Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Maria-Reiche-Strasse 2, 01109 Dresden, Germany.
Faculty of Mechanical Science and Engineering, Institute of Materials Science and Max Bergmann Center of Biomaterials, Technische Universität Dresden, 01062 Dresden, Germany.
Biosensors (Basel). 2024 Jul 13;14(7):341. doi: 10.3390/bios14070341.
The selection of an appropriate transducer is a key element in biosensor development. Currently, a wide variety of substrates and working electrode materials utilizing different fabrication techniques are used in the field of biosensors. In the frame of this study, the following three specific material configurations with gold-finish layers were investigated regarding their efficacy to be used as electrochemical (EC) biosensors: (I) a silicone-based sensor substrate with a layer configuration of 50 nm SiO/50 nm SiN/100 nm Au/30-50 nm WTi/140 nm SiO/bulk Si); (II) polyethylene naphthalate (PEN) with a gold inkjet-printed layer; and (III) polyethylene terephthalate (PET) with a screen-printed gold layer. Electrodes were characterized using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) to evaluate their performance as electrochemical transducers in an aptamer-based biosensor for the detection of cardiac troponin I using the redox molecule hexacyanoferrade/hexacyaniferrade (K3[Fe (CN)6]/K4[Fe (CN)6]. Baseline signals were obtained from clean electrodes after a specific cleaning procedure and after functionalization with the thiolate cardiac troponin I aptamers "Tro4" and "Tro6". With the goal of improving the PEN-based and PET-based performance, sintered PEN-based samples and PET-based samples with a carbon or silver layer under the gold were studied. The effect of a high number of immobilized aptamers will be tested in further work using the PEN-based sample. In this study, the charge-transfer resistance (Rct), anodic peak height (I), cathodic peak height (I) and peak separation (∆E) were determined. The PEN-based electrodes demonstrated better biosensor properties such as lower initial Rct values, a greater change in Rct after the immobilization of the Tro4 aptamer on its surface, higher I and I values and lower ∆E, which correlated with a higher number of immobilized aptamers compared with the other two types of samples functionalized using the same procedure.
选择合适的换能器是生物传感器开发的关键要素。目前，生物传感器领域使用了各种基底和工作电极材料，利用不同的制造技术。在本研究中，研究了以下三种具有金层的特定材料配置，以研究它们作为电化学（EC）生物传感器的有效性：（I）具有 50nmSiO/50nmSiN/100nmAu/30-50nmWTi/140nmSiO/体硅的硅基传感器基底的层配置；（II）金喷墨打印层的聚萘二甲酸乙二醇酯（PEN）；以及（III）具有丝网印刷金层的聚对苯二甲酸乙二醇酯（PET）。使用电化学阻抗谱（EIS）和循环伏安法（CV）对电极进行了表征，以评估它们作为基于适配体的生物传感器中电化学换能器的性能，用于检测心脏肌钙蛋白 I 使用氧化还原分子六氰合铁（III）/六氰合铁（II）（K3[Fe（CN）6]/K4[Fe（CN）6]。在经过特定的清洁程序后，从清洁电极获得基线信号，然后用硫醇心脏肌钙蛋白 I 适体“Tro4”和“Tro6”功能化。为了提高 PEN 基和 PET 基的性能，研究了烧结 PEN 基样品和在金下具有碳或银层的 PET 基样品。在进一步的工作中，将使用 PEN 基样品测试大量固定化适体的效果。在这项研究中，确定了电荷转移电阻（Rct）、阳极峰高（I）、阴极峰高（I）和峰分离（∆E）。与使用相同程序功能化的其他两种类型的样品相比，PEN 基电极表现出更好的生物传感器性能，例如更低的初始 Rct 值、在其表面固定 Tro4 适体后 Rct 的更大变化、更高的 I 和 I 值以及更低的 ∆E，这与固定化的适体数量更高相关。
