Multiwavelength SERS of Magneto-Plasmonic Nanoparticles Obtained by Combined Laser Ablation and Solvothermal Methods

Martynas Talaikis; Lina Mikoliunaite; Aikaterini-Maria Gkouzi; Vita Petrikaitė; Evaldas Stankevičius; Audrius Drabavičius; Algirdas Selskis; Remigijus Juškėnas; Gediminas Niaura

doi:10.1021/acsomega.3c08007

Multiwavelength SERS of Magneto-Plasmonic Nanoparticles Obtained by Combined Laser Ablation and Solvothermal Methods

ACS Omega. 2023 Dec 14;8(51):49396-49405. doi: 10.1021/acsomega.3c08007. eCollection 2023 Dec 26.

Authors

Martynas Talaikis¹, Lina Mikoliunaite^{1

2}, Aikaterini-Maria Gkouzi¹, Vita Petrikaitė³, Evaldas Stankevičius³, Audrius Drabavičius⁴, Algirdas Selskis⁴, Remigijus Juškėnas⁴, Gediminas Niaura¹

Affiliations

¹ Department of Organic Chemistry, Center for Physical Sciences and Technology (FTMC), Saulėtekio Av. 3, LT-10257 Vilnius, Lithuania.
² Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko Str. 24, LT-03225 Vilnius, Lithuania.
³ Department of Laser Technologies, Center for Physical Sciences and Technology (FTMC), Savanorių Av. 231, LT-02300 Vilnius, Lithuania.
⁴ Department of Characterization of Materials Structure, Center for Physical Sciences and Technology (FTMC), Saulėtekio Av. 3, LT-10257 Vilnius, Lithuania.

Abstract

The present study introduces a novel method for the synthesis of magneto-plasmonic nanoparticles (MPNPs) with enhanced functionality for surface-enhanced Raman scattering (SERS) applications. By employing pulsed laser ablation in liquid (PLAL) to synthesize plasmonic nanoparticles and wet chemistry to synthesize magnetic nanoparticles, we successfully fabricated chemically pure hybrid Fe₃O₄@Au and Fe₃O₄@Ag nanoparticles. We demonstrated a straightforward approach of an electrostatic attachment of the plasmonic and magnetic parts using positively charged polyethylenimine. The MPNPs displayed high SERS sensitivity and reproducibility, and the magnetic part allowed for the controlled separation of the nanoparticles from the reaction mixture, their subsequent concentration, and their precise deposition onto a specified surface area. Additionally, we fabricated alloy based MPNPs from Ag_xAu_100-x (x = 50 and 80 wt %) targets with distinct localized surface plasmon resonance (LSPR) wavelengths. The compositions, morphologies, and optical properties of the nanoparticles were characterized by using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-vis spectroscopy, and multiwavelength Raman spectroscopy. A standard SERS marker, 4-mercaptobenzoic acid (4-MBA), validated the enhancement properties of the MPNPs and found an enhancement factor of 2 × 10⁸ for the Fe₃O₄@Ag nanoparticles at 633 nm excitation. Lastly, we applied MPNP-enhanced Raman spectroscopy for the analysis of the biologically relevant molecule adenine and found a limit of detection of 10^-7 M at 785 nm excitation. The integration of PLAL and wet chemical methods enabled the relatively fast and cost-effective production of MPNPs characterized by high SERS sensitivity and signal reproducibility that are required in various fields, including biomedicine, food safety, materials science, security, and defense.