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The increasing circulation of unhealthy foods in various places threatens the community of malnutrition. One of which is the intake of cholesterol nutrition. When the normal limit is exceeded, it can trigger the spread of various diseases such as coronary heart disease. To anticipate the outbreak of the disease, a practical, stable, simple, and relatively inexpensive, non-enzymatic sensor device for monitoring blood cholesterol levels in some food samples such as milk and meat was developed. In this research, nickel modified catalyst on carbon paste electrodes, NiO/CPE by hydrothermal method and Ni/CPE by electrochemical method were developed. A flower-like morphology for NiO was obtained from hydrothermal method and rock-like morphology was obtained from nickel deposit. Results showed that Ni/CPE worked optimally at pH 14 with sensitivity of 0.8148 μA μM−1 cm−2 and limit of detection (LoD) of 0.1645 μM, while NiO/CPE worked optimally at pH 12 with a sensitivity of 0.1238 μA μM−1 cm−2 and LoD of 0.7804 μM. Cholesterol level measurement from the packaged milk sample showed differences of 20.42 % and 47.18 % from the nutrition table information for Ni/CPE and NiO/CPE, respectively.

Measurement of urea concentration in urine is a very important parameter for determining the state of kidney health. With this aim, a non-enzymatic urea sensor comprising Ni metal deposited on an Au electrode has been developed. Ni was first deposited on an Au electrode by varying the potential and time, and then the deposited Ni was activated in KOH to generate NiOOH, which can oxidize urea to CO2, N2 and H2 to allow it to be detected electrochemically. The results show that the Ni/Au electrode can be used to detect urea with a limit of detection (LOD) value of 3.35 × 10−2 mM, a sensitivity of 52.20 mMμA−1cm−2 and a linearity of r2 = 0.997 at a deposition potential of −0.45 V vs. Ag/AgCl after a deposition time of 180 seconds. The Ni/Au electrode has good repeatability and reproducibility (%RSD value) of 0.12% (n = 12) and shows good stability with a %RSD value of 1.60% after 9 days. The Ni/Au electrode performance is not disturbed by the presence of any interfering compounds, such as ascorbic acid, glucose, NaCl, and KCl. The Ni/Au electrode can be used to measure urea levels in urine samples, detecting concentrations of as high as 9.615 mM.

Nitric oxide (NO) plays an important role in physiological processes. NO measurement accuracy is important to understand the essential functions of NO but attaining these levels of accuracy is difficult due to NO’s short half-life. NO concentrations can be determined using an analytical method that has fast response and high sensitivity and is simple and practical. In this study, gold and platinum metals are deposited onto a screen-printed electrode (SPE) surface in a solution mixture of HAuCl4 in 0.05 M H2SO4 and K2PtCl6, in 0.05 M H2SO4, which has been modified with graphene to detect NO. Experiments that varied the deposition concentrations of the Au/Pt onto the G/SPE are conducted to obtain an optimal deposit concentration ratio between AuPt and G/SPE. NO detection tests are conducted at +0.878 V against Ag/AgCl. Deposits of AuPt/G/SPE that have 1:1 concentrations form high-performance sensors due to its high sensitivity at 23029.92 μA mM−1 cm−2, a low detection limit of 2.2 × 10−3 mM, and the best linearity, R2 = 0.9943. No is detected using the Griess Saltzman method. Based on the linearity results from the NO detection measurements, we observe that the electrochemical method provides significant improvements over the Griess Saltzman method.

In this era decentralization, there has been an increasing transfer authority from central government to local government. As a result, some aspects of tourism management have been transferred to local level. This study uses the authority of the Berau local government to illustrate this. Using a descriptive case study with focuses on 7 sub-districts in the Berau Regency, the data were taken by personal observations made through visits and in depth interviews with the regent, head of culture and tourism office and 7 chiefs as the key informants. It was found that the Berau local government give limited authority to the sub-district offices to manage tourism in local areas, however, they do not provide adequate funding for tourism development. They are required to coordinate with the Culture and Tourism Office (CTO) in the Berau Regency. This leads to delays in the development of tourism. This can be seen in public facilities which are not properly maintained, and potential tourist attractions which are not recognized as such, and have not been taken over and maintained by the government. It is suggested that the Berau Local government should transfer authority to the sub-district offices for the sake of efficiency since they posses greater understanding of their areas of responsibility.

Azelaic acid is one of the substances that has anti-acne and skin lightening effects which is often added to cosmetics. In the acne treatment, the azelaic acid is generally used with a concentration of 20% in cream formulation and 15% in gel. The use at concentrations below 10% is not recommended because it does not work effectively. While the use of above 10% is categorized as a medical treatment. In Indonesia, the Head of the National Agency of Drug and Food Control (BPOM) has issued Regulation No. 18 of 2015 on the Technical Requirements of Cosmetics Ingredients Annex V stating that the azelaic acid is banned in cosmetics. However, until this research began the BPOM has not had a valid method to identify it in cosmetics. Consequently, surveillance of such ingredient in products is hard to do. In this research, the fatty acid standard analysis method of AOAC International was modified and validated to be used in the laboratory. The method of analysis involves heating the cream preparations dissolved with methanol and then added BF3-methanol catalyst, followed by extraction and analysis using GCMS. The validation of method shows that the calibration curve is linear with correlative value of 0.9997. The method is fairly sensitive with 0.02% detection limit, and fairly precision with relative standard deviation (RSD) of between 0.626-0.961% and fairly accurate which the recovery percentage is 99.85% at range 98.27-100.72%. In sum the results demonstrate that the method can be used as a routine analysis method for laboratory testing.

Interaction between TiO2 and dyes sensitizer have been studied. The chlorophyll presents in the crude leave extract (CLE-dye) from cassava (Manihot utilissima) was immobilized on to the photo-anode, consists of TiO2 supported by fluor doped Tin oxide (SnO2-F) Glass. The TiO2 was prepared by Rapid Breakdown Anodization (RBA) method then immobilized on to glass coated by SnO2-F using doctor blade technique, to give CLE-dye/TiO2/SnO2-F/Glass photo-anode. The prepared photo-anode was characterized by UV-Vis-DRS, FTIR, XRD, SEM, electrochemical and spectro-electrochemical systems. In this study, the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy level of the CLE-dye were empirically determined by cyclic voltammetry method, while spectro-electro-chemistry method was used to determine the coefficient of degradation and formation of the dyes, and diffusion coefficient of the hole recombination as well. Good anchoring between TiO2 with dye extracts (CLE-dye) can be seen from value of dye LUMO energy level (-4.26 eV), which is approaching the conduction band of TiO2 (-4.3 eV). The coefficient of degradation and formation of the CLE-dye showed a quasi reversible and diffusion coefficient hole recombination values were small, indicated that it is quite suitable as a sensitizer in a dyes sensitized solar cell.