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"Pada penelitian ini, nanopartikel Cr-doped ZnO dengan kosentrasi Cr yang berbeda (3-16%) telah disintesis dengan metode kopresipitasi. Struktur, sifat optik dan sifat magnetik sampel yang dihasilkan telah dikarakterisasi dengan XRD (Xray Diffraction), EDX (Energy Dispersive X-ray, FTIR (Fourier Transform Infra Red), spektroskopi UV-Vis, ESR (Electron Spin Resonance) dan VSM (Vibrating Sampel Magnetometer). Hasil karakterisasi XRD (X-ray Diffraction) dan EDX (Energy Dispersive X-Ray) menunjukkan bahwa Cr telah bergabung ke dalam ZnO (fase hexagonal wurtzite) tanpa adanya fase kedua. Hasil tersebut menunjukkan bahwa doping Cr menghambat pertumbuhan kristal. Pergeseran merah pada absorbsi band edge pada spektrum absorbansi UV-Vis dengan peningkatan konsentrasi Cr juga mengkonfirmasi doping Cr pada ZnO. FTIR telah dipelajari untuk mengindentifikasi karakteristik frekuensi vibrasi ikatanikatan kimia pada sampel. Hasil ESR menunjukkan penambahan ion Cr 3+ yang mungkin berkontribusi dalam pembentukkan sifat magnet yang diperoleh pada hasil karakterisasi VSM.

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In this research, Cr-doped ZnO nanoparticles with different concentrations of Cr (3-16%) were synthesized by coprecipitation method. The Structure, the optical and the magnetic properties of the produced samples were characterized by XRD (X-ray Diffraction), EDX (Energy Dispersive X-ray, FTIR (Fourier Transform Infra Red), UV-Vis spectroscopy, ESR (Electron Spin Resonance) and VSM (Vibrating Sampel Magnetometer). The XRD (X-ray Diffraction) dan EDX (Energy Dispersive X-Rays) characterization results indicated that Cr has been incorporated into ZnO (hexagonal wurtzite phase) without any secondary phase.

The results indicated that Cr-doping restrained the growth of the crystal. The red shift in band edge absorbtion in UV-Vis absorbance spectrum with in increasing Cr concentration also confirm the doping of Cr in ZnO. FTIR have been studied in order to identify the characteristic frequencies of the vibrational chemical bonds. The ESR results indicated the addition of Cr3+ ions that may contribute in order the magnetic properties that was found in VSM characterization results."

"Nanopartikel oksida seng (ZnO) yang diberi dopan kromium (Cr) dan penambahan 10 % montmorillonite (MMT) disintesis dengan metode kopresipitasi untuk empat variasi persen atom Cr. Nanopartikel dikarakterisasi menggunakan X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), Fourier Transform Infrared (FTIR), UV-Visible Diffuse Reflectance (UV-Vis) dan Electronic Spin Resonance (ESR). Pengujian aktivitas fotokatalitik dilakukan menggunakan model polutan methylene blue dengan paparan sinar UV. Penambahan montmorillonite dan dopan Cr pada ZnO dapat meningkatkan degradasi methylene blue dengan Cr doped ZnO/MMT 10 at.% menunjukkan degradasi maksimum dengan kondisi optimum dosis fotokatalis 0.7 g/L dan konsenstrasi larutan 20 mg/L. Spesies dominan pada aktivitas fotokatalitik adalah hole dan OH● berturut-turut.

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Chromium (Cr) doped zinc oxide (ZnO) nanoparticles with 10% montmorillonite (MMT) addition were synthesized by co-precipitation method for four chrome atomic percentage variations. Samples were characterized by X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), Fourier Transform Infrared (FTIR), UV-Visible Diffuse Reflectance (UV-Vis) and Electronic Spin Resonance (ESR). Photocatalytic were evaluated using methylene blue under UV light irradiation. MMT addition and Cr dopant to ZnO nanoparticles enhance methylene blue degradation with the optimum conditions are 0.7 g/L of nanoparticle and 20 mg/L of methylene blue initial concentration. Hole and OH● were identified as dominant species of photocatalytic activity."

