Electrogenerated Chemiluminescence on Smartphone with Graphene Quantum Dots Nanocomposites for Escherichia Coli Detection

•Graphene quantum dots nanocomposites were applied to amplify and stabilize the luminescence signals.•Functional modules on smartphone for voltage excitation and luminescence capture.•Luminescence images were processed by a smartphone-based image analysis application.•Escherichia Coli detection on smartphone for point-of-care testing.