Clove Leaf Extract Research Articles

Extract Clove Leaves Were Used to Test the Effectiveness of Hand Washing Soap. Aedes Aegypti Mosquito Larvae Syzygium Aromaticum L Exterminator

The best method for getting rid of mosquito larvae is to employ biological pesticides derived from plants, such as Syzygium aromaticum L.'s clove leaf extract. Aedes aegypti larvae can be killed by a clove leaf extract containing eugenol, saponins, flavonoids, and tannins. Insect repellent hand soap prepared from Syzygium aromaticum L clove leaf extract is being tested to see how well it works against Aedes aegypti mosquito larvae. This study uses an experimental design with a post-test and a control group, including three treatment and three control groups. A sample of 20 larvae was taken from each group and the control three times. So that there were 280 Aedes aegypti larvae in the sample, 60, 80, and 100 mL of hand soap prepared from Syzygium aromaticum L. clove leaf extract were used, respectively. Within 24 hours, observations were taken, and the number of larvae perished each hour was recorded. The outcomes demonstrated that the amount of Aedes aegypti larvae mortality in the treatment of 60 mL, 80 mL, and 100 mL was extremely effective, being able to kill 100 percent with three repetitions in one hour, non-treatment (negative control) 0 percent larvae mortality in time of 24 hours, and the control treatment of hand washing soap without clove leaf extract was less effective, it could only kill 50 percent within 24 am, while the control treatment with clove was more effective. The mortality of mosquito larvae is significantly influenced by the concentration of hand soap made from clove leaf extract Syzygium aromaticum L, which occurs extremely quickly. To promote public awareness and comprehension of natural larvae exterminators, there is a need to educate people about the risks of DHF and how to prevent it with natural components. The findings of this study are anticipated to be used in the future to improve health conditions.

In Vitro Analysis of Effectiveness Clove Leaf Extract (Syzygium aromaticum) Against Anthracnose Disease (Colletotrichum capsici) on Chili Plants (Capsicum annum L)

Chili (Capsicum annum L) is a plant with a high economic value and is in great demand by the Indonesian people. This research aimed to determine the effectiveness of the difference in the concentration of clove leaf extract in inhibiting anthracnose disease in chili. This research was conducted from February to April 2022. This research used the Complete Randomized Design (CRD) method with six treatments and four replications. The treatment used in this research was the difference in the concentration of clove leaf extract, namely 0%, 1%, 2%, 3%, 4%, and 5%. The research showed that clove leaf extract could inhibit the growth of C. capsici, which caused anthracnose disease in chili. In vitro tests showed that the concentrations of 3%, 4%, and 5% of clove leaf extract significantly differed from all treatments and had fungicidal properties against C. capsici. In conclusion, the research results showed that the effective concentration in inhibiting the growth of C. capsici, which causes anthracnose disease in chili, is the concentration of clove leaf extract 3%, 4%, and 5%.

UJI EFEKTIVITAS EKSTRAK DAUN CENGKEH (Syzygium aromaticum) PADA NYAMUK Aedes aegypti SEBAGAI ANTI NYAMUK RAPELAN

Dengue Hemorrhagic Fever (DHF) is an infectious disease caused by the dengue virus and transmitted through the bite of the Aedes aegypti mosquito. The number of dengue fever patients reported was 3,444 cases in 2016. The use of irrational chemical insecticides has caused adverse effects on the environment, such as the emergence of resistant vectors or pests against these insecticides. Seeing this, it is necessary to make an effort to get alternative insecticides, namely by using the wrong natural insecticides, namely with clove leaves (Syzygium aromaticum). This study aims to determine the effectiveness of clove leaf extract (Syzygium aromaticum) on the Aedes aegypti mosquito as a mosquito repellent anti-mosquito and the most effective concentration of test extract. The type of research used is experiment. The population in this study were clove leaves (Syzygium aromaticum), the sample in this study was 231.81 grams of clove leaf extract (Syzygium aromaticum), using maceration method. The results of this study obtained an average percentage of mosquitoes that landed using the test material, namely clove leaf extract (Syzygium aromaticum) with a concentration of 4%, namely 70%, 8% concentration of 40%, 16% concentration of 30%, and control test material ( X-Spray) is 0% and the most effective concentration of clove leaf extract (Syzygium aromaticum) is 16% concentration.
 Keywords : Aegypti Mosquito, Clove Leaf, Extract
 

