Mannelli Ilaria, Minunni Maria, Tombelli Sara, Mascini Marco
Dipartimento di Chimica, Università degli Studi di Firenze, Polo Scientifico-Via della Lastruccia 3, Sesto Fiorentino-Florence 50019, Italy.
Biosens Bioelectron. 2003 Mar;18(2-3):129-40. doi: 10.1016/s0956-5663(02)00166-5.
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.
一种用于检测转基因生物（GMOs）的DNA压电传感器已被开发出来。单链DNA（ssDNA）探针被固定在石英晶体微天平（QCM）装置的传感器表面，并监测固定探针与溶液中目标互补序列之间的杂交情况。探针序列位于35S启动子（P）和Nos终止子（T）序列内部，35S启动子和Nos终止子是转基因生物基因组中调节转基因表达的插入序列。应用了两种不同的探针固定程序：（a）硫醇-葡聚糖程序和（b）硫醇衍生化探针和封闭硫醇程序。该系统已使用合成寡核苷酸进行了优化，然后应用于从pBI121质粒分离的质粒和基因组DNA样本、认证参考物质（CRM）以及通过聚合酶链反应（PCR）扩增的实际样本。研究了传感器的分析参数（灵敏度、重现性、寿命等）。获得的结果表明，两种固定程序都能灵敏且特异性地检测转基因生物，为食品样本的筛选分析提供了一种有用的工具。
