同轴静电纺丝制备核-壳型ATP超微电极

The increase in sensitivity and the micromation in size have become the research focus of the biosensors. Introduction of nanomaterials and nano-interface can effectively improve the biosensor's surface area, thereby increase its sensitivity. Graphene is a novel carbon nanomaterial, which has unique application prospects in the field of electrochemistry and electroanalytical chemistry. On the basis of the early developed modified electrode for the detection of adenosine triphosphate (ATP), the project intends to adopt coaxial electrospinning technique to prepare a core-shell structure ultramicroelectrode. Its inner electrode layer is mainly composed of graphite and molecular wires ( Diphenylacetylene ),the outer layer of the functionalized sensing layer is mainly composed of chitosan and graphene. Different kinds of functionized nanomaterials such as gold nanoparticles, silver nanoparticles,and so on, will be added to improve the properties. The ultramicroelectrode will be furthur used as a real-time monitor of ATP in biological tissue. As we all know, ATP is present in the living cells with the functions of intermediate of metabolism and energy exchange.In addition, ATP has also been confirmed to play an important role in the biological sense signal transmission. Useing superfine electrode for a real-time monitoring of ATP in biological tissue, which will be very important for a thorough understanding of biological organization coordination mechanism and the biological organization response to the implanted biomaterials and drugs injection.

灵敏度的提高和体积的微型化一直是生物传感器研究的热点。纳米材料和纳米界面的引入可以有效提高传感器的比表面积和灵敏度进而缩小传感器体积。石墨烯是一种新型的碳纳米材料，具有独特的电化学和电分析化学应用前景。本项目在前期研制的三磷酸腺苷（ATP）检测电极的基础上，拟采用同轴静电纺丝工艺制备核壳型ATP超微电极。电极内层主要由纳米石墨粉和分子导线（二苯乙炔）构成；电极外层为功能化传感层，主要由壳聚糖和石墨烯构成。在此基础上进一步研究纳米金、纳米银等粒子的添加对其性能的影响，并通过活体组织和细胞内的ATP测试来检测超微电极的实时测试效果。众所周知，ATP是活细胞进行能量交换的中介，近年来ATP还被证实在生物感知信号的传递中起到了重要作用。使用超微电极对生物组织中的ATP进行实时监测，对于深入了解生物组织的协调作用机制、植入生物材料和注射药物的组织应激反应与过程都有重要的意义。

项目通过静电纺丝法制备了多种纳米粒子/PAN复合纤维，再通过管式炉高温碳化制备了纳米粒子/碳纤维复合超微电极，并进一步将其用在CILE电极之上，成功构建了复合超微电极界面上的血红蛋白电化学传感器。.纳米粒子/碳纤维复合超微电极具有许多优良的性质，如大的比表面积，高的电传导率，优良的生物相容性以及制备成本低等。光谱实验结果表明Hb与超微电极复合后未发生变性。.电化学实验中，修饰电极在pH = 5.0的PBS缓冲液中的循环伏安曲线呈现出一对对称性良好的准可逆氧化还原峰，成功的实现了血红蛋白的直接电化学。.此外，以Nafion/Hb/CNF-Co3O4/CILE为工作电极的实验室自制三电极系统，应用于对三氯乙酸（TCA）和过氧化氢的电催化检测，实验结果均表明经超微电极修饰后的生物传感器具有良好的电催化性能。.修饰后生物传感器的电化学交流阻抗值由未修饰前的290.5Ω降低到16.4Ω（约为修饰前的20分之一）。对TCA催化反应的表观米氏常数KMapp为17.05 mmol/L，远低于一些文献值如Nafion/nano-CdS/Hb/CILE（0.216 mol/L），这说明说明了超微电极对TCA的电催化效果良好。.电极对H2O2催化反应的KMapp为27.20 mmol/L，这要比Nafion/Hb-CILE（0.108 mol/L）的电催化性好的多。.将修饰电极应用于对ATPNa2药物小分子的测试，其氧化峰电流值由未修饰前的55.39μA增加到93.94μA。复合电极在浓度为1x10-7- 4x10-3 mol/L范围内，随着ATPNa2浓度的不断增大，电化学信号也不断增大，氧化峰电流值与目标物浓度呈良好的线性关系。最低检测限为1.1x10-6 mol/L。.上述结果说明：在修饰了超微电极阵列后复合电极具有了优越的电催化性能。