Achieving a biosensing interface with desirable performance is essential to a successful biosensor. In this paper, we developed a robust aptasensor by modifying methylene blue loaded graphene oxide (GO/MB) and ferrocene-labeled aptamer onto glassy carbon (GC) electrodes to realize the dual electrochemical signal mode ratiometric quantification of vascular endothelial growth factor (VEGF) in serum. For comparison, two sensing interfaces based on the covalent attachment (GC-ph-GO/MB-streptavidin-aptamer) and physical absorption GC-GO/MB-streptavidin-aptamer) of GO/MB to GC electrodes were fabricated, respectively. Redox molecule ferrocene labeled structure-switching aptamers having affinity to VEGF were used as the recognition probes providing electrochemical signal readout with the presence of the analyte VEGF. Larger amount of aptamers was observed on the GC-GO/MB-streptavidin-aptamer than that on GC-ph-GO/MB-streptavidin-aptamer while having the similar stability, which contributed to the higher sensitivity of GC-GO/MB-streptavidin-aptamer. The linear range of GC-GO/MB-streptavidin-aptamer and GC-ph-GO/MB-streptavidin-aptamer for detection of VEGF was 10–500 pg mL⁻¹ and 20–500 pg mL⁻¹, respectively. The GC-GO/MB-streptavidin-aptamer surface was able to realize the dual-signal mode ratiometric quantification of VEGF with wider linear range comparing with a single-signal mode detection. This electrochemical apatasensor provides a robust universal biosensing platform for sensitive ratiometric detection of a spectrum of analytes in real time.

实现具有理想性能的生物传感界面对于成功的生物传感器至关重要。在本文中，我们通过将亚甲基蓝负载的氧化石墨烯（GO / MB）和二茂铁标记的适体修饰到玻璃碳（GC）电极上，开发了一种鲁棒的适体传感器，以实现血管内皮生长因子（VEGF）的双电化学信号模式比例定量在血清中。为了进行比较，分别制造了基于GO / MB与GC电极共价连接的两个传感界面（GC-ph-GO / MB-链霉亲和素-适体）和物理吸收GC-GO / MB-链霉亲和素-适体。对VEGF具有亲和力的氧化还原分子二茂铁标记的结构转换适体用作识别探针，可在存在分析物VEGF的情况下提供电化学信号读出。与具有类似稳定性的GC-GO / MB-链霉亲和素-适体相比，在GC-GO / MB-链霉亲和素-适体上观察到更多的适体，这有助于GC-GO / MB-更高的灵敏度。链霉亲和素适体。用于检测VEGF的GC-GO / MB-链霉抗生物素蛋白适体和GC-ph-GO / MB-链霉抗生物素蛋白适体的线性范围是10–500 pg mL^-1和20–500 pg mL ^-1。与单信号模式检测相比，GC-GO / MB-链霉亲和素-适体表面能够实现更宽的线性范围的VEGF双信号模式比例定量。这款电化学适体传感器提供了强大的通用生物传感平台，可以实时灵敏地按比例检测各种分析物。