Department of Chemistry, State University of New York at Potsdam, Potsdam, NY 13676, USA.
Biosens Bioelectron. 2011 Apr 15;26(8):3524-30. doi: 10.1016/j.bios.2011.01.038. Epub 2011 Mar 3.
The influence of potential barriers, introduced to the immunoglobulin-based sensory films, on voltammetric signals of a redox ion probe has been investigated. Films with positive and negative barriers have been examined by depositing charged self-assembled thiol monolayers as the basal layers of a sensory film. The studies performed with monoclonal anti-glutathione antibody-based sensors using ferricyanide ion probe have shown stronger sensor response to the layer components, as well as to the glutathione-capped gold nanoparticles acting as the antigen, for films with positive potential barrier buried deep in the film than for negative barrier films. The larger changes in differential resistance, peak separation and peak heights observed for films with positive barrier have been attributed to different depth and width of the charge distributions in these films. A buried positive barrier with narrow charge distribution width provides the best conditions for film stability and prevents fouling (less ion-exchanges with the medium). This conclusion has been confirmed by calculations of the electric field distribution and potential profiles in immunosensing films performed by numerical integration of Poisson equation for Gaussian distributions of fixed charges of covalently bound components. The proposed fixed-charge model can aid in rapid evaluation of sensory films in sensor development work. The implications of potential barriers in sensory film design are discussed.
研究了在基于免疫球蛋白的敏感膜中引入的势垒对氧化还原离子探针伏安信号的影响。通过沉积带电荷的自组装硫醇单层作为敏感膜的基底层，研究了具有正势垒和负势垒的薄膜。使用基于单克隆抗谷胱甘肽抗体的传感器，用铁氰化钾离子探针进行的研究表明，对于正势垒埋深深在膜中的薄膜，传感器对层组件以及作为抗原的金纳米粒子的谷胱甘肽封端的响应更强。与负势垒薄膜相比，对于具有正势垒的薄膜，观察到差分电阻、峰分离和峰高的更大变化归因于这些薄膜中电荷分布的不同深度和宽度。具有窄电荷分布宽度的埋置正势垒为膜稳定性提供了最佳条件，并防止了污垢（与介质的离子交换较少）。这一结论已通过数值积分泊松方程对于共价结合组分的固定电荷的高斯分布来计算免疫传感膜中的电场分布和电势分布得到证实。所提出的固定电荷模型可以帮助在传感器开发工作中快速评估敏感膜。讨论了势垒在敏感膜设计中的影响。
