Nunik Gustini, Debora Christin Purbani, Mega Ferdina Warsito, Riyona Desvy Pratiwi, Diah Radini Noerdjito, Fiddy Semba Prasetiya, Nico Rahman Caesar, Uun Yanuhar, Firli Rahmah Primula Dewi, Arien Dwitrie, A’liyatur Rosyidah
Sustainable nanomaterial synthesis has emerged as a critical strategy to reduce the environmental burden associated with conventional chemical synthesis method. Microalgae-derived biomolecules offer a promising platform for the green production of metal nanoparticles due to their rich bioactive compounds capable of acting as natural reducing and stabilizing agents. Here, we report the eco-friendly synthesis of gold nanoparticles (AuNPs) using extract of Indonesian microalga Chlorella vulgaris extract. To optimize the synthesis process, the effects of precursor-to-extract ratio, temperature, and incubation time were evaluated. Optimal synthesis of C5-AuNPs was obtained at 37 °C for 20 h with precursor to extract ratio of 6:4, resulting in moderately stable C5-AuNPs characterized by a surface plasmon resonance (SPR) peak at 541 nm. Furthermore, Fourier-transmission infra-red (FT-IR) analysis revealed the involvement of functional groups of C. vulgaris extract in the interaction with Au+ during the production of C5-AuNPs. Transmission electron microscopy (TEM) demonstrated the formation of uniformly spherical nanoparticles with an average diameter of approximately 8.8 nm. Biological evaluation showed that the synthesized C5-AuNPs exerted pronounced dose-dependent cytotoxicity against MCF-7 breast cancer cells with an IC50 threshold of 21.17 ppm, while no toxicity appears in normal HEK293 cells. Mechanistically, the C5-AuNPs induced early apoptosis and inhibit cell-cycle progression at the stage of G0/G1. Collectively, these findings demonstrate that C. vulgaris-mediated AuNPs represent a promising preliminary in vitro findings for cancer therapy candidate. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026.
Research Center for Vaccine and Drugs, Research Organization for Health, National Research and Innovation Agency (BRIN), Bogor, Indonesia; Research Center for Biosystematics and Evolution, Research Organization for Life Science, National Research and Innovation Agency (BRIN), Bogor, Indonesia; Research Center for Applied Microbiology, Research Organization for Life Science, National Research and Innovation Agency (BRIN), Bogor, Indonesia; Aquatic Resource Management Study Program, Faculty of Fisheries and Marine Science, Universitas Brawijaya, Malang, Indonesia; Biology Department, Faculty of Science and Technology, Universitas Airlangga, Surabaya, Indonesia; In Vitro Imaging Laboratory, Genomic Building, Ir. Soekarno Science and Technology Park, National Research and Innovation Agency (BRIN), Bogor, Indonesia
