amounts of protein, it negatively impacts kidneys performance because automatic the human body will be reducing the amino acids, which are known as the deaminase process 6,7) . It will produce ammonia compounds from the breakdown of amino acid compounds in the cell, then it will be transferred into the bloodstream and is carried to the liver 8,9) . In the final step, ammonia compounds are excreted in the urea cycle and excreted through the kidneys as urine. Excess amino acids burden the performance of the kidneys and liver because more N atom has to be excreted by the body 10,11) . Therefore, a urine sensor is needed to detect excess amino acids wasted in the human body, which is expected to identify proteinuria diseases. In this research, we study one type of amino acid, namely L-tryp-Abstract: Electrochemical processes are an effective method for detecting dangerous food ingredients. The synergistic between the reduction-oxidation (redox) processes inspired several papers and spurred research towards studying the new materials that can further adapt to optimize the rapid detection of chemical compounds. In this study, we report the eco-synthesis using graphene/TiO 2 rutile (G/TiO 2 ) electrode microstructures easily prepared through the physical method by mixing graphene and TiO 2 powder and its application for sensing L-tryptophan (Trp) compound. The material characterization results show that the graphene surface is smoother than the G/TiO 2 material. Graphene has been detected using X-ray diffraction (XRD) at a value of 2 thetas 26.39° and TiO 2 forms rutile crystals (110). The FTIR spectrum exhibits the functional groups from graphene of -OH, C-H, C=C, C-O, and TiO 2 identified with Ti-O bonds. The electrochemical test against G/TiO 2 electrode microstructures for Trp compound shows that 0.5 g TiO 2 rutile was the best composition functionalized with graphene material under 0.1M K 3 [Fe(CN) 6 ] + 0.1M NaNO 3 electrolyte with a scan rate of 0.1 V/s. Determination of the detection limit was obtained at 0.005 mg/L with a HorRat value of 1.05%. The stability test was carried out for 25 days, and the addition of Pb(NO 3 ) 2 as an interference compound had a significant effect on the decrease in electrode performance.