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"Minyak sawit mentah merupakan produk perkebunan terbesar dan menjadi pendulang nilai ekspor bagi Indonesia. Namun, pada produk minyak sawit hasil rafinasi terdapat senyawa kontaminan 3-monochloropropanaediol (3-MCPD) dan apabila dikonsumsi secara berlebih berpotensi menyebabkan penyakit pada ginjal dan testis. Selama ini pengujian kandungan 3-MPCD dilakukan menggunakan alat yang canggih, memerlukan waktu yang lama dan membutuhkan keahlian teknisi yang tinggi. Metode cepat untuk mendeteksi senyawa 3-MCPD masih menjadi tantangan. Penelitian ini bertujuan untuk mengembangkan sensor pendeteksi cepat berbasis kolorimetri menggunakan nanopartikel emas. Sensor nanopartikel emas disintesis dari asam tetrakloroaurat yang direduksi menggunakan senyawa trisodium sitrat. Nanopartikel emas difungsionalisasi oleh capping agent yaitu glutathione (GSH) agar dapat berikatan dengan 3-MCPD. Setiap sampel yang dibuat diuji menggunakan alat berupa UV-Vis spectroscopy UV-Vis, dynamic light scattering (DLS), dan Fourier Transform Infrared (FTIR). Hasil dari penelitian ini didapatkannya komposisi larutan GSH-AuNPs yang stabil. Indikasi deteksi 3-MCPD sangat kuat diwakili oleh turunnya intensitas AnNPs-GSH murni dari 0,8197 menjadi 0,744 ketika dicampurkan 3-MCPD sebanyak 3 ppm. Berdasarkan hal tersebut, dapat disimpulkan GSH-AuNPs berpotensi untuk dikembangkan dalam deteksi 3-MCPD......Crude palm oil is the most extensive product of agriculture in Indonesia and has become a great portion in export value. However, refined palm oil products  contain a harmful substance called 3-monochloropropanaediol (3-MCPD) and if consumed in excess has the potential to cause disease in the kidney and testicle. Detection of 3-MCPD is always dependent on the sophisticated machine, time-consuming and highly skilled technicians. A simple method that proposes rapid detection remains a challenge. Hence, this research  aims to develop a colorimetric-based rapid detection sensor using gold nanoparticles. The sensor material was synthesized from chloroauric acid that was reduced using trisodium citrate to make gold nanoparticle. The gold nanoparticle will be functionalized with a capping agent, glutathione (GSH)  to bind to 3-MCPD. The GSH-AuNPs were tested by UV-Vis spectroscopy (UV-Vis), dynamic light scattering (DLS), and Fourier Transform Infrared (FTIR). The result shows that stable GSH-AuNPs composition has been found. The indication for detection of 3-MCPD is very striking, represented by the decrease in the intensity of pure AuNPs-GSH from 0.8197 to 0.744 when mixed with 3 ppm of 3-MCPD. Based on the results, it can be concluded that GSH-AuNPs have the potential to be developed for the 3-MCPD detector application. "

"Deteksi hidrogen peroksida (H2O2) berhasil dikembangkan dengan metode luminol electrochemiluminescence (ECL) pada permukaan screen-printed carbon electrode (SPCE) yang dimodifikasi dengan partikel emas. ECL luminol diperoleh dari  oksidasi luminol menghasilkan spesies 3-aminoftalat tereksitasi yang kemudian berelaksasi dengan memancarkan intensitas cahaya. H2O2 bertindak sebagai ko-reaktan pada ECL luminol karena hasil oksidasi elektrokimia H2O2 pada permukaan elektroda menghasilkan radikal hidroksil (OH•), yang dapat meningkatkan oksidasi luminol dan akibatnya meningkatkan sinyal ECL luminol. Modifikasi dengan partikel emas di permukaan SPCE dilakukan karena partikel emas memiliki kelebihan yaitu; luas permukaan yang besar, konduktivitas yang sangat baik, dan aktivitas katalitik yang baik terhadap oksidasi H2O2 untuk menghasilkan radikal hidroksil (OH•) yang distabilkan oleh interaksi pertukaran elektron parsial. Teknik voltametri siklik yang digunakan untuk menghasilkan oksidasi H2O2 dan oksidasi luminol yang menghasilkan ECL menunjukkan hubungan linear (R2 = 0,9995) pada rentang konsentrasi H2O2 0,5 µM hingga 200 µM. Sensor yang dikembangkan menunjukkan hasil performa yang baik dengan batas deteksi sebesar 4,78 µM, dan dapat digunakan untuk mendeteksi sampel H2O2 dalam matriks susu dan air keran.......Hydrogen peroxide (H2O2) detection was successfully developed by electrochemiluminescence (ECL) luminol method at a screen-printed carbon electrode modified with gold nanoparticles (AuNPs-SPCE). The ECL detection mechanism follows the oxidation of H2O2 to hydroxyl radicals (OH•) acting as a co-reactant to increase the ECL signal by inducing oxidized luminol to produce an excited species of 3-aminophthalate then relaxes and emits a luminous intensity on the electrode surface. AuNPs was deposited to SPCE due to feature high surface area, excellent conductivity, and good catalytic activity towards H2O2 oxidation to produce hydroxyl radicals (OH•) which stabilized by partial electron exchange interactions. Cyclic voltammetry (CV) technique was used for the ECL measurements which showed liner relationship (R2 = 0.9995) in the range 0.5 to 200 µM of H2O2 concentrations. The developed sensor showed a good perform with an estimated detection limit of 4.78 µM, and applicable for real sample detection of H2O2 in milk and tap water."

