Fig. 3From: Detection of pH and Enzyme-Free H2O2 Sensing Mechanism by Using GdO x Membrane in Electrolyte-Insulator-Semiconductor StructureXPS characteristics of Si2p for a S1, b S2, and c S3 samples. Corresponding O1s spectra of d S1, e S2, and f S3 samples are shown. The S3 film shows higher Gd/Gd2O3 ratio or oxygen deficient and higher OH group which helps to sense H2O2 Back to article page