Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
ChemSusChem. 2012 Oct;5(10):1918-25. doi: 10.1002/cssc.201200274. Epub 2012 Aug 20.
A novel nanocomposite based on ordered graphitized mesoporous carbon (GMC) and amino acid ionic liquids (AAIL) is obtained through controlled surface modification of GMC with hydrophilic AAILs (1-ethyl-3-methylimidazolium alanine, EMIM[Ala]), which is used as a platform for a tyrosinase biosensor to detect phenol. The GMC-AAIL nanocomposite possesses a better biocompatibility and improved aqueous-phase dispersion than hydrophobic GMC alone, owing to the introduction of hydrophilic and biocompatible AAILs. Comparative studies revealed that the catalytic activity of tyrosinase for phenol in phosphate buffer solution (PBS) containing EMIM[Ala] was about ten times higher than that in pure PBS. By entrapping tyrosinase molecules into the mesopores of GMC, making use of the synergy effect of GMC and AAIL (the "interspace confinement effect", the anti-fouling ability, and the biocompatible microenvironment), the GMC-AAIL-based biosensors display superior analytical performance to GMC-based ones in terms of signal-to-noise ratio, stability, repeatability, and working life. After 21-day storage, the electrode retained more than 90% of its initial response, indicating that surface modification of GMC with hydrophilic and biocompatible AAILs could significantly prolong the life of tyrosinase in vitro. The GMC10-EMIM[Ala]-based biosensor demonstrates a linear response for phenol concentrations from 0.1 to 10 µmol L(-1) with a low detection limit of 20 nmol L(-1) and sensitivity of 1385 mA cm(-2) M(-1). The GMC-AAIL nanocomposite proves to be a promising platform for enzyme-based biosensors and biocatalysis.
一种新型的纳米复合材料是通过将亲水的氨基酸离子液体（1-乙基-3-甲基咪唑丙氨酸，EMIM[Ala]）可控地修饰有序石墨化介孔碳（GMC）而得到的，它被用作酪氨酸酶生物传感器检测苯酚的平台。由于引入了亲水性和生物相容性的氨基酸离子液体，GMC-AAIL 纳米复合材料具有比单独的疏水性 GMC 更好的生物相容性和改进的水相分散性。对比研究表明，在含有 EMIM[Ala]的磷酸盐缓冲溶液（PBS）中，酪氨酸酶对苯酚的催化活性大约是纯 PBS 中的 10 倍。通过将酪氨酸酶分子包埋到 GMC 的介孔中，利用 GMC 和 AAIL 的协同效应（“间隔限制效应”、抗污染能力和生物相容性微环境），基于 GMC-AAIL 的生物传感器在信噪比、稳定性、重复性和工作寿命方面表现出优于基于 GMC 的生物传感器的分析性能。在 21 天的储存后，电极保留了超过 90%的初始响应，这表明用亲水和生物相容性的氨基酸离子液体对 GMC 进行表面修饰可以显著延长酪氨酸酶在体外的寿命。基于 GMC10-EMIM[Ala]的生物传感器对苯酚浓度从 0.1 到 10 µmol L(-1)的线性响应，检测下限为 20 nmol L(-1)，灵敏度为 1385 mA cm(-2) M(-1)。GMC-AAIL 纳米复合材料被证明是基于酶的生物传感器和生物催化的有前途的平台。
