Scientific Results

Fiber-cap biosensors for SERS analysis of liquid samples

Year: 2020

Authors: Credi Caterina; Bibikova Olga; Dallari Caterina; Tiribilli Bruno; Ratto Fulvio; Centi Sonia; Pini Roberto; Artyushenko Viacheslav; Cicchi Riccardo; Pavone,Francesco Saverio

Autors Affiliation: European Lab Nonlinear Spect, LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; Univ Florence, Dept Informat Engn, Via S Marta 3, I-50139 Florence, Italy; Art Photon GmbH, Rudower Chaussee 46, D-12489 Berlin, Germany; CNR, Natl Res Council, ISC, Inst Complex Syst, Via Madonna Piano 10, I-50019 Sesto Fiorentino, Italy; CNR, Natl Res Council, Inst Appl Phys N Carrara, IFAC, Via Madonna Piano 10, I-50019 Sesto Fiorentino, Italy; CNR, Natl Res Council, Natl Inst Opt, INO, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; Univ Florence, Dept Phys, Via G Sansone 1, I-50019 Sesto Fiorentino, Italy

Abstract: Optical detection techniques based on surface enhanced Raman spectroscopy (SERS) are a powerful tool for biosensing applications. Meanwhile, due to technological advances, different approaches have been investigated to integrate SERS substrates on the tip of optical fibres for molecular probing in liquids. To further demonstrate the perspectives offered by SERS-on-fiber technology for diagnostic purposes, in this study, novel cap-shaped SERS sensors for reversible coupling with customized multimodal probes were prototyped via low-cost polymer casting of polydimethylsiloxane (PDMS) and further assembly of gold nanoparticles (Au NPs) of varied sizes and shapes. To demonstrate the feasibility of liquid sensing with cap sensors using backside illumination and detection, the spectra of rhodamine were acquired by coupling the caps with the fiber. As expected by UV-vis, the highest SERS efficiency was observed for NP-decorated substrates with plasmonic properties in resonance with the irradiation wavelength. Then, SERS biosensors for the specific detection of amyloid-beta (A beta) neurotoxic biomarkers were realized by covalent grafting of A beta antibodies. As attested by fluorescence images and SERS measurements, the biosensors successfully exhibited enhanced A beta affinity compared to the bare sensors without ligands. Finally, these versatile (bio)sensors are a powerful tool to transform any milli-sized fibers into functional (bio)sensing platforms with plasmonic and biochemical properties tailored for specific applications.

Journal/Review: JOURNAL OF MATERIALS CHEMISTRY B

Volume: 8 (8)      Pages from: 1629  to: 1639

KeyWords: enhanced Raman-scattering; amyloid-beta-peptide; gold nanorods; tip; nanoparticles; spectroscopy; trasparent; bacteria; platform; arrays
DOI: 10.1039/c9tb01866b

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