title: Direct immobilisation of DNA probes for the development of affinity biosensors.
abstract: An immobilisation procedure based on the direct coupling of thiolated probes (Probe-C6-SH) to bare gold sensor surfaces has been compared with a reference immobilisation method, based on the coupling of biotinylated probes onto a streptavidin-coated dextran-modified surface. The instrumentations used were a quartz crystal microbalance (QCM) and the optical instruments Biacore X and Spreeta based on surface plasmon resonance (SPR). The performances of the DNA-based sensors resulting from direct coupling of thiolated DNA probes onto electrodes of quartz crystals or gold SPR-chips have been studied in terms of the main analytical parameters, i.e. selectivity, sensitivity, reproducibility, etc. In particular, the two immobilisation approaches have been applied to the analysis of oligonucleotides, DNA amplified by polymerase chain reaction (PCR) and genomic DNA enzymatically digested.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Firenze, Polo Scientifico, Via della Lastruccia 3, Sesto Fiorentino 50019, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Mannelli
authors.forename: Maria
authors.initials: M
authors.lastname: Minunni
authors.forename: Sara
authors.initials: S
authors.lastname: Tombelli
authors.forename: Ronghui
authors.initials: R
authors.lastname: Wang
authors.forename: Maria
authors.initials: M
authors.lastname: Michela Spiriti
authors.forename: Marco
authors.initials: M
authors.lastname: Mascini
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D019921:Biotinylation; D002417:Cattle; D015342:DNA Probes / Q000737:chemistry*; D016678:Genome; D009693:Nucleic Acid Hybridization / Q000379:methods; D009841:Oligonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D020349:Surface Plasmon Resonance
chemical_list: D015342:DNA Probes; D009841:Oligonucleotides