"Zinc Oxide ZnO merupakah salah satu bahan semikonduktor yang banyak diteliti sebagai fotokatalis, namun salah satu kelemahan ZnO adalah rekombinasi yang cepat antara elektron dengan hole yang mengakibatkan efisiensi aktifitas fotokatalitik rendah. Salah satu upaya untuk menekan rekombinasi ini adalah dengan membuat struktur komposit ZnO dengan nanopartikel logam mulia Au dan Ag yang dapat menangkap elektron. Pada penelitian ini dilakukan sintesis nanopartikel AuAg pada nanorod ZnO yang ditumbuhkan di atas kaca dengan metode one-pot hydrothermal. Rasio mol prekursor Au:Ag 1:0 ; 3:1 ; 1:1 ; 1:3 dan 0:1.Hasil FESEM dan TEM menunjukkan bahwa umumnya nanopartikel Au terbentuk dengan diameter 15-30 nm cukup banyak di permukaan nanorod ZnO. Dengan penambahan unsur Ag terlihat jumlah nanopartikel yang terbentuk lebih sedikit dan ukurannya menjadi lebih beragam bahkan terjadi aglomerasi. Nanopartikel AuAg yang terbentuk memiliki struktur kristal fcc dengan bidang dominan 111.

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Zinc Oxide ZnO is one of the most studied semiconductor materials as a photocatalyst, but one of the weaknesses of ZnO is rapid recombination between electrons and holes resulting in low photocatalytic activity efficiency. One attempt to suppress this recombination is to create a ZnO composite structure with noble metal nanoparticles Au and Ag that can capture electrons. In this study, the synthesis of AuAg nanoparticles on ZnO nanorods was grown on glass by one pot hydrothermal method. The mole ratio of Au precursors Ag 1 0 3 1 1 1 1 3 and 0 1.

FESEM and TEM results show that generally Au nanoparticles are formed with a diameter of 15 30 nm in large number on the surface of ZnO nanorods. With the addition of Ag elements it is seen that the number of nanoparticles formed is less and the size becomes more diverse and even the agglomeration occurs. The AuAg nanoparticles formed have an face center cubic crystal structure with a dominant 111 crystal plane."

"Pada penelitian ini, telah berhasil dilakukan sintesis hidrogel nanokomposit NaAlg-PVA-g-AAm termodifikasi nanopartikel ZnO dengan pembentukan ZnO secara in situ di dalam matriks hidrogel dengan metode hidrotermal. Karakteristik hidrogel diamati dengan FTIR, SEM, TEM, EDX, XRD, AAS serta kapasitas swelling-nya. Hidrogel NaAlg-PVA-g-AAm dengan kapasitas swelling terbaik disintesis didapatkan dengan menambahkan PVA dan alginat dengan perbandingan massa sebesar 0,6:3. Hidrogel nanokomposit setelah dimodifikasi dengan ZnO memiliki kapasitas swelling yang lebih tinggi dibandingkan hidrogel yang belum dimodifikasi. Didapatkan hasil untuk hidrogel nanokomposit NaAlg-PVA-g-AAm termodifikasi nanopartikel ZnO yaitu kapasitas swelling maksimumnya 215,5278 g/g, loading ion Zn2 sebesar 285,82 ppm dan kapasitas release 3maksimumnya sebesar 0,9832 ppm. Kinetika swelling hidrogel NaAlg-PVA-g-AAm mengikuti orde pseudo-pertama dengan parameter laju swelling sebesar 350 menit. Sedangkan kinetika swelling hidrogel nanokomposit NaAlg-PVA-g-AAm termodifikasi nanopartikel ZnO mengikuti orde pseudo-kedua dengan parameter laju swelling sebesar 487,5 menit. Dari hasil uji aktivitas antibakteri yang dilakukan secara in-vitro, diketahui S.aureus lebih resisten dibandingakan P. aeruginosa dengan persen inhibisi S. aureus yang lebih besar pada konsentrasi hambat minimum yang sama yaitu 31,25 ppm.

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In this research, NaAlg PVA g AAm nanocomposite hydrogel had been successfully modified by ZnO nanoparticles in the hydrogel matrix by hydrothermal method. Characteristics of hydrogels were observed with FTIR, SEM, TEM, EDX, XRD, AAS and through their swelling capacities. The NaAlg PVA g AAm hydrogel with the best swelling capacity was synthesized by adding PVA and alginate with a mass ratio of 0.6 3. Obtained results for NaAlg PVA g AAm nanocomposite hydrogel modified ZnO nanoparticles had the maximum swelling capacity of 215.52 g g, Zn2 ion loading of 285.82 ppm and its maximum release capacity of 0.98 ppm, while the maximum swelling capacity for a NaAlg PVA g AAm nanocomposite hydrogel was 73.26 g g. Kinetics swelling of NaAlg PVA g AAm hydrogel followed the first pseudo order with a swelling rate parameter of 350 minutes, whereas kinetics swelling of NaAlg PVA g AAm nanocomposite hydrogel modified ZnO nanoparticles followed the second pseudo order with swelling rate parameter of 487.5 minutes. From in vitro antibacterial activity test, S.aureus was known to be more resistant than P. aeruginosa with a greater inhibition percentage of S. aureus at the same minimum inhibitory concentration of 31.25 ppm."

