Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Biomedical Research Center, Carle Foundation Hospital, Urbana, IL, USA.
Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Biomedical Research Center, Carle Foundation Hospital, Urbana, IL, USA.
Biosens Bioelectron. 2018 Jul 1;110:132-140. doi: 10.1016/j.bios.2018.03.044. Epub 2018 Mar 23.
Although significant technological advancements have been made in the development of analytical biosensor chips for detecting bacterial strains (E. coli, S. Mutans and B. Subtilis), critical requirements i.e. limit of detection (LOD), fast time of response, ultra-sensitivity with high reproducibility and good shelf-life with robust sensing capability have yet to be met within a single sensor chip. In order to achieve these criteria, we present an electrically-receptive thermally-responsive (ER-TR) sensor chip comprised of simple filter paper used as substrate coated with composite of poly(N-isopropylacrylamide) polymer (PNIPAm) - graphene nanoplatelet (GR) followed by evaporation of Au electrodes for capturing both Gram-positive (S. mutans and B. subtilis) and Gram-negative (E. coli) bacterial cells in real-time. Autoclave water, tap water, lake water and milk samples were tested with ER-TR chip with and without bacterial strains at varying concentration range 10-10 cells/mL. The sensor was integrated with in-house built printed circuit board (PCB) to transmit/receive electrical signals. The interaction of E. coli, S. mutans and B. subtilis cells with fibers of PNIPAm-GR resulted in a change of electrical resistance and the readout was monitored wirelessly in real-time using MATLAB algorithm. Finally, prepared ER-TR chip exhibited the reproducibility of 85-97% with shelf-life of up to four weeks after testing with lake water sample.
尽管在开发用于检测细菌菌株(大肠杆菌、变形链球菌和枯草芽孢杆菌)的分析生物传感器芯片方面取得了重大技术进步,但在单个传感器芯片中仍未满足关键要求,即检测限(LOD)、快速响应时间、超高灵敏度和高重现性以及具有稳健感测能力的良好保质期。为了实现这些标准,我们提出了一种电响应热响应(ER-TR)传感器芯片,该芯片由简单的滤纸作为基底,涂有聚(N-异丙基丙烯酰胺)聚合物(PNIPAm)-石墨烯纳米片(GR)的复合材料,然后蒸发金电极用于实时捕获革兰氏阳性(变形链球菌和枯草芽孢杆菌)和革兰氏阴性(大肠杆菌)细菌细胞。对自来水电导率、自来水、湖水和牛奶样品进行了测试,带有和不带有不同浓度范围为 10-10 个细胞/mL 的细菌菌株的 ER-TR 芯片。传感器与内部构建的印刷电路板(PCB)集成,用于传输/接收电信号。大肠杆菌、变形链球菌和枯草芽孢杆菌细胞与 PNIPAm-GR 纤维的相互作用导致电阻变化,并使用 MATLAB 算法实时无线监测读数。最后,在对湖水样本进行测试后,制备的 ER-TR 芯片表现出 85-97%的重现性和长达四周的保质期。