optical sensor with a chip-based Micro-Spectrometer was designed for water quality detection in this study, specifically for copper sulfate detection. The developed device can detect concentrations ranging from 2.5% to 0.04%, covering the human lethal dose (500 ppm). Experimental results show that the R² of the detection line is higher than 0.98, and the CV value is less than 5%, indicating that the device is suitable for detecting low concentrations of copper sulfate.