School of the Environment and Safety Engineering , Jiangsu University , Zhenjiang , 212013 , P. R. China.
State Key Laboratory of Chemo/Biosensing and Chemometrics , Hunan University , Changsha 410082 , People's Republic of China.
Anal Chem. 2019 Feb 19;91(4):2908-2915. doi: 10.1021/acs.analchem.8b05047. Epub 2019 Jan 31.
For developing highly selective and sensitive electrochemical sensors for chiral recognition, taking advantage of the synthetical properties of β-cyclodextrin (β-CD, strong host-guest recognition) and carbon nanotubes wrapped with reduced graphene oxide (CNTs@rGO, excellent electrochemical property and large surface area), as well as the differences in binding affinity between β-CD and guest molecules, a dual signal electrochemical sensing strategy was proposed herein for the first time in chiral recognition based on the competitive host-guest interaction between probe and chiral isomers with β-CD/CNTs@rGO. As a model system, rhodamine B (RhB) and phenylalanine enantiomers (d- and l-Phe) were introduced as probe and target enantiomers, respectively. Due to the host-guest interactions, RhB can enter into the β-CD cavity, showing remarkable oxidation peak current of RhB. In the presence of l-Phe, competitive interaction with the β-CD cavity occurs and RhB are replaced by l-Phe owing to the stronger binding affinity between l-Phe and β-CD, which results in the peak current of RhB decreasing and the peak current of l-Phe appears, and interestingly, the changes of both signals linearly correlate with the concentration of l-Phe. As for d-Phe, it cannot replace RhB owing to the weaker binding affinity between d-Phe and β-CD. Based on this, a dual-signal electrochemical sensor was developed successfully for recognizing Phe. This dual-signal sensing strategy can provide highly selective and sensitive recognition compared to single-signal sensor and has important potential applications in chiral recognition.
为了开发用于手性识别的高选择性和高灵敏度的电化学传感器，利用β-环糊精（β-CD，强主体客体识别）和还原氧化石墨烯包裹的碳纳米管（CNTs@rGO，优异的电化学性能和大的表面积）的合成性质，以及β-CD 和客体分子之间结合亲和力的差异，本文首次提出了一种基于探针与β-CD/CNTs@rGO 之间的竞争主体客体相互作用的手性识别的双信号电化学传感策略。以罗丹明 B（RhB）和苯丙氨酸对映体（d-和 l-Phe）作为探针和目标对映体的模型体系。由于主体客体相互作用，RhB 可以进入β-CD 腔，显示出 RhB 的显著氧化峰电流。在存在 l-Phe 的情况下，由于 l-Phe 和β-CD 之间更强的结合亲和力，会发生与β-CD 腔的竞争相互作用，RhB 被 l-Phe 取代，这导致 RhB 的峰电流减小且出现 l-Phe 的峰电流，而且，两个信号的变化都与 l-Phe 的浓度呈线性相关。对于 d-Phe，由于 d-Phe 和β-CD 之间的结合亲和力较弱，它不能取代 RhB。基于此，成功开发了用于识别 Phe 的双信号电化学传感器。与单信号传感器相比，这种双信号传感策略可以提供更高的选择性和灵敏度，在手性识别中具有重要的潜在应用价值。
