Zhou Qian, Tang Dianping
Institute of Environmental and Analytical Science, School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, China.
J Mater Chem B. 2018 Nov 7;6(41):6585-6591. doi: 10.1039/c8tb01807c. Epub 2018 Sep 28.
A newly portable detection sensing platform based on a graphene oxide (GO)-gated mesoporous silica nanocontainer (MSN) was designed for arsenite detection through the target-responsive release of glucose from the MSN with a glucometer readout. To construct such a biosensing system, the arsenite aptamer was initially conjugated covalently onto the mesoporous silica nanoparticles through the epoxy-amino reaction. Thereafter, the indicators (glucose molecules) were gated into the pores by using graphene oxide nanosheets, on the basis of π-stacking interactions between the nucleobases and graphene. Upon target arsenite introduction, graphene oxide was displaced from the MSN thanks to a specific reaction between the analyte and the aptamer, thus resulting in the opening of the pores to release the loaded glucose molecules, which could be determined quantitatively by using a portable personal glucometer (PGM). Based on the different affinities between graphene and the analyte for the labeled aptamer on the MSN, the amount of released glucose molecules from the pores increased with the increasing arsentite concentrations. Under optimal conditions, the GO-gated aptasensing system exhibited good PGM responses relative to arsenite concentrations within the dynamic working range of 0.01-100 ng mL (ppb) at a detection limit of 2.3 pg mL (ppt). The coefficients of variation (CVs) for the reproducibility of intra-assay and inter-assay were below 9.1% and 11.6%, respectively. In addition, the methodology also displayed high specificity and selectivity towards target arsenite against other ions, and was applicable for monitoring arsenite in water samples, giving well-matched results in accordance with the referenced ICP-MS.
设计了一种基于氧化石墨烯（GO）门控介孔二氧化硅纳米容器（MSN）的新型便携式检测传感平台，用于通过用血糖仪读出从MSN中目标响应释放葡萄糖来检测亚砷酸盐。为构建这样的生物传感系统，首先通过环氧-氨基反应将亚砷酸盐适配体共价缀合到介孔二氧化硅纳米颗粒上。此后，基于核碱基与石墨烯之间的π-堆积相互作用，使用氧化石墨烯纳米片将指示剂（葡萄糖分子）门控到孔中。引入目标亚砷酸盐后，由于分析物与适配体之间的特异性反应，氧化石墨烯从MSN上被置换，从而导致孔打开以释放负载的葡萄糖分子，这些分子可以使用便携式个人血糖仪（PGM）进行定量测定。基于石墨烯与分析物对MSN上标记适配体的不同亲和力，从孔中释放的葡萄糖分子数量随着亚砷酸盐浓度的增加而增加。在最佳条件下，GO门控适配体传感系统在0.01 - 100 ng/mL（ppb）的动态工作范围内相对于亚砷酸盐浓度表现出良好的PGM响应，检测限为2.3 pg/mL（ppt）。批内和批间重现性的变异系数（CVs）分别低于9.1%和11.6%。此外，该方法对目标亚砷酸盐相对于其他离子还表现出高特异性和选择性，适用于监测水样中的亚砷酸盐，与参考电感耦合等离子体质谱法（ICP-MS）给出的结果匹配良好。
