J. Gunlazuardi, A. Fisli, Ridwan., Y. Krisnandi, D. Robert
A photocatalyst supported on magnetic material allows the simple technique by using an external magnetic material to separate photocatalyst from the treated water. Thus, it is a magnetically separable nanoparticles photocatalyst (MSNP). The use of superparamagnetic nanoparticles that do not pose spontaneous magnetic moment thus could be dispersed in water and can be recollected easily by an external magnetic bar. We prepare Fe3O4/SiO2/TiO2 composite by hetero agglomeration of Fe3O4/SiO2 and TiO2 at a pH range of 3 to 6.2 in an aqueous slurry. The Fe3O4/SiO2 was prepared via coprecipitation of iron (II) and iron (III) ionic solution containing ammonium hydroxide and sodium silicate. The prepared composites were characterized by XRD, TEM, FTIR, and VSM, while the photocatalytic activities were tested toward paraquat in water. Based on zeta potential values, the Fe3O4/SiO2 and TiO2 were being hetero agglomerated at pH 5 to obtain Fe3O4/SiO2/TiO2 composite. The XRD characterization confirmed the presence of anatase, rutile, and magnetite crystal phases. TEM images showed that the Fe3O4 was covered by SiO2 and randomly attached to TiO2. The observed FTIR peak at 940-960 cm attributed to -Si-O-Tibonding mode, ensuring photocatalyst (TiO2) adherence to the Fe3O4/SiO2 cluster. The prepared Fe3O4/SiO2/TiO2 composite showed good photocatalytic activity for the paraquat removal and showed a good magnetic property (VSM measurement).
磁性材料支撑的光催化剂允许使用外部磁性材料将光催化剂与处理过的水分离的简单技术。因此，它是一种磁性可分离的纳米颗粒光催化剂。超顺磁性纳米颗粒的使用不会产生自发磁矩，因此可以分散在水中，并且可以通过外部磁棒轻松地回收。将Fe3O4/SiO2与TiO2在pH为3 ~ 6.2的水浆中异质团聚制备Fe3O4/SiO2/TiO2复合材料。采用含氢氧化铵和硅酸钠的铁(II)和铁(III)离子溶液共沉淀法制备了Fe3O4/SiO2。采用XRD、TEM、FTIR、VSM对复合材料进行了表征，并对水中百草枯的光催化活性进行了测试。根据zeta电位值，将Fe3O4/SiO2与TiO2在pH为5的条件下异质团聚，得到Fe3O4/SiO2/TiO2复合材料。XRD表征证实了锐钛矿、金红石和磁铁矿的存在。TEM图像显示，Fe3O4被SiO2覆盖，并随机附着在TiO2上。在940-960 cm处观察到的FTIR峰归因于- si - o - ti键合模式，确保光催化剂(TiO2)粘附在Fe3O4/SiO2簇上。制备的Fe3O4/SiO2/TiO2复合材料对百草枯的去除具有良好的光催化活性，并具有良好的磁性能(VSM测量)。
{"title":"Magnetically Separable Fe3O4/SiO2/TiO2 Photocatalyst Composites Prepared through Hetero Agglomeration for the Photocatalytic Degradation of Paraquat","authors":"J. Gunlazuardi, A. Fisli, Ridwan., Y. Krisnandi, D. Robert","doi":"10.7454/mss.v25i4.1277","DOIUrl":"https://doi.org/10.7454/mss.v25i4.1277","url":null,"abstract":"A photocatalyst supported on magnetic material allows the simple technique by using an external magnetic material to separate photocatalyst from the treated water. Thus, it is a magnetically separable nanoparticles photocatalyst (MSNP). The use of superparamagnetic nanoparticles that do not pose spontaneous magnetic moment thus could be dispersed in water and can be recollected easily by an external magnetic bar. We prepare Fe3O4/SiO2/TiO2 composite by hetero agglomeration of Fe3O4/SiO2 and TiO2 at a pH range of 3 to 6.2 in an aqueous slurry. The Fe3O4/SiO2 was prepared via coprecipitation of iron (II) and iron (III) ionic solution containing ammonium hydroxide and sodium silicate. The prepared composites were characterized by XRD, TEM, FTIR, and VSM, while the photocatalytic activities were tested toward paraquat in water. Based on zeta potential values, the Fe3O4/SiO2 and TiO2 were being hetero agglomerated at pH 5 to obtain Fe3O4/SiO2/TiO2 composite. The XRD characterization confirmed the presence of anatase, rutile, and magnetite crystal phases. TEM images showed that the Fe3O4 was covered by SiO2 and randomly attached to TiO2. The observed FTIR peak at 940-960 cm attributed to -Si-O-Tibonding mode, ensuring photocatalyst (TiO2) adherence to the Fe3O4/SiO2 cluster. The prepared Fe3O4/SiO2/TiO2 composite showed good photocatalytic activity for the paraquat removal and showed a good magnetic property (VSM measurement).","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"18 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90071548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Yusoff, A. Mahyuddin, Z. Hassan, Muhammad, Syariffudin Yahya
