Printed platforms for paper-based analytical applications

G5 Doctoral dissertation (article)


Internal Authors/Editors


Publication Details

List of Authors: Anni Määttänen
Publisher: Painosalama Oy
Place: Turku
Publication year: 2014
ISBN: 978-952-12-3119-3


Abstract

Paper-based analytical technologies enable quantitative and rapid analysis
of analytes from various application areas including healthcare,
environmental monitoring and food safety. Because paper is a planar,
flexible and light weight substrate, the devices can be transported and
disposed easily. Diagnostic devices are especially valuable in resourcelimited
environments where diagnosis as well as monitoring of therapy
can be made even without electricity by using e.g. colorimetric assays. On
the other hand, platforms including printed electrodes can be coupled with
hand-held readers. They enable electrochemical detection with improved
reliability, sensitivity and selectivity compared with colorimetric assays.
In this thesis, different roll-to-roll compatible printing technologies were
utilized for the fabrication of low-cost paper-based sensor platforms.
The platforms intended for colorimetric assays and microfluidics were
fabricated by patterning the paper substrates with hydrophobic vinyl
substituted polydimethylsiloxane (PDMS) -based ink. Depending on the
barrier properties of the substrate, the ink either penetrates into the paper
structure creating e.g. microfluidic channel structures or remains on the
surface creating a 2D analog of a microplate. The printed PDMS can be
cured by a roll-ro-roll compatible infrared (IR) sintering method. The
performance of these platforms was studied by printing glucose oxidase
-based ink on the PDMS-free reaction areas. The subsequent application
of the glucose analyte changed the colour of the white reaction area to
purple with the colour density and intensity depending on the
concentration of the glucose solution.
Printed electrochemical cell platforms were fabricated on paper substrates
with appropriate barrier properties by inkjet-printing metal nanoparticle
based inks and by IR sintering them into conducting electrodes. Printed
PDMS arrays were used for directing the liquid analyte onto the
predetermined spots on the electrodes. Various electrochemical
measurements were carried out both with the bare electrodes and
electrodes functionalized with e.g. self assembled monolayers.
Electrochemical glucose sensor was selected as a proof-of-concept device
to demonstrate the potential of the printed electronic platforms.


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