Share Email Print
cover

Proceedings Paper

A SERS affinity bioassay based on ion-exchanged glass microrods (Conference Presentation)

Paper Abstract

The well-known enhancement effect of surface-enhanced Raman spectroscopy (SERS) is associated with the presence of metallic nanostructures at the substrate surface. Different bottom-up and top-down processes have been proposed to impart the substrate with such a nanostructured layer. The former approaches are low cost but may suffer from reusability and stability. The latter strategies are expensive, time consuming and require special equipment that complicate the fabrication process. Here, we present the possibility to obtain stable and reusable SERS substrates by a low-cost silver-sodium ion-exchange process in soda-lime glass microrods. The microrods were obtained by cutting the tip of the ion-exchanged soda-lime fiber, resulting in disks of about few millimeters in length and one hundred microns in diameter. A thermal annealing post-process was applied to trigger the reduction of Ag+ ions into nanoparticles (AgNPs) within the ion-exchanged glass microrods. Afterwards, ion-exchange and thermal treatments were carefully tuned to assure the presence of silver NPs exposed on the surface of the microrods, without using any chemical etching. An AFM analysis confirmed the presence of AgNPs with size of tens of nm on the surface of the fiber probe. A SERS affinity bioassay was developed on the probe with the final aim of detecting microRNA fragments acting as biomarkers of different diseases. Specifically a DNA hybridization assay was built up by anchoring a molecular beacon containing a Raman tag on the Ag surface via thiol chemistry. Initial SERS experiments confirmed the presence of the beacon on the NPs embedded on the microrods surface, as monitored by detecting main spectral bands ascribed to the oligonucleotide chain. Finally, the ability of the platform to interact with the target microRNA sequence was assessed. The analysis was repeated on a number of miRNA sequences differing from the target to evaluate the specificity of the proposed assay.

Paper Details

Date Published: 1 April 2020
PDF
Proc. SPIE 11361, Biophotonics in Point-of-Care, 113610V (1 April 2020); doi: 10.1117/12.2555817
Show Author Affiliations
Simone Berneschi, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)
Cristiano D'Andrea, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)
Ambra Giannetti, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)
Marella De Angelis, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)
Martina Banchelli, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)
Andrea Barucci, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)
Nadia Giovanna Boetti, Istituto Superiore Mario Boella (Italy)
Stefano Pelli, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)
Museo Storico della Fisica e Ctr. Studi e Ricerche "Enrico Fermi" (Italy)
Francesco Baldini, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)
Roberto Pini, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)
Davide Janner, Politecnico di Torino (Italy)
Diego Pugliese, Politecnico di Torino (Italy)
Daniel Milanese, Politecnico di Torino (Italy)
CNR-Istituto di Fotonica e Nanotecnologie (Italy)
Univ. degli Studi di Parma (Italy)
Paolo Matteini, Istituto di Fisica Applicata "Nello Carrara", Consiglio Nazionale delle Ricerche (Italy)


Published in SPIE Proceedings Vol. 11361:
Biophotonics in Point-of-Care
Michael T. Canva; Ambra Giannetti; Hatice Altug; Julien Moreau, Editor(s)

© SPIE. Terms of Use
Back to Top
PREMIUM CONTENT
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?
close_icon_gray