Fiber-Based SERS-Fluidic Polymeric Platforms for Improved Optical Analysis of Liquids

Year: 2023

Authors: Credi C., Dallari C., Nocentini S., Gatta G., Bianchi E., Wiersma DS., Pavone FS.

Autors Affiliation: European Lab Nonlinear Spect LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; Natl Res Council INO CNR, Natl Inst Opt, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; Univ Florence, Dept Phys, Via G Sansone 1, I-50019 Sesto Fiorentino, Italy; Natl Inst Metrol INRiM, I-10135 Turin, Italy; Politecn Milan, Dept Chem Mat & Chem Engn, Piazza Leonardo da Vinci 32, I-20133 Milan, Italy.

Abstract: Downsizing surface-enhanced Raman spectroscopy (SERS) within microfluidic devices has opened interesting perspectives for the development of low-cost and portable (bio)sensors for the optical analysis of liquid samples. Despite the research efforts, SERS-fluidic devices still rely either on the use of expensive bulky set-ups or on polymeric devices giving spurious background signals fabricated via expensive manufacturing processes. Here, polymeric platforms integrating fluidics and optics were fabricated with versatile designs allowing easy coupling with fiber-based Raman systems. For the first time, anti-fouling photocurable perfluoropolyether (PFPE) was explored for high-throughput SERS-integrating chip fabrication via replica molding of negative stamps obtained through standard and advanced fabrication processes. The PFPE devices comprised networks of channels for fluid handling and for optical fiber housing with multiple orientations. Embedded microfeatures were used to control the relative positioning of the fibers, thus guaranteeing the highest signal delivering and collection. The feasibility of PFPE devices as fiber-based SERS fluidic platforms was demonstrated through the straightforward acquisition of Raman-SERS spectra of a mixture of gold nanoparticles as SERS substrates with rhodamine 6G (Rh6G) at decreasing concentrations. In the presence of high-performing gold nanostars, the Rh6G signal was detectable at dilutions down to the nanomolar level even without tight focusing and working at low laser power-a key aspect for analyte detection in real-world biomedical and environmental applications.

Journal/Review: Bioengineering-Basel

Volume: 10 (6)      Pages from: 676-1  to: 676-14

More Information: This work was supported by the DoptoScreen project financed by the Italian private foundation Fondo di Beneficenza Intesa San Paolo 2019 -grant number B/2019/0289. The APC was funded by the National project Advanced Light Microscopy Italian Node-ERIC EuroBioimaging.
KeyWords: surface-enhanced Raman spectroscopy (SERS); nanoparticles; microfluidics; 3D printing; lab-on-chip (LOC); liquid samples; photocurable perfluoropolyethers
DOI: 10.3390/bioengineering10060676

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