We proposed a technique for improving the platinum (Pt) Schottky contact dark current of the AlN/GaN/AlN/Si(111) substrate. The AlN/GaN/AlN/ heterostructure sample was successfully grown on a silicon substrate by radio frequency molecular beam epitaxy. The high quality of the interlayer heterostructure sample was verified by transmission electron microscopy (TEM). From the TEM image, a good quality single interface layer with spacing less than 1 nm was detected. The strong significant peaks obtained by X-ray diffraction measurement indicated that the sample has a high structural quality for each grown layer. Dry oxidation and thermal annealing were used in conjunction to effectively reduce the leakage current of the Schottky contact of the AlN/GaN/AlN/Si(111) substrate. Energy-dispersive X-ray analysis revealed the presence of the element oxygen. Dry oxidation enhanced the surface roughness and surface-active area of the samples. Al2O3 contributed to the low leakage current of the Pt Schottky contact of the AlN/GaN/AlN/Si(111) substrate. The Al2O3 layer acted as an insulator layer, and retarded the current flow of devices.
{"title":"Effect of Dry Oxidation and Thermal Annealing on AlN/GaN/AlN/Si (111) and Evaluation of its Electrical Characteristics","authors":"M. Yusoff, A. Mahyuddin, Z. Hassan, Muhammad, Syariffudin Yahya","doi":"10.7454/mss.v25i4.1249","DOIUrl":"https://doi.org/10.7454/mss.v25i4.1249","url":null,"abstract":"We proposed a technique for improving the platinum (Pt) Schottky contact dark current of the AlN/GaN/AlN/Si(111) substrate. The AlN/GaN/AlN/ heterostructure sample was successfully grown on a silicon substrate by radio frequency molecular beam epitaxy. The high quality of the interlayer heterostructure sample was verified by transmission electron microscopy (TEM). From the TEM image, a good quality single interface layer with spacing less than 1 nm was detected. The strong significant peaks obtained by X-ray diffraction measurement indicated that the sample has a high structural quality for each grown layer. Dry oxidation and thermal annealing were used in conjunction to effectively reduce the leakage current of the Schottky contact of the AlN/GaN/AlN/Si(111) substrate. Energy-dispersive X-ray analysis revealed the presence of the element oxygen. Dry oxidation enhanced the surface roughness and surface-active area of the samples. Al2O3 contributed to the low leakage current of the Pt Schottky contact of the AlN/GaN/AlN/Si(111) substrate. The Al2O3 layer acted as an insulator layer, and retarded the current flow of devices.","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"92 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73006317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Fauzi, M. Y. Hidayat, Bambang Hindratmo, S. Masitoh, G. S. Saragih
Long-term lead (Pb) exposure can affect human health. Used battery recycling is a source of Pb emission, and the smoke from the facility carries Pb particles that accumulate in the soil. This study aimed to determine the concentration of accumulated Pb in the soil around Kadu Manis Battery Recycling Industrial Estate, Tangerang Regency, Banten Province, Indonesia in 2018. Soil samples were collected by employing a purposive strategy in four directions from the hot spot at a 0–7.5 km radius. Pb content in the soil was analyzed using a modified version of the official method from American Public Health Association number 3030-H in 2012 and work instructions for metal 01 in 2014. Results showed that the Pb concentration in the soil around this site was below the threshold with an average value of 94.43 mg/kg dry weight and a range of 16.56–279.42 mg/kg dry weight. The soil closest to the facility had the highest Pb concentration. These findings indicated that the management of emission from used battery recycling site must be improved.