Apoptosis in Yeast is Modulated by Clove Leaf Extract and Eugenol Potentially by Interfering Caspase YCA1

Apoptosis in Yeast is Modulated by Clove Leaf Extract and Eugenol Potentially by Interfering Caspase YCA1

RESPONS HAMA Spodoptera litura F. TERHADAP PESTISIDA BOTANIS Cymbopogon nardus L Rendl., Pangium edule Reinw., dan Syzigium aromaticum L. PADA TANAMAN Brassica olearacea L.

This study aims to studying the effect of extracts of citronella, pangi leaves, and clove leaves on the mortality of S. litura larvae, the number of S. litura pupae formed and the inhibition of feeding activity of S. litura larvae on cabbage plants. This research was conducted at the Laboratory of the Protection and Quality Testing of Food Crops and Horticulture of North Sulawesi Province and the Laboratory of the Agriculture and Fisheries Service of Tomohon City from November 2020 to July 2021. The research method used a completely randomized design consisting of 3 treatments and 5 replications. The results showed that citronella extract, pangi leaf extract and clove leaf extract could control the mortality of S. litura larvae, the number of pupae of S. litura larvae formed and inhibit the feeding activity of S. litura larvae.

RESPONS HAMA Spodoptera litura F. TERHADAP PESTISIDA BOTANIS Cymbopogon nardus L Rendl., Pangium edule Reinw., dan Syzigium aromaticum L. PADA TANAMAN Brassica olearacea L.

This study aims to studying the effect of extracts of citronella, pangi leaves, and clove leaves on the mortality of S. litura larvae, the number of S. litura pupae formed and the inhibition of feeding activity of S. litura larvae on cabbage plants. This research was conducted at the Laboratory of the Protection and Quality Testing of Food Crops and Horticulture of North Sulawesi Province and the Laboratory of the Agriculture and Fisheries Service of Tomohon City from November 2020 to July 2021. The research method used a completely randomized design consisting of 3 treatments and 5 replications. The results showed that citronella extract, pangi leaf extract and clove leaf extract could control the mortality of S. litura larvae, the number of pupae of S. litura larvae formed and inhibit the feeding activity of S. litura larvae.

The influence of clove leave extract (Syzygium aromaticum) on growth performance and bacterial population of broiler chickens raised in stressful conditions of high stocking density

Broilers maintenance at high stocking density impacts uncomfortable conditions; this increases the potential for stress, reduces feed consumption, and reduces production performance and health in broiler chickens. This study aims to evaluate the effect of clove leaf extract on growth performance and microbial population in the digestive tract of broiler chickens reared at high density. From the eighth day, five treatment groups, T0 (negative control with a typical density of 10 birds/m2), T1 (positive control with a high density of 16 birds/m2), T2, T3, and T4 with a high density of 16 birds/m2, were randomly assigned from 444 broilers (bodyweight of 129.78±0.75 g) with six repetitions each on the eighth day. The feed includes clove leave extract as much as 0.5, 0.75, and 1 ml/kg for T2, T3, and T4, respectively. The weight gain, feed intake, and feed conversion ratio were tracked weekly. One chicken from each replicate was taken randomly, slaughtered, and feathered on day 35. The digesta was taken from the ileum and cecum to measure the intestinal bacterial population and put into a sterile container. Digesta from the duodenum, jejunum, ileum, and cecum were also collected to determine pH levels. MRS agar was used to determine the amount of LAB in the digesta. The findings revealed that giving clove leaf extract of feed to broiler chickens kept at high stocking density could higher body weight gain (P < 0.05), higher feed consumption (P < 0.05), decreased the pH of the ileum and cecum (P < 0.05), increased lactic acid bacteria and decreased coliform bacteria in the ileum and cecum (P < 0.05).

