Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

There will be scheduled maintenance work beginning on Saturday 15th June 2019 at 8:30 am through to Sunday 16th June 2019 at 11:30 pm (BST).

During this time our website may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.

Volume 205, 2017
Previous Article Next Article

SERS-active metal-dielectric nanostructures integrated in microfluidic devices for label-free quantitative detection of miRNA

Author affiliations


In this work, SERS-based microfluidic PDMS chips integrating silver-coated porous silicon membranes were used for the detection and quantitation of microRNAs (miRNAs), which consist of short regulatory non-coding RNA sequences typically over- or under-expressed in connection with several diseases such as oncogenesis. In detail, metal–dielectric nanostructures which provide noticeable Raman enhancements were functionalized according to a biological protocol, adapted and optimized from an enzyme-linked immunosorbent assay (ELISA), for the detection of miR-222. Two sets of experiments based on different approaches were designed and performed, yielding a critical comparison. In the first one, the labelled target miRNA is revealed through hybridization to a complementary thiolated DNA probe, immobilized on the silver nanoparticles. In the second one, the probe is halved into shorter strands (half1 and half2) that interact with the complementary miRNA in two steps of hybridization. Such an approach, taking advantage of the Raman labelling of half2, provides a label-free analysis of the target. After suitable optimisation of the procedures, two calibration curves allowing quantitative measurements were obtained and compared on the basis of the SERS maps acquired on the samples loaded with several miRNA concentrations. The selectivity of the two-step assay was confirmed by the detection of target miR-222 mixed with different synthetic oligos, simulating the hybridization interference coming from similar sequences in real biological samples. Finally, that protocol was applied to the analysis of miR-222 in cellular extracts using an optofluidic multichamber biosensor, confirming the potentialities of SERS-based microfluidics for early-cancer diagnosis.

Back to tab navigation

Supplementary files

Publication details

The article was received on 21 Apr 2017, accepted on 04 May 2017 and first published on 09 May 2017

Article type: Paper
DOI: 10.1039/C7FD00140A
Faraday Discuss., 2017,205, 271-289

  •   Request permissions

    SERS-active metal-dielectric nanostructures integrated in microfluidic devices for label-free quantitative detection of miRNA

    C. Novara, A. Chiadò, N. Paccotti, S. Catuogno, C. L. Esposito, G. Condorelli, V. De Franciscis, F. Geobaldo, P. Rivolo and F. Giorgis, Faraday Discuss., 2017, 205, 271
    DOI: 10.1039/C7FD00140A

Search articles by author