Program in Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
Metallurgy and Materials Science Research Institute, Chulalongkorn University, Soi Chula 12, Phayathai Road, Wangmai, Patumwan, Bangkok, 10330, Thailand.
Talanta. 2024 Apr 1;270:125510. doi: 10.1016/j.talanta.2023.125510. Epub 2023 Dec 5.
Enzymatic electrochemical biosensor is the most common analytical platform for medical diagnosis. To mimic the biological environment of the enzyme for maintaining the function of biosensor, zwitterionic hydrogels have been recognized as effective matrices for enzymatic immobilization. Herein, a zwitterionic hydrogel derived from a copolymer, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-N-methacryloyloxyethyl tyrosine methylester (MAT)] (PMM) was firstly applied as versatile coating to preserve stability and activity of oxidase enzymes, glucose oxidase (GOx) and lactate oxidase (LOx) for enzymatic electrochemical sensor. A screen-printed carbon electrode (SPCE) was sequentially coated with nitrogen-doped graphene (NDG), oxidase enzyme, and PMM mixed with Ru(II)bpy and (NH)SO followed by visible light irradiation for 3 min to induce PMM gelation. Electrochemical detection of glucose and lactate using the modified SPCE was performed via amperometry in the presence of hydrogen peroxide. The activity of both GOx and LOx immobilized on the modified SPCE was well maintained for 49 days at 87 and 80 %, respectively. Additionally, two different electrodes, a screen-printed graphene electrode (SPGE), and a screen-printed silver electrode (SPAgE), similarly modified gave the same satisfactory detection of spiked glucose and lactate in human plasma and sweat with 93-118 % recovery. This indicates the potential of the PMM hydrogel as a universal platform for preservation of enzymes which can be easily fabricated without the need for specific chemical modification of the electrode.
酶电化学生物传感器是医学诊断中最常用的分析平台。为了模拟酶的生物环境以维持生物传感器的功能，两性离子水凝胶已被认为是酶固定的有效基质。本文首次将一种由共聚体聚[2-(甲基丙烯酰氧基)乙基磷酸胆碱(MPC)-co-N-(甲基丙烯酰氧基)乙基酪氨酸甲酯(MAT)]（PMM）衍生的两性离子水凝胶用作多功能涂层，以保持氧化酶（葡萄糖氧化酶（GOx）和乳酸氧化酶（LOx）的稳定性和活性，用于酶电化学传感器。依次将氮掺杂石墨烯（NDG）、氧化酶和 PMM 与 Ru(II)bpy 和（NH）SO 混合，然后用可见光照射 3 分钟以诱导 PMM 凝胶化，将修饰后的碳糊电极（SPCE）进行层层组装。在存在过氧化氢的情况下，通过安培法对修饰后的 SPCE 进行电化学检测，以检测葡萄糖和乳酸。固定在修饰的 SPCE 上的 GOx 和 LOx 的活性分别在 87%和 80%的条件下保持 49 天。此外，用同样方法修饰的两种不同电极，即印刷石墨烯电极（SPGE）和印刷银电极（SPAgE），对人血浆和汗液中添加的葡萄糖和乳酸进行了同样令人满意的检测，回收率为 93-118%。这表明 PMM 水凝胶作为一种通用的酶保存平台具有潜力，它可以很容易地制造，而不需要对电极进行特定的化学修饰。