Preliminary study on the potential of topical anaesthesia from betel leaf and clove leaf extract

Introduction: Betel leaf (Piper betle Linn.) and clove leaf (Syzygium aromaticum) are Indonesian herbs which are known to cause a numb sensation. The main ingredients of betel leaf, which act as an anesthetic, are caryophyllene, eugenol, methyl eugenol, eucalyptol (1.8-cineol), linalool, α-Pinene, estragole, while cloves have local anesthetic effects through their ingredients, namely eugenol, and β-Caryophyllene. Research on the benefits of these two ingredients as topical anesthetics in Indonesia is still rare. This study was aimed to describe the potential of betel leaf and clove leaf extract as a topical anesthetic in Wistar rats. Methods: This research was a laboratory experimental research with simple randomized controlled design. The sample consisted of 6 male Wistar rats, each of which was given four treatments, namely extract with a concentration of 50%, 75%, and 100%, and topical anaesthetic benzocaine 20% as a control. Each treatment was tested using an electric stimulator and observed onset, duration of action, and depth of topical anaesthesia. The data were processed using descriptive statistics with tables and graphs. Results: Betel leaf extract with a concentration of 100% had a better mean onset, duration of work, and depth of anesthesia than the 20% benzocaine control, whereas 75% clove leaf extract had the longest duration of action compared to 20% benzocaine and 100% concentration was the topical anesthetic agent with the highest anesthetic depth. Conclusion: Based on the onset, duration of action, and depth of anesthesia, betel leaf, and clove leaf have potential as topical anesthetic agents.

Evaluation of the phytochemical content, antimicrobial and antioxidant activity of Cocos nucifera liquid smoke, Garcinia mangostana pericarp, Syzygium aromaticum leaf, and Phyllanthus niruri L. extracts.

Background and Aim:Many plants contain bioactive substances with antibacterial and antifungal properties. The aim of this study was to evaluate the antibacterial and antifungal activity of Cocos nucifera shell liquid smoke (CSL), clove leaf extract (CLE), and mangosteen pericarp extract (MPE) alone and in combination against Escherichia coli and Candida utilis. The antioxidant activity, phenol, saponin, and tannin of CSL, CLE, MPE, and Phyllanthus niruri L. extract were also measured.Materials and Methods:The agar well-diffusion method was used to determine the antimicrobial and antifungal activities of CSL, methanolic MPE, and CLE and their combination CSL+MPE+CLE (COMBI) on bacteria E. coli and fungus (C. utilis). Antioxidant activity was measured by the diphenylpicrylhydrazyl method. Total phenol and total tannin were measured by the Folin–Ciocalteu method and total saponin was measured by the vanillin-sulphate method.Results:The results indicated that phenolic and tannin levels were greater in MPE than in CLE, whereas the saponin content was higher in CLE compared with MPE. Undiluted (100%) MPE exhibited lower antibacterial activity (p<0.05) than chloramphenicol against E. coli, however, undiluted CLE and COMBI showed similar activity compared with chloramphenicol against E. coli. COMBI caused significantly (p<0.05) higher inhibition compared with virginiamycin against E. coli. CSL, MPE, and COMBI exhibited significantly lower antifungal activity (p<0.05) than that of ketoconazole against C. utilis. In contrast, CLE showed improved antifungal activity (p<0.05) compared with ketoconazole.Conclusion:Cocos nucifera liquid smoke, Garcinia mangostana pericarp extract, and Syzygium aromaticum leaf extract, either alone or in combination, have the potential to be used as antibacterial and antifungal agents.

