The comparison between light-scattering detectors based on LED and photodiode for immunoprecipitation assays of transferrin and ferritin - ScienceDirect
LED Light Sensors
Better LED As Light Sensor : 4 Steps (with Pictures) - Instructables
Simple LDR Circuit to Detect Light
Light Detector using LDR - ElectronicsHub
IR Sensor | Basics, Types, Circuit, Working, Projects, FAQs