Department of Engineering and Technology, Liverpool John Moore's University, Liverpool L3 3AF, UK.
Microbiology at Interfaces Group, Manchester Metropolitan University, Manchester M1 5GD, UK.
Sensors (Basel). 2022 Jan 16;22(2):675. doi: 10.3390/s22020675.
Carbon nanomaterials have gained significant interest over recent years in the field of electrochemistry, and they may be limited in their use due to issues with their difficulty in dispersion. Enzymes are prime components for detecting biological molecules and enabling electrochemical interactions, but they may also enhance multiwalled carbon nanotube (MWCNT) dispersion. This study evaluated a MWCNT and diamine oxidase enzyme (DAO)-functionalised screen-printed electrode (SPE) to demonstrate improved methods of MWCNT functionalisation and dispersion. MWCNT morphology and dispersion was determined using UV-Vis spectroscopy (UV-Vis) and scanning electron microscopy (SEM). Carboxyl groups were introduced onto the MWCNT surfaces using acid etching. MWCNT functionalisation was carried out using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and -Hydroxysuccinimide (NHS), followed by DAO conjugation and glutaraldehyde (GA) crosslinking. Modified C-MWNCT/EDC-NHS/DAO/GA was drop cast onto SPEs. Modified and unmodified electrodes after MWCNT functionalisation were characterised using optical profilometry (roughness), water contact angle measurements (wettability), Raman spectroscopy and energy dispersive X-ray spectroscopy (EDX) (vibrational modes and elemental composition, respectively). The results demonstrated that the addition of the DAO improved MWCNT homogenous dispersion and the solution demonstrated enhanced stability which remained over two days. Drop casting of C-MWCNT/EDC-NHS/DAO/GA onto carbon screen-printed electrodes increased the surface roughness and wettability. UV-Vis, SEM, Raman and EDX analysis determined the presence of carboxylated MWCNT variants from their non-carboxylated counterparts. Electrochemical analysis demonstrated an efficient electron transfer rate process and a diffusion-controlled redox process. The modification of such electrodes may be utilised for the development of biosensors which could be utilised to support a range of healthcare related fields.
碳纳米材料在电化学领域近年来引起了广泛关注，但由于其分散性困难，其应用可能受到限制。酶是检测生物分子和实现电化学相互作用的主要成分，但它们也可以增强多壁碳纳米管 (MWCNT) 的分散性。本研究评估了 MWCNT 和二胺氧化酶 (DAO) 功能化的丝网印刷电极 (SPE)，以展示 MWCNT 功能化和分散的改进方法。MWCNT 形态和分散度通过紫外-可见光谱 (UV-Vis) 和扫描电子显微镜 (SEM) 来确定。MWCNT 表面使用酸刻蚀引入羧基基团。MWCNT 功能化使用 1-乙基-3-(3-二甲基氨基丙基)碳二亚胺盐酸盐 (EDC) 和 -羟基琥珀酰亚胺 (NHS) 进行，然后进行 DAO 缀合和戊二醛 (GA) 交联。修饰后的 C-MWNCT/EDC-NHS/DAO/GA 被滴铸到 SPE 上。MWCNT 功能化后的修饰和未修饰电极使用光学轮廓仪 (粗糙度)、水接触角测量 (润湿性)、拉曼光谱和能量色散 X 射线光谱 (EDX) (分别为振动模式和元素组成) 进行表征。结果表明，DAO 的添加改善了 MWCNT 的均匀分散，并且该溶液表现出增强的稳定性，在两天内保持不变。C-MWCNT/EDC-NHS/DAO/GA 滴铸到碳丝网印刷电极上增加了表面粗糙度和润湿性。UV-Vis、SEM、Raman 和 EDX 分析确定了存在羧基化 MWCNT 变体与其非羧基化对应物的存在。电化学分析表明，存在有效的电子转移速率过程和扩散控制的氧化还原过程。这种电极的修饰可用于开发生物传感器，可用于支持一系列与医疗保健相关的领域。