Clove leaf ethanol extract (Syzygium aromaticum L. Merr. and Perr) is formulated as antiseptic liquid soap

Secondary metabolite compound is compound that have medicinal properties, cosmetics, dyes, fragrances. Secondary metabolite compound can be modified into one form of pharmaceutical dosage, namely cosmetic products. One of the cosmetic products is liquid soap preparation. Soap that can kill bacteria is known as antiseptic soap. Clove leaves (Syzygium aromaticum L. Merr. And Perr) contain eugenol compounds which have antiseptic properties. This study aims to determine the effectiveness of the ethanol extract of clove leaves as an antiseptic liquid soap preparation. The formulation of clove leaf extract with concentrations of 5%, 10% and 15% with HPMC concentrations of 1 gr, 2 gr and 3 gr. The liquid soap formulation of clove leaf ethanol extract was tested for organoleptic, pH, specific gravity, high foam and viscosity. The results of testing the quality of all liquid soap formulations meet the requirements according to the standards set by SNI. Based on the evaluation of this liquid soap preparation, the ethanol extraction preparation can be formulated into liquid soap preparations. After being tested for its antibacterial activity, Sedian Liquid Soap from Ethanol Extract of Clove Leaves has effectiveness as an antiseptic.

PERAN TANAMAN SEBAGAI INSEKTISIDA NABATI TERHADAP GIGITAN NYAMUK Aedes aegypt VEKTOR DEMAM BERDARAH DENGUE

Introduction: Dengue hemorrhagic fever (DHF) caused by the female dengue virus Aedes aegypt causes nearly 390 million people to be infected each year. the number of dengue cases is increasing from year to year and extraordinary events (KLB) tend to occur every 5 years. Vector mosquito control still uses chemical insecticides, so alternative insecticides such as plant-based insecticides from plants that are cheap, easy to obtain, environmentally friendly and effective in killing adult mosquitoes are needed.&#x0D; Discussion: Test repelens of some plant extracts are at a dose of 100% which is able to reject mosquito bites above 80% per hour including leaf extracts of Zodia linalol and apinene as mosquito repellent fluids. Tobacco leaf extract is able to resist for 3 hours with the active substances of nicotine and alkaloid tobacco leaves. Gondopuro leaf extract is able to resist for 1 hour containing saponins. Serai Wangi leaf extract can resist for 2 hours because it contains geraniol, citronellol, citronellal, and citral. Clove leaf extract was able to resist for 4 hours as much as 81.7%. Chrysanthemum flower extract was able to resist for 1 hour as much as 89.6%, while suren leaf extract, tuba root and lavender were only able to resist Aedes aegypti mosquito bites below 80%.&#x0D; Conclusion: Plants can be plant-based insecticides and are proven effective in preventing Aedes aegypt mosquito vector bites&#x0D; &#x0D; Keywords: Aedes aegypt, dengue hemorrhagic fever, plant insecticide

Synthesis of silver nanoparticles using bioreductors from clove leaf extract (Syzygium aromaticum) and test of its antibacterial activity

Synthesis of silver nanoparticles using clove leaf extract (Syzygium aromaticum) bioreductor and its antibacterial activity has been studied. Silver nanoparticles were synthesized using the green synthesis method with clove leaf extract (Syzygium aromaticum) as a bioreductor. Nanoparticles were analyzed and characterized by a spectrophotometer by UV-Vis, FTIR, SEM, XRD, and antibacterial activity. Antibacterial activity testing was carried out against Pseudomonas Aeruginosa and Bacillus Subtilis using the disc paper method. Silver nanoparticles were successfully synthesized by a reduction method using clove leaf extract (Syzygium aromaticum). The resulting nanoparticles have varying wavelengths in the range 420-435 nm and have non-uniform shapes with the resulting particle crystal size diameter based on the Debye-Scherer formula is 36.57 nm. FT-IR spectrum comparison of clove leaf extract and silver nanoparticles shows the contribution of the OH functional group in reducing silver ions which is indicated by its presence decrease in absorbance intensity in the area of wave number 3400 cm−1 after the formation of nanoparticles silver. Antibacterial activity of silver nanoparticles against Pseudomonas Aeruginosa and Bacillus Subtilis which showed that the inhibition zone diameter was 11 mm and 9 mm.

