title: Discriminating DNA mismatches by electrochemical and gravimetric techniques.
abstract: A silicon nitride functionalized electrode and a 104 MHz lithium tantalate (LiTaO₃) surface acoustic wave (SAW) sensor have been used to investigate target-probe recognition processes. Electrochemical and gravimetric measurements have been considered to monitor hybridization of single base mismatch (SBM) in synthetic oligonucleotides and single-nucleotide polymorphisms ApoE in real clinical genotypes. Obvious discrimination of SBM in nucleotides has been shown by both gravimetric and electrochemical techniques, without labeling nor amplification. Investigations on mismatches nature and position have also been considered. For guanine-adenine (GA), guanine-thymine (GT) and guanine-guanine (GG) mismatches, the sensors responses present a dependence upon positions. Considering the capacitance variations and hybridization rates, results showed that gravimetric transduction is more sensitive than electrochemical one. Moreover, the highest value of GT hybridization rate (in the middle position) was found in accordance with the nearest-neighbor model, where the considered configuration appears as the most thermodynamically stable. For the real samples, where the electrochemical transduction, by combining capacitance and flat-band potential measurements, were found more sensitive, the results show that the realized sensor permits an unambiguous discrimination of recognition between fully complementary, non-complementary and single base mismatched targets, and even between the combination of differently matched strands.
authors.affiliation: Laboratoire Méthodes et Techniques d'Analyse, INRAP, BiotechPole, 2020 Sidi-Thabet, Tunisia. zouhour_2004@yahoo.fr
authors.forename: Zouhour
authors.initials: Z
authors.lastname: Mazouz
authors.forename: Najla
authors.initials: N
authors.lastname: Fourati
authors.forename: Chouki
authors.initials: C
authors.lastname: Zerrouki
authors.forename: Asma
authors.initials: A
authors.lastname: Ommezine
authors.forename: Lamia
authors.initials: L
authors.lastname: Rebhi
authors.forename: Nourdin
authors.initials: N
authors.lastname: Yaakoubi
authors.forename: Rafik
authors.initials: R
authors.lastname: Kalfat
authors.forename: Ali
authors.initials: A
authors.lastname: Othmane
mesh_terms: D001057:Apolipoproteins E / Q000235:genetics*; D020137:Base Pair Mismatch; D015374:Biosensing Techniques / Q000379:methods; D004247:DNA / Q000235:genetics*; D055664:Electrochemical Techniques / Q000379:methods*; D006112:Gravitation; D006801:Humans; D020641:Polymorphism, Single Nucleotide
chemical_list: D001057:Apolipoproteins E; D004247:DNA