{"title":"Lead Concentration in The Soil Around a Used Battery Recycling Site in Tangerang Regency, Indonesia","authors":"R. Fauzi, M. Y. Hidayat, Bambang Hindratmo, S. Masitoh, G. S. Saragih","doi":"10.7454/mss.v25i4.1281","DOIUrl":"https://doi.org/10.7454/mss.v25i4.1281","url":null,"abstract":"Long-term lead (Pb) exposure can affect human health. Used battery recycling is a source of Pb emission, and the smoke from the facility carries Pb particles that accumulate in the soil. This study aimed to determine the concentration of accumulated Pb in the soil around Kadu Manis Battery Recycling Industrial Estate, Tangerang Regency, Banten Province, Indonesia in 2018. Soil samples were collected by employing a purposive strategy in four directions from the hot spot at a 0–7.5 km radius. Pb content in the soil was analyzed using a modified version of the official method from American Public Health Association number 3030-H in 2012 and work instructions for metal 01 in 2014. Results showed that the Pb concentration in the soil around this site was below the threshold with an average value of 94.43 mg/kg dry weight and a range of 16.56–279.42 mg/kg dry weight. The soil closest to the facility had the highest Pb concentration. These findings indicated that the management of emission from used battery recycling site must be improved.","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"15 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84400189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gabriella Chandrakirana Krisnamurti, Dewi Ratih Tirto Sari, Y. Bare
The number of tuberculosis (TB) cases worldwide reached 1.5 million in 2018; thus, TB is considered a deadly disease. TB is caused by Mycobacterium tuberculosis and involves lipid synthesis. Considering the importance of lipid metabolism in bacteria, FabH may be an essential protein target for repressing lipid synthesis. Capsaicinoids from Capsicum annuum demonstrate potent antibacterial activity. This study predicted the ability of capsaicinoid compounds to inhibit FabH. In silico analysis was performed by retrieving the structure of FabH from PDB and those of selected capsaicinoid derivatives from PubChem. The compounds were docked using AutoDock Vina in PyRx 0.8 software. The interactions of FabH and different capsaicinoid derivatives showed identical binding characteristics. The bonding type most frequently observed was hydrogen bonds. In conclusion, capsaicinoid derivatives could block lipid synthesis through FabH. The relevant mechanism and biological processes should be studied further.
{"title":"Capsaicinoids from Capsicum annuum as an Alternative FabH Inhibitor of Mycobacterium Tuberculosis: In Silico Study","authors":"Gabriella Chandrakirana Krisnamurti, Dewi Ratih Tirto Sari, Y. Bare","doi":"10.7454/mss.v25i4.1248","DOIUrl":"https://doi.org/10.7454/mss.v25i4.1248","url":null,"abstract":"The number of tuberculosis (TB) cases worldwide reached 1.5 million in 2018; thus, TB is considered a deadly disease. TB is caused by Mycobacterium tuberculosis and involves lipid synthesis. Considering the importance of lipid metabolism in bacteria, FabH may be an essential protein target for repressing lipid synthesis. Capsaicinoids from Capsicum annuum demonstrate potent antibacterial activity. This study predicted the ability of capsaicinoid compounds to inhibit FabH. In silico analysis was performed by retrieving the structure of FabH from PDB and those of selected capsaicinoid derivatives from PubChem. The compounds were docked using AutoDock Vina in PyRx 0.8 software. The interactions of FabH and different capsaicinoid derivatives showed identical binding characteristics. The bonding type most frequently observed was hydrogen bonds. In conclusion, capsaicinoid derivatives could block lipid synthesis through FabH. The relevant mechanism and biological processes should be studied further.","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87131956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tin mining was the predominate mining industry in Malaysia, especially during the mid-19th century. Most of the former mining areas have been reused for aquaculture purposes. Fish produced from former mining areas have been misunderstood as a high health risk if consumed due to their likelihood of containing high heavy metal content in their tissue. Therefore, we review national information on trace metals levels in the fish tissue of the selected former mining ponds in Peninsular Malaysia, together with background content of trace metals in their surroundings and food security and human health implications. Seven trace metals (Cu, Zn, As, Cd, Pb, Cr, and Ni) were observed in the water column and sediment. Various reports showed that background trace metal concentrations in the former mining area are mostly lower than several established limits (which were used as the main reference), except for the areas that were being treated for secondary use. Trace metal contents in the fish tissue also showed the same tendency of high contents due to improper or unfinished treatment of former mining ponds. In the context of food safety, various local reports have shown that the consumption of aquaculture products from former mining areas over a lifetime is unlikely causing any hazardous impact and hence may be regarded to be safe. However, these findings are restricted due to the limited studies in Peninsular Malaysia. Therefore, extensive study regarding this particular issue is highly recommended.
