Studies On Novel Chiralsensors Based On Carbon Nanomaterials For The Recognition Of Amino Acids And Its Derivatives

Chirality is the common phenomenon in nature, and chiral compound is the basic component of living body. Different architectonic chiral compounds can exhibit distinct function in the field of medicine, clinic, environment and new materials. A pair of chiral drugs may exhibit very different medical effects toward patients. One enantiomer may be effective for a kind of disease, while the other one may be ineffectiveine, even toxic. chiral recognition is becoming one of the frontiers of chemistry and electrochemistry. Hence, based on the current situation and significance of chiral investigation, the novel chiral nanomaterials modified electrodes to design and fabricate chiral surface became an overarching concern for all researchers.Our work focuses on the preparation of carbon nanomaterials, the construction of the chiral interface and the development of sensitivity enhancement electrochemical chiral sensors for amino acid and its derivatives. Such work may not only offer valuable reference to the research of chiral drugs, but also help to comprehend the high selectivity of chiral molecular species in biosystems. The main research works are included as follows:1. A chiral interface has been designed for specific recognition of carboxylic acids using multilayer architectures of β-cyclodextrin (β-CD) and methylene blue/reduce-graphene (MB/rGO) on glassy carbon electrodes. The advantages of β-CD as a chiral selector and MB/rGO composite as an electrochemical indicator were perfectly presented in this novel interface. It displayed good redox signal for sensing chiral target with high sensitivity and conductivity. Enormous signal differences were obtained after adsorption of target L isomer, due to strong blocking of the electron transfer process of methylene blue. Meanwhile mandelic acid was found to be the best chiral guest and obtained more effective chiral recognition.2. Through the amide group of glutamic acid enantiomer and oxygen-containing groups (e.g., epoxy and carboxyl groups) in graphene oxide, chiral functionalized graphene nanosheets were synthesized, which showed good enantioselective recognition of3,4-dihydroxyphenylalanine. The chiral graphene hybrids should be used as novel promising materials for biological and pharmacological applications.3. A new strategy is established for detecting chiral amino acids based on a redox signal of HbFe(Ⅱ)/HbFe(Ⅲ) modulated in the presence of a copper complex is designed. The Cu(Ⅱ) complex attacks Hb immediately in a site-specific manner. The sensor shows a highly selective recognition of arginine enantiomers. Highly chiral-specific sensing of D-arginine in amino acids was observed. As a reagentless, sensitive sensor, the reaction between Hb and copper complexes with amino acids giving rise to a stereoselective behavior, which has not been achieved in the earlier studies, is presented in this work. The new strategy is a potential step to see how the metal ion affects the interaction between different enantionmers and biological molecules.