Department of Chemistry, Razi University, Kermanshah, Iran.
Department of Chemistry, Razi University, Kermanshah, Iran.
Anal Chim Acta. 2019 May 9;1055:7-16. doi: 10.1016/j.aca.2018.12.013. Epub 2018 Dec 29.
This study introduces a signal amplification strategy rely on incorporating a specific polymer film between two typical nanostructured layers, aiming to improve the electrical properties of the platform to be able to transduce small binding event through sub-femtomolar detection of HIV-1 gene at the surface of the constructed biosensing device. The proposed composite was arrayed based on a conductive layer consist of p-aminobenzoic acid (PABA) sandwiched between the electrochemically reduced graphene oxide (ERGO) as the sub-layer, and the gold nanoparticles (AuNPs) as the interfacial layer. We computationally explored that how the use of such design enables the platform to transduce small changes in the interfacial properties of the biosensor, caused by low concentrations of HIV-1 gene, without needing any amplification strategy. Furthermore, it was found that the loin PABA conductive polymer sandwiched between two nanostructure layers play an artwork-ensemble role, which resulted in a good signal repeatability and stability during the relatively long successive incubation and detection procedures. The justification of using such an array of conductive layers was established on the attaining extra low-level of detection limit. The observed performance for probe-DNA immobilized on glassy carbon electrode (GC) modified with ERGO/PABA/AuNPs compared to the GC electrode modified with ERGO/AuNPs inspired us to perform computational calculations, a hybrid of ab-initio and semi-empirical quantum mechanics methods, to discover its probable molecular-scale reasons. A rapid single frequency impedance measurement (SFIM) was also employed to remarkably reduce the measurement time and diminish the probable nonspecific impedance changes. The proposed biosensor was used to evaluate the DNA target over an extremely wide concentration range from 0.1 fM to 10 nM, with a detection limit of 37 aM (S/N = 3).
这项研究提出了一种信号放大策略，该策略依赖于在两个典型的纳米结构层之间引入特定的聚合物薄膜，旨在改善平台的电性能，使其能够通过构建的生物传感设备表面的 HIV-1 基因的亚 femtomolar 检测来转导小的结合事件。所提出的复合材料是基于包含 p-氨基苯甲酸（PABA）的导电层排列的，该导电层夹在作为亚层的电化学还原氧化石墨烯（ERGO）和作为界面层的金纳米颗粒（AuNPs）之间。我们通过计算探索了这种设计如何使平台能够转导由 HIV-1 基因低浓度引起的生物传感器界面性质的微小变化，而无需任何放大策略。此外，我们发现夹在两个纳米结构层之间的 PABA 导电聚合物层起到了协同作用，这导致在相对较长的连续孵育和检测过程中具有良好的信号重复性和稳定性。使用这种导电层阵列的理由是实现了更低的检测极限。与用 ERGO/AuNPs 修饰的玻碳电极（GC）相比，用 ERGO/PABA/AuNPs 修饰的 GC 电极上探针 DNA 的固定观察到的性能激励我们进行计算，即使用从头算和半经验量子力学方法的混合方法，以发现其可能的分子尺度原因。还采用了快速单频阻抗测量（SFIM）来显著缩短测量时间并减少可能的非特异性阻抗变化。所提出的生物传感器用于评估从 0.1 fM 到 10 nM 的极宽浓度范围内的 DNA 靶标，检测限为 37 aM（S/N = 3）。
