DEVELOPMENT OF BIONANOINSECTICIDE USING GREEN SYNTHESIS OF ZINC OXIDE NANOPARTICLES - MORINGA OLEIFERA L LEAF EXTRACT (ZNO-NMO) AS AN EFFORT TO CONTROL MALARIA VECTORS

• Main Author: Estorina Mau Kawa, Endang
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/84947
• Institution: Institut Teknologi Bandung

Malaria remains to be one of the most widely spread infectious diseases globally. Plasmodium genus parasites in humans are exclusively transmitted through the bite of female Anopheles mosquitoes. An effective way to control malaria is to prevent contact between human and vectors such as larvicide use, massively insecticide-treated bed nets and Indoor Residual Spraying (IRS). The district of West Sumba carried out IRS in 2019 in Gaura village using Bendiocarb 0.2 gr/m2 that worked as an acetylcholinesterase (AchE) inhibitor. The continuous exposure to synthetic insecticides can trigger resistance in vectors so monitoring insecticide resistance is very important. Based on the results of the preliminary test of monitoring the status of vector resistance conducted in 2022, the F1 susceptibility test of the test mosquito showed resistance to bendiocarb 0.1%, namely there was 80% mortality of the test mosquito which was later molecularly confirmed to be Anopheles vagus (OM974188.1). Due to this potential vector resistance, an alternative insecticide that is safe and has the ability to cause low mosquito resistance is needed. Zinc oxide nanoparticle (ZnO NP) is widely developed in many applications including biomedicine through the green synthesis method. Moringa leaves (Moringa oleifera L) contain various Phytochemical compounds with many benefits, one of which is as a larvicidal and can be used as a reducer and stabilizer agent in ZnO NP synthesis. This study aims to biosynthesize ZnO NP using Moringa leaf extract and to investigate its insecticidal potential in vivo. Extraction of M. oleifera leaves used 96% ethanol as solvent. Phytochemical compound identification of Moringa leaf extract (EMo) was done qualitatively, and used GC-MS and LC-MS. Molecular docking was analyzed on 25 phytochemical compounds of EMo and AChE protein of Anopheles gambiae (PDB ID: 5x61). ZnO NPs were synthesized using M. oleifera (ZnO-NMo) followed by characterization of the synthesis results and acute toxicity tests on Anopheles maculatus instar III to determine the LC50 value and LC90 value. The statistical test used One-Way ANOVA test. According to the results, EMo qualitative phytochemical test showed the content of saponins, flavonoids, alkaloids, phenolics, steroids, tannins and terpenoids, GC-MS test identified 34 volatile phytochemical compounds while in LC-MS test identified 16 soluble phytochemical compounds. The molecular docking results revealed 7 compounds that have higher Binding Affinity (BA) than the control Bendiocarb (-6.7), and Tamephos (-6.2) which are 4-cyanocinnoline (-8.5), luteolin (-8.5), quersetin (-8.5), myricetin (7.7), kaempherol (-7.5), beta-bergamotene (-7.3), phytol (-6.8). The characterizations of ZnO-NMo nanoparticles used UV-Vis spectrophotometer that showed the wavelength was at the peak of 365 nm. Based on the results of the Fourier Transform Infrared (FTIR) spectra analysis, the functional groups of EMo phytochemical compounds involved in the synthesis of ZnO-NMo were observed. The observed particle size using High Resolution Transmission Electron Microscopy (HR-TEM) and ImageJ analysis was 13.2 nm with spherical morphology. Particle Size Analyzer (PSA) showed the particle size of ZnO-NMo solute was in the range of 40.6 nm ± 4.6 nm, meanwhile the surface charge of ZnO-NMo was -54.5 mV based on the measurement on Zeta Potential Analyzer (ZPA). The analysis of ZnO-NMo crystallinity on X-ray Diffraction (XRD) spectra using JCPDS reference No.00-036-14z 51 showed that the synthesized ZnO-NMo was hexagonal wurtzite crystal with an average crystallite size of 15.6 nm with crystallinity degree equal to 61.06%. Based on the probit results of the toxicity test on Anopheles maculatus, the LC50 24-hour exposure to EMo was 1,900 ppm while the exposure to ZnO-NMo was 380 ppm. The mean mortality of mosquito larvae increased with increasing concentration of EMo and ZnO-NMo (p<0.05). Based on the results of the research conducted, it can be concluded that Moringa (M. oleifera) leaf extract can be used for green synthesis of ZnO NPs and has the potential to have bionanoinsecticidal activity with non-hazardous category toxicity.