Characteristic And Applications For Functionalization Of Solid Interface Via Micheal Addition Reaction

Chapter one:PerfaceBasic concept, characteristic, methods for characterization and applications of SAMs are introduced. The important features, synthetic methods and applications of gold nanoparticles are presented as well as the features of catechol.Chapter two:A Colorimetric Sensor Based on Catechol-terminated Mixed Self-Assembled Monolayers Modified Gold Nanoparticles for Ultrasensitive Detections of Copper ionsA colorimetric sensor for Cu (Ⅱ) ions has been developedbasd on mixed self-assembled monolayers (SAMs) modified gold nanoparticles (AuNPs).The AuNPs were modified with mixed SAMs consisting of mercaptosuccinic acid and the product of electrochemically triggered Michael addition reaction of4-thiouracil and catechol. In the presence of Cu (Ⅱ) ions, the coordinationof Cu2+to catechol-terminated AuNPs leads to the aggregation-induced changes of surface plasmon resonance. The cost-effective chemical sensor allows rapid,sensitive and selective detection of Cu2+ions, indicating its potential application in environmental field.Chapter three:An Electrochemical Platform for Kinetic studies for Acetylcholinesterase Activity and Inhibition Effect of Inhibitors Based on Michael Addition Reaction between Thiocholine and Catechol-Terminated SAMsAn electrochemical platform for acetylcholinesterase (AChE) activity assay and its inhibitors screening is developed based on the Michael addition reaction of thiocholine, the hydrolysis product of acetylthiocholine (AsCh) in the presence of AChE, with the electrogenerated o-quinone of catechol-terminated SAMs on a gold electrode. For understanding and confirming the mechanism of the reaction, the electrochemical behaviors of Michael addition reaction of one model compound—glutathione (GSH), towards the catechol-terminated SAMs has been studied. The enzyme kinetics and the inhibition effects of three types of AChE inhibitors, which are tacrine, carbofuran and parathion-methyl, have been investigated using amperometric method. Among these three inhibitors, tacrine exhibits the strongest inhibiting effect, which is reinforced by the resulting data of kinetic studies on each inhibitor’s influence upon the enzyme activity.Chapter four:Electrochemically Triggered Michael Addition on the Self-Assembly of4-Thiouracil:Immobilizing Ni(II) and Cu (Ⅱ) for Detections of HistidineIn this paper, catechol was utilized as the electrophile for Michael addition reaction with the self-assembled monolayer (SAM) of4-thiouracil (4-TU) via electrochemical triggering. The SAMs can immobilize Ni2+through forming coordiation complexwith it while histidine can complex with the metal ion as well and the formed complex is more stable. Based on the above studies, the catechol-terminated SAMs provide a potential platform for amino acid recognition and detection.