EFFECTIVENESS OF LOTION EXTRACT OF VARIOUS TYPE OF PLANTS AS Aedes aegypti MOSQUITO REPPELENT

Effort to control DHF (Dengue Hemorrhagic Fever) vectors without toxic substances by using natural and enviromentally friendly materials was natural repellent made using plants that were widely available in the community.Many types of plants contain various secondary metabolite compound substances that have the potential to be used as natural insecticides, especially as repellent of the Aedes Aegypti mosquito. The research needs to be done to determine the effectiveness of basil leaves, citronella leaves, clove leaves and betel leaves as a repellent against Aedes Aegypti mosquitoes. This research method was an experiment in the laboratory. The materials used for this research were basil leaves, citronella leaves, clove leaves, and betel leaves. The extracted leaves were then made lotions with certain formulas, tested as a natural repellent against Aedes Aegypti mosquitoes. The concentrations used were 20%, 40% and 80% as well as negative control (0%) and positive control (brand x lotions). The number of mosquitoes used in the study were 25 x 4 treatments = 100 mosquitoes. The replication or repetition was done 10 times. To find out the difference in the number of Aedes Aegypti mosquitoes that perch on the hands of probandus which has been smeared with basil leaf, citronella leaf, clove leaf and betel leaf extracts uses Anova Statistical tests and kruskal wallis. To see the difference between concentrations was tested with LSD or Mann-Whitney test. The calculation result of the number of Aedes Aegypti mosquitoes that perch before and after applying the lotion, the lowest was the lotion of citronella leaf extract 0% (11); 20% (2); 40% (1); 80% (1); The highest protection capacity of extract lotion is citronella leaves with concetrations of 20% (81,1%); 40% (95%), 80%(98,2%); There were no significant differences between the lotion concentrations of 20% and 80%, while the concentration of 40% is significantly different. Then the LSD follow-up test finds that the protective capacity of lotion of clove leaf extract is negative and citronella leaf extract is positive. The most effective protection capacity against Aedes Aegypti mosquitoes was lotion of citronella leaf extract with concentration of 40% (95%) and a concentration of 80% (98,2%), proven by the value of protection capacity that is stable even though it has been used for up to 6 hours and can exceed the protection capacity of lotion x (90,3%). It is reccomended that further research needs to be developed to optimize the lotion of citronella leaf extract 40% and 80% with orgonolaptic test of color, aroma, stickness and comfort of its use.

Giving the extract of clove leaves (Syzygium aromaticum L.) fermented through drinking water against growth of kampong chicken

This study aims to determine the microbial population, nutrient digestibility and growth in native chickens fed fermented clove leaf extract through drinking water. The experimental design used was a completely randomized design (CRD) with four treatments and five replications, using three native chickens 2 weeks old in each unit. The treatments were drinking water without fermented clove leaf extract (P0), drinking water given 1% fermented clove leaf extract (P1), drinking water given 2% fermented clove leaf extract (P2), drinking water given 3% fermented clove leaf extract (P3 ). The variables observed were microbial population, nutrient digestibility and growth. The results showed that giving fermented clove leaf extract through drinking water in treatment P1 and P2 resulted in significantly different increase in lactic acid bacteria (P &lt;0.05) compared to the control and treatment P1 reduced pathogenic bacteria Escherichia Coli and Coliform significantly different (P &lt;0, 05) compared to control. Treatment P2 received a higher Total Plate Count (TPC) which was significantly different (P &lt;0.05) compared to P0, P1 and P3. The digestibility values of dry matter, organic matter, crude protein and digestible energy were significantly different in treatment P1 (P &lt;0.05) compared to the control.

