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.com
Volume 7
Biosensors Journal
ISSN: 2090-4967
Electrochemistry 2018
June 11-12, 2018
June 11-12, 2018 | Rome, Italy
4
th
International Conference on
Electrochemistry
Electrochemical deposition of artificial recognition unit for gluten epitope selective determination
Zofia Iskierko
1
, Piyush S Sharma
2
, Alessandra Maria Bossi
1
and
Wlodzimierz Kutner
1, 3
1
University of Verona, Italy
Polish Academy of Sciences, Poland
3
Cardinal Stefan Wyszynski University in Warsaw, Poland
G
luten, which chemically corresponds to storage proteins deposited in the starchy endosperm cells of the developing grain,
is the allergen that triggers autoimmune reactions in people suffering from celiac sprue (CS). It is estimated that CS
affects 1-2% of the European population with direct healthcare costs estimated at about 3 bn EUR/year. The only effective
therapy is strict dietary abstinence from gluten. In fact, even a small contamination of food with gluten can cause serious
adverse reactions from digestive system. Food considered as gluten-free, thus safe for CS suffering people, should contain
less than 20 mg/kg of gluten. Molecularly imprinted polymers (MIPs) are artificially made receptors with the ability to bind
reversibly and therefore, to recognize the target analytes. The fabrication of MIPs against small molecules or peptides is now
straightforward whereas imprinting of large molecular structures, such as proteins, is still challenging. A possible solution is to
imprint just defined epitopes instead of the whole protein. In the present study, a toxic gluten epitope, PQQPFPQQ, was chosen
as a template for imprinting. The MIP film was prepared by electrochemical polymerization of bis(bithiophene) derivatives,
bearing either cytosine or carboxylic acid substituent, in the presence of the template and a cross-linker. After deposition, the
template was extracted from the polymer film. Subsequently, the film composition was characterized by x-ray photoelectron
spectroscopy (XPS) as well as its morphology and thickness was studied by atomic force microscopy (AFM). Performance of
this chemical sensor was tested under laboratory conditions. Extended-gate field-effect transistor (EG-FET) sensor signals
were measured for an aqueous solution of the PQQPFPQQ analyte, as well as its interferences with 1 or 2 mismatched amino
acids. Moreover, the sensor responses were measured toward the PQQPFPQQ analyte in gluten samples digested with pepsin
at pH ≈ 2. Finally, analytical parameters of the devised chemosensor were evaluated.
zofiaewa.iskierko@univr.itBiosens J 2018, Volume 7
DOI: 10.4172/2090-4967-C1-003