Department of Chemistry, Alfaisal University, Al Zahrawi Street, Al Maather, Al Takhassusi Road, Riyadh 11533, Saudi Arabia.
Department of Chemistry, Alfaisal University, Al Zahrawi Street, Al Maather, Al Takhassusi Road, Riyadh 11533, Saudi Arabia.
Mater Sci Eng C Mater Biol Appl. 2019 Aug;101:423-430. doi: 10.1016/j.msec.2019.04.001. Epub 2019 Apr 3.
The integration of carbon nanomaterials into electrochemical aptasensors has gained significant interest in the recent years because of their high electrical conductivity, mechanical strength, and large surface area. However, no comparative study has been reported so far between different carbon nanomaterials for aptasensing applications. Here, we report, a comparative investigation of six carbon electrode materials (carbon, graphene (G), graphene oxide (GO), multi-wall carbon nanotube (MWCNT), single walled carbon nanotube (SWCNT) and carbon nanofiber (CNF)) on the performance of glycated haemoglobin (HbA1c) aptasensor prepared by physical adsorption. The aptamers were non-covalently immobilized on the six nanomaterial electrodes via π-π stacking interactions between the DNA nucleobases and the surface of the carbon material which creates a barrier to the electron transfer. However, upon binding of the target protein to the aptamer, the aptamer dissociates from the surface leading to enhancement of the electron transfer which represent the basis of the detection. The aptamer adsorption, sensors responses and selectivity of the different nanomaterials were compared showing better performance of the SWCNT-based sensor. The voltammetric SWCNT aptasensors showed high sensitivity and selectivity with detection limits of 0.13 pg/mL and 0.03 pg/mL for total haemoglobin (tHb) and HbA1c, respectively. The aptasensor showed selectivity against other proteins in the blood including cystic fibrosis transmembrane conductance regulator (CFTR), survival motor neuron (SMN), dedicator of cytokinesis 8 (DOCK8), signal transducer and activator of transcription 3 (STAT3). This SWCNT aptasensor was superior to the reported detection assays for HbA1c in terms of sensitivity, selectivity and cost. Moreover, our results demonstrate that the choice of the carbon nanomaterial can have a profound impact on the biosensing performance.
近年来，由于碳纳米材料具有高导电性、机械强度和大比表面积，将其整合到电化学适体传感器中引起了人们的极大兴趣。然而，迄今为止，对于适体传感应用，不同碳纳米材料之间的比较研究尚未见报道。在这里，我们报告了对六种碳电极材料（碳、石墨烯（G）、氧化石墨烯（GO）、多壁碳纳米管（MWCNT）、单壁碳纳米管（SWCNT）和碳纳米纤维（CNF））的比较研究，这些材料用于通过物理吸附制备糖化血红蛋白（HbA1c）适体传感器。适体通过 DNA 碱基与碳材料表面之间的π-π堆积相互作用非共价固定在六种纳米材料电极上，这会形成电子转移的障碍。然而，当目标蛋白与适体结合时，适体从表面解离，导致电子转移增强，这是检测的基础。比较了不同纳米材料的适体吸附、传感器响应和选择性，结果表明基于 SWCNT 的传感器具有更好的性能。SWCNT 适体传感器具有高灵敏度和选择性，对总血红蛋白（tHb）和 HbA1c 的检测限分别为 0.13 pg/mL 和 0.03 pg/mL。该适体传感器对血液中的其他蛋白质具有选择性，包括囊性纤维化跨膜电导调节剂（CFTR）、生存运动神经元（SMN）、胞质分裂 8 专用蛋白（DOCK8）和信号转导和转录激活因子 3（STAT3）。与 HbA1c 的报道检测方法相比，该 SWCNT 适体传感器在灵敏度、选择性和成本方面具有优势。此外，我们的结果表明，碳纳米材料的选择会对生物传感性能产生深远影响。