HAIR TONIC FORMULATION OF CLOVE LEAVES (SYZYGIUM AROMATICUM) ETHANOL EXTRACT AND THE EFFECTIVENESS ON RABBIT HAIR GROWTH

Objective: The purpose of this study was to determine the physical stability and effectiveness of hair growth in hair tonic preparations containing ethanol extract of clove leaves (Syzygium aromaticum) with a concentration variation of 5, 10, and 15%.&#x0D; Methods: Formulations were evaluated, including organoleptic observation, pH checking, and preparation stability tests using the Climatic Chamber. The effectiveness of clove leaf extract as a hair tonic was tested by looking at hair growth in test animals.&#x0D; Results: The results showed that the preparation was stable at high temperatures (40±2 °C) where the odor, color, clarity, and pH remained constant. Effectiveness test on rabbit hair growth showed significantly different results after measuring hair growth on the 21st day, where the results were 11.83+0.06 mm for positive control, 1.71+0.06 mm as blank, 1.69+0.06 mm for the group without treatment, and successively the results of the group given clove leaf extract 5, 10, and 15% were 4.00+0.06; 4.80+0.06; and 5.46+0.08 mm.&#x0D; Conclusion: Hair tonics containing clove ethanol extract can increase rabbit hair growth.

PENGARUH EKSTRAK DAUN CENGKEH (SYZYGIUM AROMATICUM L.) SEBAGAI REPELLENT TERHADAP JUMLAH LALAT YANG HINGGAP SELAMA PROSES PENJEMURAN IKAN ASIN DI SENGGARANG TAHUN 2019

The content of clove leaves (Syzygium aromaticum L.) which gives rise to the distinctive aroma is a component of essential oils. Repellent use generally does not directly kill insects, but rather serves to resist the presence of insects, mainly due to the pungent odor. The purpose of this study was to determine the effect of using clove leaf extract (Syzygium aromaticum L.) as a repellent when drying salted fish in Sengarang. This experimental research uses after only design. Effect of clove leaf extract as a natural bioinsecticide with concentrations of 15%, 30%, and 60% with once repetition. Analysis using univariate and bivariate analysis, then tested with the One Way Annova statistical test. The results showed the average flies at 15% concentrations were 36 heads, 30% were 4 flies and 60% concentrations were 1 flies. The concentration of clove leaf extract (Syzygium aromaticum L.) which is the most effective as repellent flies when drying salted fish is a concentration of 60%. This research can provide information about alternatef fly repellent when drying salted fish by using natural ingredients namely the use of clove leaf extract (Syzygium aromaticum L.). Next researchers need to take measurements of the density of flies every hour when observing.

THE CARACTERIZATION THE CARACTERIZATION OF SIMPLISIA AND EXTRACT OF CLOVE LEAVES (Syzigium aromaticum Merr. Et Perry L) FOR HERBAL MOUTHWASH ACTIVE INGREDIENS

One of the oral and dental diseases that is often experienced by most people is dental caries. Clove leaves (Syzygium Aromaticum Merr. Et Perry L) have compounds that can prevent the activity of the bacterium Streptococcus mutans which is the cause of dental caries. This research is non experimental which focuses on the characterization of clove leaves. Characterization of simplisia and sample extracts include organoleptic observation, microscopy, phytochemical screening using Thin Layer Chromatography (TLC), determination of soluble substances in certain solvents (ethanol and water), total ash content, water soluble ash content, insoluble ash content in acid, then drying shrinkage test. The results of the organoleptic test for simplisia and extract of clove leaf showed that they have a dark brown color, specific aromatic odor, spicy and bitter taste. Clove leaf extract has a brownish black color, aromatic odor and has a bitter and pungent taste. Microscopic test of simplisia of clove leaves showed that there was a mesophyll includes palisade tissue, with calcium oxalate crystal, anomistic type stomata, identification fragments are fragments of the lower epidermis with stomata. The results of the percentage of soluble substances of simplisia and ethanol extract of clove leaf were 50% and 40%, the percentage of soluble substances of simplisia and ethanol extract of clove leaf were 1.73% and 4.33%. The percentage of total ash content of simplisia and ethanol extract of clove leaf 11.4% and 22%, the percentage of water soluble ash content of simplisia and extract was 16.9%, 17.5%. Percentage of insoluble ash content of simplisia acid and extract 9.5% and 10.5%. Shrinkage of simplisia and extracts were 7.6% and 11.46%.

