College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Biosens Bioelectron. 2013 Nov 15;49:243-8. doi: 10.1016/j.bios.2013.05.036. Epub 2013 May 29.
A simple and novel supramolecular hydrogel was prepared from ferrocene (Fc) modified amino acid phenylalanine (F) and utilized as electrochemical immunosensing platform for the detection of human IgG. Scanning electron microscopy (SEM) characterization indicated that the hydrogel is composed of fibrils with diameter around 50-100 nm and length extend to 1mm. When the prepared hydrogel was reacted with H2O2, the Fc moieties on the amino acid was oxidized, leading to the disruption of the hydrogel structure and the decrease of its redox signal, which was characterized in detail by SEM and the electrochemical method. Regarding the redox current decrease upon the reaction of the hydrogel with H2O2, the hydrogel modified electrode was utilized as immunosensing interface. After the construction of the immunosensor based on the traditional sandwich protocol with glucose oxidase (GOx) functionalized carbon nanotube (CNT) as detection antibody label, the GOx attached onto electrode surface would catalyze glucose reaction to produce H2O2 and cause the decrease of redox current of the electrode. The current change is proportional to the concentration of IgG detected in the range from 0.1 to 100 pg/mL. The high sensitivity, wide linear range and good reproducibility of the immunosensor indicate this immunosensing platform can be easily extended to the detection of other protein biomarkers.
一种简单新颖的超分子水凝胶由二茂铁（Fc）修饰的氨基酸苯丙氨酸（F）制备而成，并用作电化学免疫传感平台来检测人 IgG。扫描电子显微镜（SEM）表征表明，水凝胶由直径约 50-100nm 且长度延伸至 1mm 的纤维组成。当制备的水凝胶与 H2O2 反应时，氨基酸上的 Fc 部分被氧化，导致水凝胶结构的破坏和其氧化还原信号的降低，这通过 SEM 和电化学方法进行了详细表征。鉴于水凝胶与 H2O2 反应时氧化还原电流的降低，水凝胶修饰电极被用作免疫传感界面。基于传统的三明治方案，构建了基于葡萄糖氧化酶（GOx）功能化碳纳米管（CNT）作为检测抗体标记的免疫传感器后，附着在电极表面上的 GOx 会催化葡萄糖反应生成 H2O2，导致电极的氧化还原电流降低。电流变化与检测到的 IgG 浓度在 0.1 至 100pg/mL 的范围内成正比。免疫传感器的高灵敏度、宽线性范围和良好的重现性表明，该免疫传感平台可以很容易地扩展到其他蛋白质生物标志物的检测。