{"title":"Bioaccumulation of Trace Metals for Daily Fish Consumption from Selected Former Tin Mining Ponds in Peninsular Malaysia: A Review on Safety of Fish Consumption","authors":"M. H. Rosli, A. Joni, Nur Khaliesah Abdul Malik","doi":"10.7454/mss.v25i4.1282","DOIUrl":"https://doi.org/10.7454/mss.v25i4.1282","url":null,"abstract":"Tin mining was the predominate mining industry in Malaysia, especially during the mid-19th century. Most of the former mining areas have been reused for aquaculture purposes. Fish produced from former mining areas have been misunderstood as a high health risk if consumed due to their likelihood of containing high heavy metal content in their tissue. Therefore, we review national information on trace metals levels in the fish tissue of the selected former mining ponds in Peninsular Malaysia, together with background content of trace metals in their surroundings and food security and human health implications. Seven trace metals (Cu, Zn, As, Cd, Pb, Cr, and Ni) were observed in the water column and sediment. Various reports showed that background trace metal concentrations in the former mining area are mostly lower than several established limits (which were used as the main reference), except for the areas that were being treated for secondary use. Trace metal contents in the fish tissue also showed the same tendency of high contents due to improper or unfinished treatment of former mining ponds. In the context of food safety, various local reports have shown that the consumption of aquaculture products from former mining areas over a lifetime is unlikely causing any hazardous impact and hence may be regarded to be safe. However, these findings are restricted due to the limited studies in Peninsular Malaysia. Therefore, extensive study regarding this particular issue is highly recommended.","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"19 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73120390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. S. Saragih, Ely Rahmi Tapriziah, Y. Syofyan, S. Masitoh, Y. S. H. Pandiangan
Artisanal and small-scale gold mining (ASGM) activities often pollute soil, water, and air, thereby achieving widespread proliferation, and contaminating the surrounding biota including plants. Mercury contamination on agricultural land around ASGM areas has been widely reported. This study aims to determine the total mercury contamination in plants and soil around active ASGM sites in Sukabumi Regency, Indonesia, namely, Waluran, Lengkong, and Ciemas Districts. Total mercury (Hg) content was measured from 27 plant samples (including cassava [Manihot utilisima], rice [Oryza sativa], and papaya [Carica papaya]), 7 rhizosphere soil samples, and 7 non-rhizosphere soil samples. Data were analyzed using Kruskal–Wallis test. Results showed no significant difference in total mercury concentrations among locations or plant parts, between rhizosphere and non-rhizosphere soils (p > 0.05), and among cassava plant parts, papaya, and rice. The highest mercury level was found in cassava (0.33–43.27 ppm). Mercury contamination in rice and papaya was relatively low at 0.03– 1.22 and 0.06–5.11 ppm, respectively. According to the Regulation of the Head of BPOM of the Republic of Indonesia Number 23 of 2017 concerning the Maximum Limit of Heavy Metal Contamination in Processed Food, 0.03 ppm is the maximum limit of mercury contamination in fruits, vegetables, and cereals. Therefore, all plant samples around the ASGM sites have exceeded the maximum mercury contamination and thus are not suitable for consumption.
