Controlling the absorption region of multi-shaped silver nanoparticles for SERS applications
Authors:   Faculty of Materials Science and Technology, University of Science, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Vietnam, Nguyen Le Ngoc Thu ,   Vietnam National University, Ho Chi Minh City (VNU-HCM) 700000, Vietnam, Luong Hoai Nhan ,   Faculty of Materials Science and Technology, University of Science, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Vietnam; Vietnam National University, Ho Chi Minh City (VNU-HCM) 700000, Vietnam, Pham Ngoc Bao Tri ,   Faculty of Materials Science and Technology, University of Science, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Vietnam; Vietnam National University, Ho Chi Minh City (VNU-HCM) 700000, Vietnam, Le Thai Duy ,   Faculty of Materials Science and Technology, University of Science, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Vietnam; Vietnam National University, Ho Chi Minh City (VNU-HCM) 700000, Vietnam, Tran Cong Khanh ,   Faculty of Materials Science and Technology, University of Science, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Vietnam; Vietnam National University, Ho Chi Minh City (VNU-HCM) 700000, Vietnam, Nguyen Ngoc Phuong ,   Institute of Applied Materials Science, Vietnam Academy of Science and Technology (VAST), 29TL Street, Thanh Loc Ward, District 12, Ho Chi Minh City, Vietnam; Graduate University of Science and Technology, VAST, Hoang Quoc Viet Street, Cau Giay, Ha Noi, Vietnam, Dang Vinh Quang ,   Faculty of Materials Science and Technology, University of Science, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City 700000, Vietnam; Vietnam National University, Ho Chi Minh City (VNU-HCM) 700000, Vietnam
Published: April 2024

Introduction: Silver nanoparticles (Ag NPs) are pivotal in advancing surface-enhanced Raman scattering (SERS) due to their exceptional plasmonic properties. Yet, conventional synthesis methods often fail to precisely control their shape and size, impacting SERS efficiency. This study introduces a novel synthesis approach using hydrogen peroxide (H2O2) to tailor Ag NP morphologies, aiming to optimize their plasmonic resonance for improved SERS detection of hazardous substances.

Methods: We utilized a chemical reduction process with H2O2 to etch and shape Ag NPs, adjusting H2O2 concentrations to control nanoparticle morphology. The characterization of the nanoparticles involved SEM, TEM, and XRD for morphology and structure, with UV-Vis spectroscopy determining their absorption spectra.

Results: The approach yielded Ag NPs with variable shapes and absorption wavelengths (330 nm to 740 nm), directly correlating H2O2 concentration with morphological changes. SEM and TEM showed diverse nanoparticle shapes, and XRD confirmed their crystalline structure. Notably, nanoparticles tuned to specific absorption wavelengths significantly enhanced SERS detection of Rhodamine B.

Conclusion: Our method effectively produces multi-shaped Ag NPs with tunable optical properties, enhancing SERS application in detecting trace organic compounds. This streamlined synthesis process offers new possibilities for environmental monitoring and safety assessments.