"ZnO nanopartikel dengan berbagai variasi konsentrasi dopan Co2+ (3, 6, 15 dan 17 at.%) disintesis dengan metode ko-presipitasi. Karakerisasi yang dilakukan meliputi pengukuran EDX, XRD dan UV-VIS untuk mengamati struktur dan sifat optis dari ZnO didop Co nanopartikel. Komposisi Co dalam sample dikatahui dari karakterisasi EDX,. Hasil difraksi sinar X (XRD) menunjukkan bahwa sampel memiliki fase wurtzite dan tidak ditemaknnya fase sekunder. Hasil tersebut membuktikan bahwa ion Co2+ telah berhasil mensubtitusi Zn2+ dalam matrix ZnO. Analisis pelebaran puncak sinar X dilakukan untuk menilai crystalline size dan lattice strain dengan menggunakan metode analisis Williamson-Hall (W-H). Seluruh parameter terkait seperti strain, stress dan nilai energy density turut ditentukan nilainya dengan menggunakan berbagai model dari analisis W-H, yakni uniform deformation model (UDM), uniform stress deformation model (USDM) dan uniform deformation energy density model (UDEDM). Ketiga model analisis tersebut akan menghasilkan nilai strain yang berbeda diakibatkan pendekatan-pendekatan yang dilakukan. Sifat optis seperti celah pita energy dikarakterisasi dengan spektroskopi UV-VIS menunjukan penurunan seiring dengan bertambahnya konsentrasi dopan yang diberikan.

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ZnO nanoparticles with different Co2+ doping concentrations (3,6,15 and 17 at.%) were synthesized by co-precipitation method. Characterization technique of EDX, XRD and UV-Visible spectra measurement were done to investigate the effects of the doping concentration on the structural and optical properties of Co doped ZnO nanoparticles (NP). The compositional analysis was carried out by Energy Dispersive X-Ray (EDX) measurement. X-Ray diffraction analysis reveals that the Co doped ZnO NP crystallize in wurzite structure without any impurity phase and Co2+ ion were successfully incorporated into the lattice position of Zn2+ ions in ZnO matrix. The wurzite structure (lattice constant) is decreasing with increasing Co doping concentration, it show their crystallization decrease with the increase of Co2+ doping Concentration. The crystalline development in the Co doped ZnO NP was investigated by X-Ray peak broadening. The Williamson-Hall (WH) analysis was used to study the individual contribution of crystallize size and lattice strain on the peak broadening. All other relevant physical parameter such as strain, stress and energy density values were also calculated using W-H plot analysis with different model, viz, uniform deformation model, uniform stress deformation model and uniform deformation energy density model, the three models yield different strain values, it may be due to anisotropic nature or the material. The optical studies show that the band gap of Co doped ZnO NP decreases with increase doping concentration."

"Nanopartikel ZnO didop Cr disintesis menggunakan metode kopresipitasi untuk empat variasi konsentrasi Cr. Karakteristik nanopartikel dipelajari menggunakan Energy Dispersive X-Ray (EDX), X-Ray Difraction (XRD), Electron Spin Resonance (ESR), Field Emision - Scanning Electron Microscope (FESEM), Fourier Transform-Infrared (FTIR), and spektroskopi Ultra Violet- Visible (UV- Vis). Uji aktivitas nanopartikel diukur melalui degradasi Methyl Orange (MO) dan Methylene Blue (MB) pada daerah sinar Ultraviolet (UV). Hasil menunjukkan keberadaan Cr dan cetyltrimethylammonium bromide (CTAB) dalam sistem ZnO nanopartikel. Nanopartikel yang dihasilkan berfase tunggal dengan struktur heksagonal wurtzite dan mempunyai bentuk spherical-like. Peningkatan konsentrasi dopan Cr dan kehadiran surfaktan kationik CTAB menyebabkan berkurangnya celah energi dan lebih lanjut lagi meningkatkan aktivitas fotokatalitik. Kehadiran surfaktan kationik CTAB menyebabkan nanopartikel ZnO didop Cr lebih efektif dalam mendegradasi zat pewarna anionik MO dibanding kationik MB.

