School of Chemical and Biomolecular Sciences, Southern Illinois University, 1245 Lincoln Drive, Carbondale, IL 62918, USA.
School of Physics and Applied Physics, Southern Illinois University, Carbondale, IL 62918, USA.
Biosensors (Basel). 2021 Aug 14;11(8):273. doi: 10.3390/bios11080273.
DNA is strongly adsorbed on oxidized graphene surfaces in the presence of divalent cations. Here, we studied the effect of DNA adsorption on electrochemical charge transfer at few-layered, oxygen-functionalized graphene (GO) electrodes. DNA adsorption on the inkjet-printed GO electrodes caused amplified current response from ferro/ferricyanide redox probe at concentration range 1 aM-10 nM in differential pulse voltammetry. We studied a number of variables that may affect the current response of the interface: sequence type, conformation, concentration, length, and ionic strength. Later, we showed a proof-of-concept DNA biosensing application, which is free from chemical immobilization of the probe and sensitive at attomolar concentration regime. We propose that GO electrodes promise a low-cost solution to fabricate a highly sensitive platform for label-free and chemisorption-free DNA biosensing.
DNA 在二价阳离子存在的情况下会被强烈吸附在氧化石墨烯表面。在这里，我们研究了 DNA 吸附对喷墨打印的含氧官能化石墨烯 (GO) 电极的电化学电荷转移的影响。在差分脉冲伏安法中，DNA 在 GO 电极上的吸附引起了铁/亚铁氰化物氧化还原探针在 1 aM-10 nM 浓度范围内的电流响应放大。我们研究了许多可能影响界面电流响应的变量：序列类型、构象、浓度、长度和离子强度。之后，我们展示了一个 DNA 生物传感应用的概念验证，该应用无需探针的化学固定，在纳摩尔浓度范围内具有较高的灵敏度。我们提出 GO 电极有望成为一种低成本的解决方案，用于制造无需标记和化学吸附的高灵敏度 DNA 生物传感平台。
