INTRODUCTION Papaya Ring Spot Virus was one of the most destructive diseases which was transmitted by aphids in a non-persistent manner (Kalleshwaraswamy et al., 2010). Papaya Ring Spot Virus (PRSV) is a member of the genus potyvirus and the family potyviridae which infects papaya (Ashwini et al., 2021; Chalak et al., 2017) and is transmitted through aphids (Thirugnanavel et al., 2015). Apart from the cultivated varieties, some wild-type relatives showed resistance activity against the Papaya Ring Spot Virus Disease. Studies on the assessment of plant essential oils against the aphid species Myzus persicae were also done (Pascual-Villalobos et al., 2019). Essential oil compounds (EOCs) are molecules that have well-documented antimicrobial and anti-pest activity (Fernández-Peña et al., 2019). Dodecanoic acid (Lauric acid) a bioactive compound present in the wild genotype of papaya belongs to a saturated fatty acid member of the sub-group of medium-chain fatty acid with a bright white, powdery solid which is insoluble in water and acts as a molecular entity capable of donating a hydron to an acceptor. Numerous studies have found that fatty acids (FAs) affect plant basal resistance to bacterial and fungal pathogens, but there have been few reports on antiviral agents (Zhao et al., 2017). Dodecanoic acid was responsible for the antiviral activity against the groundnut bud necrosis virus (Sangeetha et al., 2020). Dodecanoic acid was considered the most active inhibitor of the virus (Liang et al., 2021) without affecting cell viability and inhibited a late maturation stage in the replicative cycle of Junin virus (Bartolotta et al., 2001). Though these bioactive compounds are fatty acids there is a need that they should be emulsified for further application in plants. Therefore, microemulsion systems havea wide range of technological applications as microemulsion is a thermodynamically stable isotopic liquid mixture of oil, water, surfactant, and co-surfactant (Xavier-Junior et al., 2016). A series of oil in water (O/W) microemulsions were prepared at a constant temperature using the drop-by-drop method with Span80/Tween80 as the composite emulsifying system and Macol-52 as the oil phase (Chen et al., 2020). Thus, microemulsion requires high surfactant levels to provide an interfacial surface to completely microemulsify the compounds and also to provide formulation stability to temperature and storage. The three basic types of microemulsions are direct (oil-in-water), reversed (water-in-oil), and bicontinuous based on thermodynamic stability (Yadhav et al., 2018). In microemulsion systems, where two immiscible phases (water and oil) are present with a surfactant that forms a monolayer at the interface between oil and water. Studies on microemulsions showed that the use of microemulsions as a delivery platform improves the targeted action. The Fourier transform infrared (FT-IR) spectroscopy was used in this study to record the infrared spectrum of absorbance and transmission of the microemulsion. MATERIALS AND METHODS Materials. This study was carried out in the Department of Fruit Science and the Department of Nanoscience & Technology, TNAU, Coimbatore to prepare and characterize dodecanoic acid microemulsion. Dodecanoic acid (Lauric acid) purchased from Sigma Aldrich and MCT oil purchased from Smy oils limited (medium-chain triglycerides) was used as the oil phase and tween 80 as a surfactant, span20 as a surfactant, glycerol as co-surfactant, and distilled water was used as the aqueous phase for the preparation of the microemulsions. Magnetic stirrer, magnetic beads (size-25mm), micropipette (100microlitre), beaker, and aluminium foils are used. The oil-in-water microemulsion was prepared in two phases oil phase and aqueous phase, Dodecanoic acid (10mg) + MCT oil (10ml) was used inthe oil phase and tween 80 (surfactant) + span 20 (surfactant) + glycerol at different concentrations are used in the aqueous phase. Using magnetic stirrer microemulsion was prepared, and FT-IR spectroscopy analysis. CHARACTERIZATION: FT-IR spectroscopy FT-IR spectroscopy of model FT/IR-6800 typeA was used to obtain the infrared spectrum and it was recorded between 4000-400 cm-1. The IR spectrum table and chart lists IR spectroscopy frequency ranges, the appearance of the vibration, and absorption for functional groups by frequency range and compound class (Sigma-Aldrich). RESULT AND DISCUSSION Papaya Ring Spot Virus resulted in severe yield loss and much more disease incidence (Premchand et al., 2021). Many plants naturally possess bioactive compounds to protect themselves from several diseases by enhancing the resistance capability of the plants and also these bioactive compounds from plants are non-phytotoxic and not harmful to the environment. The GC-MS analysis indicated that dodecanoic acid a bioactive compound that was present in the wild genotype of papayas such as Vasconcellea candamarcensis (72.8%) and CO.7 (17%) a cultivated variety of papaya, but absent in wild types and other cultivated varieties (Gohilapriya et al., 2021). Numerous studies have found that fatty acids (FAs) affect plant basal resistance to bacterial and fungal pathogens, but there have been few reports on antiviral agents (Zhao et al., 2017). Dodecanoic acid was considered to be the most active inhibitor of the virus (Liang et al., 2021) without affecting cell viability and inhibited a late maturation stage in the replicative cycle of Junin virus (Bartolotta et al., 2001). For preparing microemulsion the solubility of Dodecanoic acid was checked by dissolving it in ethanol, MCT oil, castor oil, and distilled water and it was dissolved in MCT oil, castor oil, and ethanol rather than distilled water, this shows the solubility of the dodecanoic acid (lauric acid). Dodecanoic acid was encapsulated in medium-chain triglycerides (MCT oil), tween 80, span 20, and glycerol as emulsifiers under different concentrations of oil-in-water microemulsion prepared. The result showed that from different concentrations prepared, dodecanoic acid + MCT oil in the oil phase and distilled water + span 20 + tween 80 + glycerol in the aqueous phase showed greater stability and lesser particle size, and the pH of the microemulsion under different concentrations of LA1, LA2, LA3, LA4 as 7.0, 7.2, 7.3, 7.0 respectively. From FT-IR spectroscopy the infrared spectrum of the functional group of microemulsion was found by frequency range and compound class. The above oil-in-water microemulsion prepared from bio-active compounds can be used against plant viruses, as they are responsible for anti-viral activity in plants due to the presence of ribosome-inactivating protein (Sangeetha et al., 2020). Further confirmation studies are required to study the stability of the preparation as well its efficiency against Papaya Ring Spot Virus (PRSV).