Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology (IFM), Linkoping University, 58183 Linkoping, Sweden; Eletroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
Eletroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
Biosens Bioelectron. 2016 Jun 15;80:566-573. doi: 10.1016/j.bios.2016.02.024. Epub 2016 Feb 10.
Fast and accurate detection of microorganisms is of key importance in clinical analysis and in food and water quality monitoring. Salmonella typhimurium is responsible for about a third of all cases of foodborne diseases and consequently, its fast detection is of great importance for ensuring the safety of foodstuffs. We report the development of a label-free impedimetric aptamer-based biosensor for S. typhimurium detection. The aptamer biosensor was fabricated by grafting a diazonium-supporting layer onto screen-printed carbon electrodes (SPEs), via electrochemical or chemical approaches, followed by chemical immobilisation of aminated-aptamer. FTIR-ATR, contact angle and electrochemical measurements were used to monitor the fabrication process. Results showed that electrochemical immobilisation of the diazonium-grafting layer allowed the formation of a denser aptamer layer, which resulted in higher sensitivity. The developed aptamer-biosensor responded linearly, on a logarithm scale, over the concentration range 1 × 10(1) to 1 × 10(8)CFU mL(-1), with a limit of quantification (LOQ) of 1 × 10(1) CFU mL(-1) and a limit of detection (LOD) of 6 CFU mL(-1). Selectivity studies showed that the aptamer biosensor could discriminate S. typhimurium from 6 other model bacteria strains. Finally, recovery studies demonstrated its suitability for the detection of S. typhimurium in spiked (1 × 10(2), 1 × 10(4) and 1 × 10(6) CFU mL(-1)) apple juice samples.
快速准确地检测微生物在临床分析以及食品和水质监测中至关重要。鼠伤寒沙门氏菌是导致约三分之一食源性疾病的罪魁祸首，因此，快速检测它对于确保食品的安全非常重要。我们报告了一种无标记的基于适配体的阻抗生物传感器的开发，用于检测鼠伤寒沙门氏菌。通过电化学或化学方法，将支持叠氮化物的层接枝到丝网印刷碳电极（SPE）上，然后通过化学固定化氨化适配体，制备适配体生物传感器。傅里叶变换衰减全反射（FTIR-ATR）、接触角和电化学测量用于监测制备过程。结果表明，电化学固定化叠氮化物接枝层允许形成更密集的适配体层，从而提高了灵敏度。开发的适配体生物传感器在 1 × 10(1) 到 1 × 10(8) CFU mL(-1) 的浓度范围内呈对数线性响应，定量限（LOQ）为 1 × 10(1) CFU mL(-1)，检测限（LOD）为 6 CFU mL(-1)。选择性研究表明，适配体生物传感器能够区分鼠伤寒沙门氏菌和其他 6 种模式细菌株。最后，回收研究表明它适用于检测苹果汁中添加的鼠伤寒沙门氏菌（1 × 10(2)、1 × 10(4) 和 1 × 10(6) CFU mL(-1))。
Zotero 插件