Effect of Citric Acid Addition on the Characteristics of Silver Nanoparticles Synthesized via Green Synthesis Using Spent Coffee Grounds Extract

Satria Putra Jaya Negara; Andi Eka Kartika; Nur Afni

doi:10.32734/jcnar.v8i1.27017

Authors

Satria Putra Jaya Negara Department of Chemistry, Faculty of Mathematics and Natural Sciences, Makassar State University, Parang Tambung, Makassar 90224, Indonesia
Andi Eka Kartika Department of Chemistry, Faculty of Mathematics and Natural Sciences, Makassar State University, Parang Tambung, Makassar 90224, Indonesia
Nur Afni Department of Chemistry, Faculty of Mathematics and Natural Sciences, Makassar State University, Parang Tambung, Makassar 90224, Indonesia

DOI:

https://doi.org/10.32734/jcnar.v8i1.27017

Keywords:

Spent Coffee Grounds, Silver Nanoparticles, Green Synthesis, Citric Acid, UV-Visible Spectroscopy, Particle Size Analyzer

Abstract

Spent coffee grounds (SCG) are an abundant coffee-processing waste containing bioactive compounds with potential as natural reducing and stabilizing agents in the green synthesis of silver nanoparticles (AgNPs). This study aimed to optimize the reaction time for AgNP synthesis using methanolic SCG extract and evaluate the effect of citric acid as an additional stabilizing agent. AgNPs were synthesized using methanolic SCG extract and silver nitrate at reaction times of 0, 30, 60, 90, and 120 min. The formation of AgNPs was monitored using UV-Visible spectrophotometry, while particle-size characteristics were evaluated using Particle Size Analyzer (PSA). The characteristic surface plasmon resonance (SPR) band appeared at approximately 424 nm, with the highest absorbance of 1.30 obtained at 60 min. Prolonging the reaction to 90 and 120 min resulted in decreased absorbance, indicating that longer reaction times did not further improve the optical response of the AgNPs. Therefore, 60 min was selected as the optimum reaction time. At the optimum reaction time, 0.1 mM citric acid was added as an additional stabilizing agent. PSA analysis showed that unstabilized AgNPs had D10, D50, and D90 values of 34.48, 65.83, and 125.64 nm, respectively, with a PI of 0.289. After citric acid addition, these values decreased to 30.33, 55.96, and 103.11 nm, respectively, with a PI of 0.255. These results indicate that citric acid improved particle dispersion and reduced the contribution of larger particle populations. The study demonstrates the potential of methanolic SCG extract for green AgNP synthesis and citric acid as an additional stabilizing agent.

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References

[1]. CK V, GB KK, M H, BK M. A Review on Silver Nanoparticles: Synthesis Approaches, Properties, Characterization and Applications. Pharm Nanotechnol. 2026 Mar;14(2):247–59.

[2]. Eker F, Akdaşçi E, Duman H, Bechelany M, Karav S. Green Synthesis of Silver Nanoparticles Using Plant Extracts: A Comprehensive Review of Physicochemical Properties and Multifunctional Applications. Int J Mol Sci. 2025 Jun 27;26(13):6222.

[3]. Tarannum N, Divya D, Gautam YK. Facile green synthesis and applications of silver nanoparticles: a state-of-the-art review. RSC Adv. 2019;9(60):34926–48.

[4]. Zuorro A, Iannone A, Miglietta S, Lavecchia R. Green Synthesis of Silver Nanoparticles Using Spent Coffee Ground Extracts: Process Modelling and Optimization. Nanomaterials. 2022 Jul 28;12(15):2597.

[5]. Yust BG, Rao NZ, Schwarzmann ET, Peoples MH. Quantification of Spent Coffee Ground Extracts by Roast and Brew Method, and Their Utility in a Green Synthesis of Gold and Silver Nanoparticles. Molecules. 2022 Aug 11;27(16):5124.

[6]. Nithiskanna N, Kamal Rufadzil NAM, Murally JB, Liam JZ, Wan NDWF, Hawa Dalily MJ, et al. Green Synthesis and Characterization of Silver Nanoparticles Using Rice (Oryza sativa) and Spent Coffee (Coffea robusta) Grounds from Agricultural Waste. Food Technol Biotechnol. 2025 May 8;63(2):159.

[7]. Kusumahastuti DKA, Gintu AR. Green nanotechnology: silver nanoparticle synthesis via brewed coffee grounds extract. J Incl Phenom Macrocycl Chem. 2025 Apr 6;105(3–4):241–7.

[8]. Panzella L, Cerruti P, Aprea P, Paolillo R, Pellegrino G, Moccia F, et al. Silver nanoparticles on hydrolyzed spent coffee grounds (HSCG) for green antibacterial devices. J Clean Prod. 2020 Sep;268:122352.

