Scalable synthesis of self-assembled magneto-plasmonic core-satellite nanoparticles for microfluidic sorting and bioorthogonal sensing of targeted cells
Year: 2025
Authors: Mattii F., Feregotto G., Muzzi B., Pavone F.S., Calamai M., Capitini C., Dallari C., Credi C.
Autors Affiliation: European Lab Nonlinear Spect LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, FI, Italy; CNR, Natl Inst Opt INO, Via Nello Carrara 1, I-50019 Sesto Fiorentino, FI, Italy; CNR, Inst Chem Organometall Cpds ICCOM, Via Madonna Piano 10, I-50019 Sesto Fiorentino, FI, Italy; Univ Florence, Dept Chem Ugo Schiff, I-50019 Sesto Fiorentino, FI, Italy; Univ Florence, INSTM, I-50019 Sesto Fiorentino, FI, Italy; Univ Florence, Dept Phys & Astron, Via G Sansone 1, I-50019 Sesto Fiorentino, FI, Italy.
Abstract: Multifunctional magneto-plasmonic nanoparticles (MP-NPs) are attracting increasing interest for biomedical applications due to their dual magnetic and optical properties. However, existing synthesis protocols for MP-NPs could be limited by harsh conditions or lengthy, complex procedures. These limitations can hinder the development of nanosystems that work effectively in biological dispersion. In this work, we present a flexible nanoplatform for capture and probe applications, based on MP-NPs and bioorthogonal plasmonic nanoparticles (AuNPs). This system enables efficient cell sorting and surface-enhanced Raman scattering (SERS) detection in complex biological media under dynamic conditions. Magnetic Fe3O4 nanoclusters were synthesized using a scalable, aqueous Massart-based protocol. These structures were then densely decorated with electrostatically assembled AuNPs, producing magnetically responsive and plasmonically active nanocomposites with high aqueous stability. A polyethylene glycol (PEG) derivative was used for surface functionalization, improving colloidal stability and enabling broad bio-recognition capability. To enhance detection sensitivity and shift the optical response into the near-infrared (NIR) range, bioorthogonal Raman-active gold nanostars (AuNSts) were integrated into a sandwich configuration with the MP-NPs. The system demonstrated selective sorting and sensitive SERS-based identification of cell subpopulation within a heterogeneous sample. Additionally, the integration of the MP-NPs assay into a 3D-printed microfluidic device allowed controlled nanoparticles manipulation using external magnets, enhancing magnetic separation, hot-spots generation, and assay reusability. Overall, these MP-NPs platform combines scalable synthesis, tunable colloidal and surface properties, and compatibility with microfluidic systems. This work lays the foundation for advanced biosensing approaches in lab-on-chip formats for clinical diagnostics and targeted analysis of rare cell populations.
Journal/Review: COLLOIDS AND SURFACES B-BIOINTERFACES
Volume: 256 Pages from: 115040-1 to: 115040-11
More Information: Financial support was provided by CNR-FOE-LENS-2023, by the Integrated infrastructure initiative in photonic and quantum sciences I-PHOQS (CUP B53C22001750006) project and by the Fluorinated hybrid Photopolymers for the fabrication of robust optofluidic devices-OPTO-19F-LUIDIC (CUP B53D23015530006) PRIN project financed by the EU next generation PNRR action, by the Italian Ministry of Education, University and Research in the framework of PNRR projects AGE-IT Ageing well in an ageing society and in the framework of the Advance Lightsheet Microscopy Italian Mode of Euro-bioimaging ERIC. The authors would also like to thank the Centre for Electron Micros-copies (Ce.ME) and the Centro di competenza RISE funded by FAS Regione Toscana.KeyWords: Magneto-plasmonic nanoparticles; Gold nanostars; SERS; Bioorthogonal Raman; Cell sorting; 3D printing; Microfluidic assayDOI: 10.1016/j.colsurfb.2025.115040
