SINTESIS NANOPARTIKEL PERAK EKSTRAK METANOL DAUN SANGITAN (Sambucus javanica R.) SEBAGAI PENGENDALI JAMUR Curvularia verruculosa PADA TANAMAN PADI (Oryza sativa)

Abstract

         Curvularia verruculosa is a pathogenic fungus of rice plants that causes brown spot disease and substantial yield reduction. Conventional control methods relying on synthetic fungicides pose risks of pathogen resistance and environmental degradation. Alternatively, the leaves of Sambucus javanica R., which are rich in secondary metabolites, such as flavonoids, saponins, and tannins, exhibit potent antifungal properties that are more environmentally friendly. These bioactive compounds facilitate a green synthesis approach, serving as stabilizing and reducing agents in the formation of nanomaterials. Therefore, this study aimed to synthesize silver nanoparticles (AgNPs) using a methanol extract of S. javanica leaves, characterize their physicochemical properties, and evaluate their antifungal efficacy against C. verruculosa. Extraction was performed using the maceration method, and the resulting extract served as both a reducing and stabilizing agent in the synthesis of AgNPs from silver nitrate (AgNO₃). Characterization was conducted using UV-Vis spectrophotometry, Particle Size Analysis (PSA), Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX), and Fourier Transform Infrared Spectroscopy (FTIR). The UV-Vis spectra exhibited an absorption peak at 413 nm, confirming the successful formation of nanoparticles. The average particle size was determined to be 512.4 nm with a polydispersity index (PDI) of 0.4208 and a zeta potential of –28.51 mV. SEM-EDX analysis revealed that the AgNPs possessed smooth surfaces with minimal aggregation and identified the presence of carbon (C), oxygen (O), potassium (K), chlorine (Cl), phosphorus (P), and silver (Ag). FTIR spectra confirmed the presence of hydroxyl and carbonyl groups, along with organic bonds such as C–O, C–H, and C–N. Antifungal assays demonstrated that the AgNPs exhibited superior activity compared to the crude extract, yielding an inhibition zone of 25.3 mm. Furthermore, the Minimum Inhibitory Concentration (MIC) was established at 2% with an inhibition zone of 10 mm.

ABSTRAK

         Curvularia verruculosa merupakan patogen pada tanaman padi yang menyebabkan bercak cokelat dan penurunan hasil panen. Pengendalian yang dilakukan umumnya menggunakan fungisida sintetis yang dapat menimbulkan resistensi patogen dan dampak lingkungan. Sebagai alternatif, fungisida alami seperti daun sangitan (Sambucus javanica R.) yang kaya akan metabolit sekunder seperti flavonoid, saponin, tanin dan lainnya berpotensi sebagai antijamur yang lebih ramah lingkungan. Potensi senyawa aktif tersebut memungkinkan pemanfaatannya dalam pengembangan teknologi hijau sebagai agen penstabil dalam pembentukan material nano. Oleh karena itu, penelitian ini bertujuan mensintesis nanopartikel perak (AgNP) menggunakan ekstrak metanol daun sangitan, kemudian mengkarakterisasi sifat fisikokimianya, serta mengevaluasi aktivitas antijamurnya terhadap Curvularia verruculosa. Ekstraksi dilakukan dengan metode maserasi, dan ekstrak digunakan sebagai agen pereduksi dan penstabil dalam sintesis NPAg menggunakan AgNO₃. Karakterisasi dilakukan menggunakan Spektrofotometer UV-Vis, Particle Size Analyzer, Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy, dan Fourier Transform Infrared Spectroscopy. Hasil pengukuran spektra UV-Vis menunjukkan panjang gelombang 413 nm, menandai terbentuknya nanopartikel. Ukuran partikel utama didapatkan sebesar 512,4 nm, PI 0,4208, dan zeta potensial –28,51 mV. Analisis Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy menunjukkan AgNPs berpermukaan halus dengan sedikit agregasi, serta mendeteksi unsur C, O, K, Cl, P, dan Ag. Spektrum FTIR mengonfirmasi keberadaan gugus hidroksil, karbonil, dan ikatan organik seperti C–O, C–H, dan C–N. Uji antijamur menunjukkan NPAg memiliki aktivitas lebih tinggi dibandingkan ekstrak kasar dengan zona hambat 25,3 mm, sedangkan KHM tercapai pada konsentrasi 2% dengan zona hambat 10 mm.

Kata kunci: nanopartikel perak, Sambucus javanica R., Curvularia verruculosa, antijamur, biosintesis