title: Towards a target label-free suboptimum oligonucleotide displacement-based detection system.
abstract: A novel method for the future development of label-free DNA sensors is proposed here. The approach is based on the displacement of a labelled suboptimum mutated oligonucleotide hybridised with the immobilised biotin-capture probe. The target fully complementary to the biotin-capture probe can displace the labelled oligonucleotide causing a subsequent decrease of the signal that verifies the presence of the target. The decrease of signal was demonstrated to be proportional to the target concentration. A study of the hybridisation of mutated and complementary labelled oligonucleotides with an immobilised biotin-capture probe was carried out. Different kinetic and thermodynamic behaviour was observed for heterogeneous hybridisation of biotin-capture probe with complementary or suboptimum oligonucleotides. The displacement method evaluated colourimetrically achieved the objective of decreasing the response time from 1 h for direct hybridisation of 19-mer oligonucleotides in the direct enzyme-linked oligonucleotide assay (ELONA) to 5 min in the case of displacement detection in the micromolar concentration range.
authors.affiliation: Bioengineering and Bioelectrochemistry Group, Departament d'Enginyeria Química, Escola Tècnica Superior d'Enginyeria Química, Universitat Rovira i Virgili, Avd. Països Catalans, 26, 43007, Tarragona, Spain. mir@mpip-mainz.mpg.de
authors.forename: Mònica
authors.initials: M
authors.lastname: Mir
authors.forename: Pablo
authors.initials: P
authors.lastname: Lozano-Sánchez
authors.forename: Ioanis
authors.initials: I
authors.lastname: Katakis
mesh_terms: D015374:Biosensing Techniques; D001710:Biotin; D003124:Colorimetry; D015336:Molecular Probe Techniques; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes
chemical_list: D015345:Oligonucleotide Probes; D001710:Biotin