{"title":"Mercury Contamination in Selected Edible Plants and Soil from Artisanal and Small-scale Gold Mining in Sukabumi Regency, Indonesia","authors":"G. S. Saragih, Ely Rahmi Tapriziah, Y. Syofyan, S. Masitoh, Y. S. H. Pandiangan","doi":"10.7454/mss.v25i4.1280","DOIUrl":"https://doi.org/10.7454/mss.v25i4.1280","url":null,"abstract":"Artisanal and small-scale gold mining (ASGM) activities often pollute soil, water, and air, thereby achieving widespread proliferation, and contaminating the surrounding biota including plants. Mercury contamination on agricultural land around ASGM areas has been widely reported. This study aims to determine the total mercury contamination in plants and soil around active ASGM sites in Sukabumi Regency, Indonesia, namely, Waluran, Lengkong, and Ciemas Districts. Total mercury (Hg) content was measured from 27 plant samples (including cassava [Manihot utilisima], rice [Oryza sativa], and papaya [Carica papaya]), 7 rhizosphere soil samples, and 7 non-rhizosphere soil samples. Data were analyzed using Kruskal–Wallis test. Results showed no significant difference in total mercury concentrations among locations or plant parts, between rhizosphere and non-rhizosphere soils (p > 0.05), and among cassava plant parts, papaya, and rice. The highest mercury level was found in cassava (0.33–43.27 ppm). Mercury contamination in rice and papaya was relatively low at 0.03– 1.22 and 0.06–5.11 ppm, respectively. According to the Regulation of the Head of BPOM of the Republic of Indonesia Number 23 of 2017 concerning the Maximum Limit of Heavy Metal Contamination in Processed Food, 0.03 ppm is the maximum limit of mercury contamination in fruits, vegetables, and cereals. Therefore, all plant samples around the ASGM sites have exceeded the maximum mercury contamination and thus are not suitable for consumption.","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"19 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87044280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Wijayanti, A. Safitri, D. Siswanto, Lidwina Faraline Triprisila, F. Fatchiyah
Purple rice is a potential source of ferulic acid, which has antimicrobial properties. However, the inhibitory mechanism of ferulic acid on the growth of bacteria, particularly Salmonella and Listeria, has not been elucidated. This study aimed to determine the bioactivity of ferulic acid from purple rice as an antimicrobial agent against Salmonella typhimurium and Listeria monocytogenes using in vitro and in silico analyses. The antimicrobial activity of a purple rice ferulic acid extract was tested using the agar well diffusion method. Its effect on bacterial cells was observed using scanning electron microscopy. Ferulic acid was confirmed to have antimicrobial properties using in silico software to attenuate the binding of bacterial virulence factors (lipoproteins, lipopolysaccharides, and flagellins) to Toll-like receptors (TLRs) and to prevent interactions with peptidoglycans. The purple rice ferulic acid extract inhibited bacterial growth. The inhibitory effects included induction of a biofilm and shrinkage of S. Typhimurium, as well as osmotic lysis of L. monocytogenes. This activity was supported by the ability of ferulic acid to inhibit the binding of bacterial virulence factors with TLRs and block bacterial peptidoglycans. These findings indicate that the purple rice ferulic acid extract acts as antimicrobial, both directly to bacterial cells and indirectly through TLRs. We conclude that ferulic acid from Indonesian purple rice has a biological function as an antimicrobial agent.
