Nano-graphene oxide carboxylation for efficient bioconjugation applications: a quantitative optimization approach
Nano-graphene oxide carboxylation for efficient bioconjugation applications: a quantitative optimization approach
复制标题
DOI：
10.1007/s11051-015-2888-6
复制
发表时间：
2015-02-13
影响因子：
2.5
通讯作者：
Faghihi, Shahab
中科院分区：
文献类型：
--
作者：
Imani, Rana;Emami, Shahriar Hojjati;Faghihi, Shahab
提出了一种用氯乙酸羧化氧化石墨烯（GO）的方法，其精确地优化和控制用于生物缀合应用的过程的功效。纳米氧化石墨烯片（NGOS）上的COOH基团的定量通过新的比色亚甲蓝（MB）测定进行。在强碱性条件下，用氯乙酸处理GO并使其羧基化。用扫描电子显微镜、透射电子显微镜和原子力显微镜对所制备的非晶半导体的尺寸和形貌进行了表征。采用傅里叶变换红外光谱（FTIR）、紫外-可见光谱（UV-Vis）、X射线衍射（XRD）、原子力显微镜（AFM）和zeta电位等分析手段，研究了酸碱摩尔比对非晶半导体的物理、化学和形貌的影响。为了评估生物缀合功效，合成的具有不同羧化比率的纳米载体被作为含有胺基的生物分子模型的八精氨酸肽序列（R8）官能化。附接至石墨烯纳米片表面的R8肽的定量用基于比色的测定法进行，所述测定法包括施加2，4，6_三硝基苯磺酸（TNBS）。结果表明，羧化后纳米片的厚度和横向尺寸分别减小到0.8 nm和50-100 nm。X-射线衍射分析表明，纳米片层间距受氯乙酸与碱的比例的影响。MB分析表明，在NGOS表面上的COOH基团在酸碱比为2时最大化，这通过FTIR、XRD和zeta电位证实。TNBS测定还显示，与裸NGOS相比，优化的羧化NGOS样品与八精氨酸肽的生物缀合效率高2.5倍。本工作提供了证据，证明在优化条件下用氯乙酸处理GO将产生官能化的高表面积纳米基底，其可用于随后的有效生物缀合应用。[图形]。
A method for carboxylation of graphene oxide (GO) with chloroacetic acid that precisely optimizes and controls the efficacy of the process for bioconjugation applications is proposed. Quantification of COOH groups on nano-graphene oxide sheets (NGOS) is performed by novel colorimetric methylene blue (MB) assay. The GO is synthesized and carboxylated by chloroacetic acid treatment under strong basic condition. The size and morphology of the as-prepared NGOS are characterized by scanning electron microscopy, transmission electron microscopy (TEM), and atomic force microscopy (AFM). The effect of acid to base molar ratio on the physical, chemical, and morphological properties of NGOS is analyzed by Fourier-transformed infrared spectrometry (FTIR), UV-Vis spectroscopy, X-ray diffraction (XRD), AFM, and zeta potential. For evaluation of bioconjugation efficacy, the synthesized nano-carriers with different carboxylation ratios are functionalized by octaarginine peptide sequence (R8) as a biomolecule model containing amine groups. The quantification of attached R8 peptides to graphene nano-sheets' surface is performed with a colorimetric-based assay which includes the application of 2,4,6-Trinitrobenzene sulfonic acid (TNBS). The results show that the thickness and lateral size of nanosheets are dramatically decreased to 0.8 nm and 50-100 nm after carboxylation process, respectively. X-ray analysis shows the nano-sheets interlaying space is affected by the alteration of chloroacetic acid to base ratio. The MB assay reveals that the COOH groups on the surface of NGOS are maximized at the acid to base ratio of 2 which is confirmed by FTIR, XRD, and zeta potential. The TNBS assay also shows that bioconjugation of the optimized carboxylated NGOS sample with octaarginine peptide is 2.5 times more efficient compared to bare NGOS. The present work provides evidence that treatment of GO by chloroacetic acid under an optimized condition would create a functionalized high surface area nano-substrate which can be used for subsequent efficient bioconjugation applications.[GRAPHICS].