[9]. Boughbina-Portolés A, Sanjuan-Navarro L, Moliner-Martínez Y, Campíns-Falcó P. Study of the Stability of Citrate Capped AgNPs in Several Environmental Water Matrices by Asymmetrical Flow Field Flow Fractionation. Nanomaterials. 2021 Apr 5;11(4):926.

[10]. Marciniak L, Nowak M, Trojanowska A, Tylkowski B, Jastrzab R. The Effect of pH on the Size of Silver Nanoparticles Obtained in the Reduction Reaction with Citric and Malic Acids. Materials (Basel). 2020 Nov 29;13(23):5444.

[11]. Tu NC, Sang HM, Anh LTL, Lam NH. Eco-Friendly Synthesis and Applicability to Silver Ink of Silver Nanoparticles Prepared via Stepwise-Modified Tollens Method. J Nanosci Nanotechnol. 2021 Apr 1;21(4):2568–75.

[12]. Deshpande JB, Chakrabarty S, Kulkarni AA. Heterogeneous nucleation in citrate synthesis of AgNPs: Effect of mixing and solvation dynamics. Chem Eng J. 2021 Oct;421:127753.

[13]. Maulana SA, Widiyanto S, Khoerul M. Evaluation of Arabica coffee pulp extract on sperm quality and hematology in cyclophosphamide-treated rats. 2026;41(1):1–18.

[14]. Mussatto SI, Ballesteros LF, Martins S, Teixeira JA. Extraction of antioxidant phenolic compounds from spent coffee grounds. Sep Purif Technol. 2011 Nov;83:173–9.

[15]. Srikhao N, Ounkaew A, Kasemsiri P, Theerakulpisut S, Okhawilai M, Hiziroglu S. Green synthesis of silver nanoparticles using the extract of spent coffee used for paper-based hydrogen peroxide sensing device. Sci Rep. 2022 Nov 22;12(1):20099.

[16]. Corciov A, Mircea C, Burlec AF, Fifere A, Moleavin IT, Macovei I, et al. Green Synthesis and Characterization of Silver Nanoparticles Using a Lythrum salicaria Extract and In Vitro Exploration of Their Biological Activities. 2022.

[17]. Hasri H, Dini I, Negara SPJ, Subaer S. Biosynthesis of Silver Nanoparticles Made from Green Tea Leaf Extract (Camellia sinensis). Mater Sci Forum. 2019 Aug 16;967:161–7.

[18]. Wei L, Lu J, Xu H, Patel A, Chen Z-S, Chen G. Silver nanoparticles: synthesis, properties, and therapeutic applications. Drug Discov Today. 2015 May;20(5):595–601.

[19]. Banerjee P, Satapathy M, Mukhopahayay A, Das P. Leaf extract mediated green synthesis of silver nanoparticles from widely available Indian plants: synthesis, characterization, antimicrobial property and toxicity analysis. Bioresour Bioprocess. 2014 Dec 24;1(1):3.

[20]. Chien H-W, Kuo C-J, Kao L-H, Lin G-Y, Chen P-Y. Polysaccharidic spent coffee grounds for silver nanoparticle immobilization as a green and highly efficient biocide. Int J Biol Macromol. 2019 Nov;140:168–76.

[21]. Liaqat N, Jahan N, Khalil-ur-Rahman, Anwar T, Qureshi H. Green synthesized silver nanoparticles: Optimization, characterization, antimicrobial activity, and cytotoxicity study by hemolysis assay. Front Chem. 2022 Aug 29;10.

[22]. Ünüvar Ü, Aslan TN, Pehlivanoğlu S, Coşkuner KE. Controlling Growth of Ultrasmall Sub‐10 nm Silver Nanoparticles From Cotinus coggygria Scop. Extract and Evaluation of Its In Vitro Anti‐Breast Cancer, Antioxidant and Antimicrobial Activity. J Appl Toxicol. 2026 Jul 21.

[23]. El-Desouky N, Shoueir K, El-Mehasseb I, El-Kemary M. Synthesis of silver nanoparticles using bio valorization coffee waste extract: photocatalytic flow-rate performance, antibacterial activity, and electrochemical investigation. Biomass Convers Biorefinery. 2023 Nov 17;13(17):15871–85.

[24]. Bélteky P, Rónavári A, Zakupszky D, Boka E, Igaz N, Szerencsés B, et al. Are Smaller Nanoparticles Always Better? Understanding the Biological Effect of Size-Dependent Silver Nanoparticle Aggregation Under Biorelevant Conditions. Int J Nanomedicine. 2021 Apr;Volume 16:3021–40.