{"title":"Antimicrobial Activity of Ferulic Acid in Indonesian Purple Rice through Toll-like Receptor Signaling","authors":"E. Wijayanti, A. Safitri, D. Siswanto, Lidwina Faraline Triprisila, F. Fatchiyah","doi":"10.7454/mss.v25i4.1266","DOIUrl":"https://doi.org/10.7454/mss.v25i4.1266","url":null,"abstract":"Purple rice is a potential source of ferulic acid, which has antimicrobial properties. However, the inhibitory mechanism of ferulic acid on the growth of bacteria, particularly Salmonella and Listeria, has not been elucidated. This study aimed to determine the bioactivity of ferulic acid from purple rice as an antimicrobial agent against Salmonella typhimurium and Listeria monocytogenes using in vitro and in silico analyses. The antimicrobial activity of a purple rice ferulic acid extract was tested using the agar well diffusion method. Its effect on bacterial cells was observed using scanning electron microscopy. Ferulic acid was confirmed to have antimicrobial properties using in silico software to attenuate the binding of bacterial virulence factors (lipoproteins, lipopolysaccharides, and flagellins) to Toll-like receptors (TLRs) and to prevent interactions with peptidoglycans. The purple rice ferulic acid extract inhibited bacterial growth. The inhibitory effects included induction of a biofilm and shrinkage of S. Typhimurium, as well as osmotic lysis of L. monocytogenes. This activity was supported by the ability of ferulic acid to inhibit the binding of bacterial virulence factors with TLRs and block bacterial peptidoglycans. These findings indicate that the purple rice ferulic acid extract acts as antimicrobial, both directly to bacterial cells and indirectly through TLRs. We conclude that ferulic acid from Indonesian purple rice has a biological function as an antimicrobial agent.","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"114 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79222665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Solikhin, Y. Hadi, M. Y. Massijaya, S. Nikmatin
In this study, the effect of different extraction solvents on the isolation and properties of cellulosic nanofibers (CNFs) were investigated. The unextracted and different solvent-extracted CNFs formed horn-like features and irregularly aggregated nanofibers after oven drying. Scanning electron microscopy at 10000× magnification revealed the smooth external surfaces of all extracted CNFs; this finding is attributed to the limited deposition of amorphous lignocellulosic components on the fibers. All resultant CNF solutions revealed aggregation, with a particle size distribution and zeta average of 21.39–513.00 nm and 162.26–342.13 nm, respectively. Extraction with different solvents and chemical treatment yielded CNF solutions with good transparency. Increases in crystallinity indices were generated by extractive removal and enhanced the delignification and bleaching processes. The atomic crystal size of untreated and different solvent-treated CNFs varied with the type of native cellulose. A dramatic decrease in organic (i.e., C, N, and O) and inorganic (i.e., Na, K, and Si) elements was observed following extractive removal and cellulose purification.
{"title":"Effects of Different Extraction Solvents on the Extractive Removal and Properties of Oil Palm Empty-Fruit Bunch Cellulosic Nanofibers","authors":"A. Solikhin, Y. Hadi, M. Y. Massijaya, S. Nikmatin","doi":"10.7454/mss.v25i3.1236","DOIUrl":"https://doi.org/10.7454/mss.v25i3.1236","url":null,"abstract":"In this study, the effect of different extraction solvents on the isolation and properties of cellulosic nanofibers (CNFs) were investigated. The unextracted and different solvent-extracted CNFs formed horn-like features and irregularly aggregated nanofibers after oven drying. Scanning electron microscopy at 10000× magnification revealed the smooth external surfaces of all extracted CNFs; this finding is attributed to the limited deposition of amorphous lignocellulosic components on the fibers. All resultant CNF solutions revealed aggregation, with a particle size distribution and zeta average of 21.39–513.00 nm and 162.26–342.13 nm, respectively. Extraction with different solvents and chemical treatment yielded CNF solutions with good transparency. Increases in crystallinity indices were generated by extractive removal and enhanced the delignification and bleaching processes. The atomic crystal size of untreated and different solvent-treated CNFs varied with the type of native cellulose. A dramatic decrease in organic (i.e., C, N, and O) and inorganic (i.e., Na, K, and Si) elements was observed following extractive removal and cellulose purification.","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"10 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88873750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Saepudin, T. Yuliani, M. A. F. Nasution, M. Khalil, J. Hong, T. Ivandini
In this study, electrochemical detection of acrylamide using hemoglobin (Hb)-modified core–shell Fe3O4@Au nanostructures was conducted. Fe3O4 nanoparticles (~4.9 nm) and core–shell Fe3O4@Au (5.0–6.4 nm) nanostructures were successfully synthesized by the thermal decomposition method. Electrochemical investigation revealed that the optimum amount of Hb of 2 mg/mL could be immobilized in 0.1 M acetate buffer solution (pH = 6). Moreover, the detection of acrylamide using Fe3O4@Au/Hb was evaluated by the cyclic voltammetry technique. A linear calibration curve (R = 0.98) in the concentration range of 0.1 to 1.0 μM could be achieved with an estimated limit of detection, limit of quantification, and sensitivity of 0.136 μM, 0.453 μM, and 0.4411 μA/μM, respectively. Furthermore, the developed biosensor exhibited high selectivity in the presence of ascorbic acid, melamine, and caffeine. The developed biosensor was applied to the detection of acrylamide in coffee samples and validated using the standard high-performance liquid chromatography (HPLC) method. The concentration of acrylamide in coffee samples was determined to be 37.450 and 35.377 ppm using electrochemical measurement and HPLC, respectively.