Effect of Ethanol-Derived Clove Leaf Extract on the Oxidative Stress Response in Yeast Schizosaccharomyces pombe.

Compared to the widely explored antioxidant activity from the clove bud extract, less data are available regarding the potential pharmacological use of clove leaves. Our study aimed to explore the antioxidant activity of clove leaves extract in the cellular level. Thus, we used the yeast Schizosaccharomyces pombe as model organisms. Our data indicate that, following extract treatment (100 ppm), the viability of the stationary phase cells of S. pombe was higher than without extract and that of calorie restriction treatments. 100 ppm extract treatment also increased cell viability against H2O2-induced oxidative stress. Those data indicate that the extract could promote oxidative stress tolerance response in yeast cells, which occurred either during the stationary phase or due to exogenous exposure. Higher dose of extract (500 ppm) showed opposite effects, as cell viability was lower than that without treatment. Analysis toward the mitochondrial activity revealed that the extract did not induce mitochondrial activity unlike the calorie restriction treatment. Based on our data, clove leaf extract promotes oxidative stress tolerance response in the yeast S. pombe, independent to that mitochondrial adaptive ROS signaling which commonly occurs in calorie restriction-induced oxidative stress tolerance response.

Dual Activities of Nano Silver Embedded Reduced Graphene Oxide Using Clove Leaf Extracts: Hg2+ Sensing and Catalytic Degradation

AbstractSilver nanoparticles embedded reduced graphene oxide (rGO−Ag) nanocomposites are synthesized by green technique using clove leaf aqueous extract as reducing agent. The surface plasmon resonance (SPR) peak of silver nanoparticles (Ag NPs) at 410 nm in rGO−Ag nanocomposites is analysed by UV–visible spectroscopy. The intensity of surface plasmon resonance (SPR) peak of Ag NPs in rGO−Ag nanocomposites is decreased with addition of Hg2+ ion at small interval of time. This is due to the occurrence of redox reaction between Ag(0) and Hg2+ and also for the formation Ag/Hg amalgam. The lower limit of detection (LOD) of rGO−Ag nanocomposites for Hg2+ ion is found to be 9.5 nM. Moreover, the rGO−Ag nanocomposites may be used as catalyst for degradation of methylene blue (MB) by sodium borohydride (NaBH4) at ambient temperature. The adsorption efficiency of methylene blue is increased due to hydrogen bonding and electrostatic interaction along with π–π stacking between the catalyst and the dye molecules. The methylene blue is degraded within a small time due to large surface area and more number of active sites of rGO−Ag nanocomposites. The as‐synthesized nanocomposite is a potential hybrid material having dual activity as Hg2+ sensing and catalytic behaviour in degradation of methylene blue.

UJI EFEKTIVITAS SEDIAAN PATCH EKSTRAK DAUN CENGKEH (Syzygium aromaticum) SEBAGAI REPELLENT NYAMUK

Clove (Syzygium aromaticumL.) leaf has efficacy as repellent because it contains terpenoid eugenol. This study aimed to determine how the effectiveness of clove leaf extract patch dosage as a mosquito repellent. This research was started with extraction using maceration method with 96% ethanol solvent. Furthermore, making the dosage of patch of clove leaf extract using matrix method with variation of the clove leaf extract concentration. Then, the effectiveness of mosquito repellent patch was tested by using rabbit that divided into 5 treatment groups namely K- (base patch), K+ (mosquito repellent patch), 3 groups of clove leaf extract patch with variation of concentration of F1a (concentration of 1%), F1b (concentration of 3%), and F1c (concentration of 5%). Each group was attached to the clothes of the rabbit and put into the experimental box that had been put by mosquito as many as 20 tails. Based on result of ANNOVA statistic test showed that clove (Syzygium aromaticumL.) leaf patch dosage against the rabbit gave a significant effect against mosquito repellent, where at 5% concentration of clove leaf extract could give mosquito repellent efficacy better than concentration 1% and 3%.