Liquefied Petroleum Gas (LPG) is a gas commonly used in industry and daily consumption. Therefore, the detection of LPG on Earth is very important. LPG detection can be carried out using r-GO-TiO2 semiconductors, which are effective resistive sensors for detecting chemical interactions at low electronvolt (eV) energies. This research aims to synthesize r-GO-TiO2 through the humming method, confirm the success of the synthesis using FTIR, produce r-GO-TiO2 semiconductors, assess the fabrication success using Tauc plot and Hall effect methods, and evaluate the quality of experimental data with linear regression, Pearson correlation, and the coefficient of determination. Furthermore, this study will design and construct a sensor reactor for LPG detection, measure resistivity and response time as detection indicators, and explain how LPG can be detected based on the resistivity of the r-GO-TiO2 semiconductor. The methods used include graphene oxidation with KMnO4 and H2SO4, Tauc plot to measure the band-gap, Hall effect tests to determine the relationship between mobility and charge carrier type, as well as linear regression and Pearson correlation analysis to evaluate data quality. Additionally, resistivity and response time measurements are conducted to test the quality of LPG detection. The synthesis reaction of r-GO was successfully demonstrated by FTIR results. In r-GO, -OH groups, C=C bonds in sp², electron excitation in the graphene layer, residual C=O groups, -OH, and C–O after the oxidation process were observed, with a band gap of 2.16 eV. The relationship of electrical sensitivity between the semiconductors shows a Pearson correlation of r = 0.934 and a coefficient of determination R² = 0.785, indicating a very good relationship. In conclusion, the synthesis process using the humming method and the fabrication of r-GO-TiO2 semiconductors were successful, and the performance of the semiconductor sensor for LPG detection was also very good.