{"title":"Hemoglobin-Modified Core–Shell Fe3O4@Au Nanostructures for the Electrochemical Detection of Acrylamid","authors":"E. Saepudin, T. Yuliani, M. A. F. Nasution, M. Khalil, J. Hong, T. Ivandini","doi":"10.7454/mss.v25i3.1232","DOIUrl":"https://doi.org/10.7454/mss.v25i3.1232","url":null,"abstract":"In this study, electrochemical detection of acrylamide using hemoglobin (Hb)-modified core–shell Fe3O4@Au nanostructures was conducted. Fe3O4 nanoparticles (~4.9 nm) and core–shell Fe3O4@Au (5.0–6.4 nm) nanostructures were successfully synthesized by the thermal decomposition method. Electrochemical investigation revealed that the optimum amount of Hb of 2 mg/mL could be immobilized in 0.1 M acetate buffer solution (pH = 6). Moreover, the detection of acrylamide using Fe3O4@Au/Hb was evaluated by the cyclic voltammetry technique. A linear calibration curve (R = 0.98) in the concentration range of 0.1 to 1.0 μM could be achieved with an estimated limit of detection, limit of quantification, and sensitivity of 0.136 μM, 0.453 μM, and 0.4411 μA/μM, respectively. Furthermore, the developed biosensor exhibited high selectivity in the presence of ascorbic acid, melamine, and caffeine. The developed biosensor was applied to the detection of acrylamide in coffee samples and validated using the standard high-performance liquid chromatography (HPLC) method. The concentration of acrylamide in coffee samples was determined to be 37.450 and 35.377 ppm using electrochemical measurement and HPLC, respectively.","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"14 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74749578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Djayanti, Syarifa Arum Kusumastuti, J. A. Fatkhurrahman, A. Purwanto, A. Budiarto, A. Suherman
Cellulose acetate membrane (CAM) was successfully synthesized and characterized from the cotton spinning waste of the textile industry. The membrane was produced through the isolation, acetylation, and phase inversion stages. The highest yields of cellulose fiber and α-cellulose contents were obtained using 3.0% and 6.0% v/v NaClO, respectively. The C–O acetyl bond detected by Fourier Transform Infrared (FTIR) analysis indicates the formation of the CAM. The resulting membrane can be potentially applied as an ultrafiltration membrane for water desalination purposes in water and wastewater treatment facilities. Furthermore, the utilization of cotton spinning waste as raw material aims to produce inexpensive products and recycle solid waste from the textile industry.
{"title":"Synthesis and Characterization of Cellulose Acetate Membrane from Cotton Spinning Waste","authors":"S. Djayanti, Syarifa Arum Kusumastuti, J. A. Fatkhurrahman, A. Purwanto, A. Budiarto, A. Suherman","doi":"10.7454/mss.v25i3.1219","DOIUrl":"https://doi.org/10.7454/mss.v25i3.1219","url":null,"abstract":"Cellulose acetate membrane (CAM) was successfully synthesized and characterized from the cotton spinning waste of the textile industry. The membrane was produced through the isolation, acetylation, and phase inversion stages. The highest yields of cellulose fiber and α-cellulose contents were obtained using 3.0% and 6.0% v/v NaClO, respectively. The C–O acetyl bond detected by Fourier Transform Infrared (FTIR) analysis indicates the formation of the CAM. The resulting membrane can be potentially applied as an ultrafiltration membrane for water desalination purposes in water and wastewater treatment facilities. Furthermore, the utilization of cotton spinning waste as raw material aims to produce inexpensive products and recycle solid waste from the textile industry.","PeriodicalId":18042,"journal":{"name":"Makara Journal of Science","volume":"10 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84941389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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