title: Quartz crystal microbalance (QCM) affinity biosensor for genetically modified organisms (GMOs) detection.
abstract: A DNA piezoelectric sensor has been developed for the detection of genetically modified organisms (GMOs). Single stranded DNA (ssDNA) probes were immobilised on the sensor surface of a quartz crystal microbalance (QCM) device and the hybridisation between the immobilised probe and the target complementary sequence in solution was monitored. The probe sequences were internal to the sequence of the 35S promoter (P) and Nos terminator (T), which are inserted sequences in the genome of GMOs regulating the transgene expression. Two different probe immobilisation procedures were applied: (a) a thiol-dextran procedure and (b) a thiol-derivatised probe and blocking thiol procedure. The system has been optimised using synthetic oligonucleotides, which were then applied to samples of plasmidic and genomic DNA isolated from the pBI121 plasmid, certified reference materials (CRM), and real samples amplified by the polymerase chain reaction (PCR). The analytical parameters of the sensor have been investigated (sensitivity, reproducibility, lifetime etc.). The results obtained showed that both immobilisation procedures enabled sensitive and specific detection of GMOs, providing a useful tool for screening analysis in food samples.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Firenze, Polo Scientifico-Via della Lastruccia 3, Sesto Fiorentino-Florence 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: Marco
authors.initials: M
authors.lastname: Mascini
mesh_terms: D000345:Affinity Labels; D016960:Agrobacterium tumefaciens / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D017796:Caulimovirus / Q000235:genetics; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis; D003460:Crystallization / Q000295:instrumentation / Q000379:methods; D004247:DNA / Q000032:analysis* / Q000592:standards; D015342:DNA Probes; D004275:DNA, Ribosomal / Q000032:analysis; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D005506:Food Contamination / Q000032:analysis; D008839:Microelectrodes; D030781:Organisms, Genetically Modified / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D011786:Quality Control; D011791:Quartz; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers
chemical_list: D000345:Affinity Labels; D020099:Coated Materials, Biocompatible; D015342:DNA Probes; D004275:DNA, Ribosomal; D011791:Quartz; D004247:DNA