"Saat ini, metode pengujian kandungan 3- Monochloropropanediol (3-MCPD) yang merupakan zat kontaminan pada minyak kelapa sawit dilakukan menggunakan instrumen GC-MS. Metode tersebut memerlukan prosedur yang lama dan rumit. Pengembangan nanopartikel emas dengan pengkaping Cysteine berpeluang menjadi solusi untuk mendeteksi 3-MCPD dalam waktu cepat berbasis analisis kolorimetri. Tujuan dari penelitian ini adalah untuk mengetahui kondisi optimal sintesis, ukuran, dan sensitivitas nanopartikel dalam mendeteksi 3-MCPD. Penelitian dilakukan dengan memvariasikan konsentrasi dan volume Cysteine. Variasi konsentrasi Cysteine yang digunakan adalah 0 hingga 0,5 mM, sedangkan variasi volume Cysteine yang dipakai adalah 0 hingga 2 ml. Pengujian 3-MCPD dilakukan dengan variasi konsentrasi 0 hingga 10 ppm. Selanjutnya, karakterisasi dilakukan dengan UV – Vis, FTIR, dan PSA. Sintesis yang optimal didapatkan ketika nanopartikel emas ditambahkan dengan 1 ml 0,025 mM Cysteine menghasilkan warna ruby red yang stabil hingga 24 jam. Ukuran nanopartikel didapatkan 27,1 nm dan terjadi pemutusan ikatan gugus fungsi tiol pada Cys-AuNPs. Nanopartikel emas ini berpotensi untuk dikembangkan lebih lanjut dalam mendeteksi 3-MCPD.......Currently, the assay method of 3-Monochloropropanediol (3-MCPD) which is a contaminant in palm oil is carried out by using the GC-MS instrument. This method requires a long and complicated procedure. The development of gold nanoparticles with cysteine capping has the opportunity to be a solution to detect 3-MCPD in a fast time based on colorimetric analysis. This study aims to determine the optimal conditions for synthesis, size, and sensitivity of nanoparticles in detecting 3-MCPD. The research was conducted by varying the concentration and volume of Cysteine. Cysteine concentration variations used are 0 to 0.5 mM and the volume variation of Cysteine used is 0 to 2 ml. The 3-MCPD test was carried out with a concentration variation of 0 to 10 ppm. Furthermore, characterization was carried out using UV-Vis, FTIR, and PSA. Optimal synthesis was obtained when gold nanoparticles were added with 1 ml of 0.025 mM Cysteine. The color of the nanoparticles is ruby red and stable for up to 24 hours. The nanoparticle size was 27.1 nm, and the thiol functional group bond was broken in Cys-AuNPs. These gold nanoparticles have the potential to be further developed in detecting 3-MCPD."

"ABSTRACTHepatitis B virus (HBV) infects hepatocytes and causes acute and chronic hepatitis that can lead to cirrhosis and hepatocellular carcinoma (HCC) in both animals and humans. Early detection of HBV infection assists in monitoring the patient's response to anti-HBV therapy, blood donation screening, and disease management, control and eradication. This research focused on development of LAMP assay combined with lateral flow dipstick (LFD), gold nanoparticle (AuNPs) and real-time turbidimetry for screening of the hepatitis B virus. Analytical sensitivity, analytical specificity, diagnostic sensitivity, diagnostic specificity, accuracy and predictive value of each technique were determined and compared to conventional PCR and real-time PCR (gold standard method). The analytical sensitivity of LAMP-LFD and LAMP-AuNPs was 1.24x101 copies /mL, LAMP-real-time turbidimetry was 1.24x102 copies/mL, while that of conventional PCR was 1.24x104 copies/mL. Examination of the analytical specificity of all LAMP-based combinations and conventional PCR showed no cross-reactivity with HCV or human plasma. Upon exploration of one hundred unknown samples, in comparison to real-time PCR, the diagnostic sensitivity and specificity of LAMP-based assays were 100% and 90%, respectively. The accuracy, positive predictive value (PPV) and negative predictive value (NPV) of the LAMP-based assays were 98%, 97.56%, and 100%, respectively. While that of conventional PCR were 60%, 100%, 68%, 100% and 38% of diagnostic sensitivity, diagnostic specificity, accuracy, PPV and NPV, respectively. LAMP-based assays need to be simplified in terms of achieving single-step diagnosis using one master mix solution that is suitable for a point-of-care diagnostic test. "