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Cr doped ZnO nanoparticles were synthesized by coprecipitation methods with four variation Cr concentrations. The nanoparticles were characterized by using Energy Dispersive X-Ray (EDX), X-Ray Difraction (XRD), Electron Spin Resonance (ESR), Field Emision - Scanning Electron Microscope (FESEM), Fourier Transform-Infrared (FTIR), and UltraViolet-Visible (UV-Vis) Spectroscopy. The photocatalytic activity of nanoparticles were evaluated by measuring degradation of Methyl Orange (MO) and Methylene Blue (MB) in Ultraviolet (UV) region. The results confirmed the presence of Cr dopant and cationic surfactant cetyltrimethylammonium bromide (CTAB) in the ZnO nanoparticles system. The resulting nanoparticles have single-phases with hexagonal wurzite structures and spherical-like shapes. Increasing the Cr dopant concentrations and the presence of cationic surfactant CTAB cause a reduction in energy gap and more futher improve the photocatalytic activity. The presence of cationic surfactant CTAB causes the Cr doped ZnO nanoparticles were more effective in degrading MO anionic dyes than MB cationic dyes."

"Metode kopresipitasi telah digunakan dalam penelitian ini untuk menghasilkan nanopartikel ZnO didop Mg dari reagent magnesium sulfat heptahidrat, MgSO4.7H2O, dan seng sulfat heptahidrat, ZnSO4.7H2O. Nanopartikel Zn1-xMgxO (x = 0,03, 0,06, 0,10, and 0, 20) dikarakterisasi dengan X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), UV-Visible (UV-Vis) spectroscopy, Fourier Transform Infrared spectroscopy (FTIR), dan Electron Spin Resonance (ESR). Semua sampel mengandung unsur Mg dengan konsentrasi maksimum mencapai 30 at. %, seperti yang ditunjukkan oleh hasil analisis EDX. Fase tunggal ZnO dengan struktur kristal heksagonal (wurtzite) diperoleh untuk semua konsentrasi dopan, yang menunjukkan substitusi Mg ke dalam ZnO.Sampel dalam penelitian ini memiliki rentang ukuran partikel rata-rata 30-40 nm. Nilai-nilai parameter kisi yang dihasilkan tidak berubah secara signifikan dibandingkan dengan ZnO tanpa dopan. Spektrum serapan inframerah juga menegaskan substitusi Mg dengan mode vibrasi di sekitar bilangan gelombang 908 cm-1 dan 1388 cm-1. Semua sampel menunjukkan nilai reflektansi yang relatif besar pada panjang gelombang 400-800 nm, sedangkan nilai reflektansi yang kecil dalam rentang panjang gelombang 200-350 nm. Peningkatan celah pita energi dengan meningkatnya konsentrasi Mg dikaitkan dengan perubahan level energi dalam pita konduksi dan valensi pada ZnO (Burstein-Moss efek). Nilai g-value mengindikasikan keberadaan Mg dalam struktur wurtzite ZnO dan perubahan intensitas sinyal ESR juga dapat mengkonfirmasi keberadaan Mg dalam struktur wurtzite ZnO.

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Coprecipitation method has been used in this study to produce Mg-doped ZnO nanoparticles of magnesium sulfate heptahydrate, MgSO4.7H2O, and zinc sulfate heptahydrate, ZnSO4.7H2O. The synthesized Zn1-xMgxO-NPs were characterized by X-ray diffraction (XRD) analysis, energy dispersive x-ray (EDX) spectroscopy, UV-Visible spectroscopy, infrared absorption spectroscopy (FTIR) and electron spin resonance (ESR). All samples contained elements of Mg with a maximum concentration reaches 30 at. %, as demonstrated by the results of EDX analysis. Single phase ZnO with hexagonal crystal structure (wurtzite) are obtained for all the dopant concentration, which suggested the substitution of Mg into ZnO.

The sample in this study had an average particle size ranging in 30-40 nm. The resulting lattice parameter values did not change significantly with respect to Mg dopant concentration. Infrared absorption spectra also confirmed the substitution of Mg with vibrational modes around wave number of 908 cm-1 and 1388 cm-1. All samples showed a relatively large value of reflectance at a wavelength of 400-800 nm (visible region), whereas a small value of the reflectance in the wavelength range 200-350 nm (UV region). Enhancement of energy band gap with increasing concentration of Mg is associated with changes in energy levels in the conduction band and valence band on ZnO (Burstein-Moss effect). ESR spectra yield g values indicating the presence of Mg in the ZnO wurtzite structure and changes in the intensity of the ESR signal can also confirm the presence of Mg in the ZnO wurtzite structure."

"Pada proses sintesis nanopartikel ZnO, diperlukan surfaktan yang digunakan untuk mengontrol ukuran dan dispersi nanopartikel. Daun sengon memiliki kandungan saponin yang berperan sebagai biosurfaktan dan dapat berperan sebagai alternatif dari surfaktan yang umum digunakan yang bersifat toksik dan non-biodegradable. Pada penelitian ini, daun sengon (Albizia Chinensis) diekstrak menggunakan metode maserasi untuk menghasilkan maserat kental. Saponin pada ekstrak daun sengon dapat digunakan sebagai agen capping pada proses biosintesis nanopartikel ZnO. Nanopartikel ZnO kemudian digunakan dalam formulasi tabir surya untuk meningkatkan kemampuan antibakteri. Proses pembentukkan ZnO pada sintesis berlangsung terjadi melalui mekanisme reaksi antara larutan prekursor Zn(CH3COO)2.2H2O dengan ekstrak saponin dari daun sengon dan NaOH. Biosintesis nanopartikel ZnO dilakukan menggunakan ekstrak daun sengon dan pengujian kristal ZnO dilakukan. Formulasi tabir surya dilakukan dan pengujian antibakteri dilakukan dengan mengukur zona hambat bakteri E. Coli. ZnO yang disintesis memiliki struktur kristal heksagonal wurtzite dengan ukuran partikel terkecil 405 nm dan kemurnian 75%. Tabir surya yang dihasilkan menggunakan ZnO hasil sintesis memiliki performa Sun Protection Factor (SPF) dan antibakteri yang serupa dengan ZnO komersial dengan nilai SPF tertinggi 32 dan diameter daerah hambat 10,2 cm.

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In the process of synthesizing ZnO nanoparticles, surfactants are needed to control the size and dispersion of nanoparticles. Sengon leaves contain saponins that act as biosurfactants and can act as an alternative to commonly used surfactants that are toxic and non-biodegradable. In this study, the leaves of sengon (Albizia Chinensis) were extracted using maceration. Saponins in the extract can be used as capping agents in the ZnO nanoparticle biosynthesis process. The ZnO nanoparticles were then used in sunscreen formulations to enhance the antibacterial ability. The process of forming ZnO in the synthesis takes place through a reaction mechanism between the precursor solution of Zn(CH3COO)2.2H2O with saponin from sengon leaves and NaOH. The biosynthesis of ZnO nanoparticles was carried out using sengon leaf extract and ZnO crystal analysis was carried out. Sunscreen formulations were carried out and antibacterial testing was carried out by measuring the inhibition zone of E. Coli. The synthesized ZnO has a hexagonal wurtzite crystal structure with the particle size of 405 nm and 75% purity. The sunscreen produced using synthesized ZnO has Sun Protection Factor (SPF) and antibacterial performance similar to commercial ZnO with the highest SPF value of 32 and the diameter of the inhibition zone is 10.2 cm."

"ZnO nanoparticles were successfully synthesized by a solochemical method using zinc chloride as the precursor in a sodium hydroxide solution with ZnCl2:NaOH ratios of 1:2 and 1:3. The effects of the thermal treatment on the functionalities of the nanoparticles were investigated by comparing calcined ZnO with uncalcined ZnO. Calcined ZnO underwent a drying process at 120°C, followed by calcination at 500°C, while uncalcined ZnO underwent the drying process only. The synthesized nanoparticles were characterized by XRD and FESEM-EDX analysis. The photoactivity of synthesized ZnO was evaluated through methylene blue degradation. In addition, ZnO nanofluids were synthesized by dispersing nanoparticles into the base fluid. The nanofluidic stability in the presence of a Palm Oil-Based Primary Alkyl Sulphate (palmPAS) surfactant were investigated using a spectrophotometer UV-vis with varied PalmPAS concentrations. XRD and FESEM analysis showed that the nanoparticles exhibited a hexagonal wurtzite structure, and confirmed that the particle size increased on calcination. All the synthesized ZnO nanoparticles exhibited good photoactivity under UV light irradiation due, to some extent, to their good crystallinity. The calcined ZnO from the ZnCl2:NaOH ratio of 1:3 offered the best photocatalytic performance compared to its ZnO counterparts. It was also found that the nanofluids of uncalcined ZnO from the ZnCl2:NaOH ratio of 1:3, at a ZnO:palmPAS ratio of 1:9, offered the best stability."

"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.

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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."