1. AGET-ATRP Using Alcohols As Reducing Agents2.the Synthesis And Characterization Of The New ESIPT Sensors For Cysteine Detection

1. AGET-ATRP using alcohols as reducing agentsSince its discovery in1995, atom transfer radical polymerization (ATRP) has become an efficient technique for synthesis of well-defined polymers with desired molecular weight, narrow molecular weight distribution, and complex architecture. To perform the polymerization more conveniently, new ATRP techniques, such as reverse ATRP, activators (regenerated by electron transfer ATRP (A(R)GET-ATRP) have been developed using more stable metal species (Cu(II) or Fe(III)).The reducing agent plays a key role in an ATRP process. In an effort to make environmentally friendly, efficient, and cost-effective A(R)GET-ATRP procedures, rigorous studies have been devoted to find suitable reducing agents, which proceed in a manner devoid of side products, facilitate facile removal, and efficiently perform at catalytic concentrations. We have sought to explored more appreciated reducing agents for AGET-ATRP.In this part, alcohols have been investigated as reducing agents for activators generated by electron transfer ATRP (AGET-ATRP). The experimental results show that simple alcohols, such as methanol, ethanol, and ethylene glycol, can effectively reduce air-stable Cu(II) into active Cu(I) in situ in the polymerization system and promote the process of AGET-ATRP. Well-controlled AGET-ATRP of methyl acrylate, tert-butyl acrylate, and styrene has been successfully achieved in the presence of alcohols with catalytic amounts of Na2CO3in anisole. Polymerization of methyl acrylate in the presence of a limited amount of air was also successfully performed resulting in a poly(methyl acrylate) with Mn=6800and Mw/Mn=1.12. The use of alcohols as new reducing agents for AGET-ATRP, is a more promising strategy for the development of a viable process for industrial scale production, since alcohols are stable, environmentally friendly, and cost-effective.2. The synthesis and characterization of the new ESIPT sensors for cysteine detectionCysteine (Cys) is one of most important amino acids in human body. As a small-molecular-weight biological thiol, Cys possesses various important biochemical functions including biocatalysis, metal binding, post-translational modifications, and detoxification of xenobiotics. Cys deficiency also is implicated in many syndromes such as slow growth in children, skin lesions, hair depigmentation, liver damage and edema. As a result, developing a fast, high sensitive and high selectivity protocol for detecting Cys became more and more important. Compared to some traditional methods, fluorescence detection is advantageous in terms of high sensitivity and simplicity of operation. Thus, fluorescent probes capable of detection of Cys have received intense attention recently. Based on our previous works about control free radical living polymerization and flavones-based fluorescence platform, we designed two efficient Cys sensors and detailed investigated their sensing properties.(1). Synthesis and characterization of an ESIPT fluorescent dye MHF containing ESIPT flavones units as an efficient sensor for Cys detection. Both of the absorbance spectra and fluorescence spectra of MHF showed good response for Cys. The sensitivity of MHF was very high, and the detection limit was down to lμM, which could be used in biological detection. The fluorescence intensity of MHF was linearly proportional to the amount of Cys in the range of0μM-100μM, which showed its potential in quantitative detection of Cys. At last, we investigated the sensing properties of the MHF and the polymer based MHF units to demonstrate the mechanism we proposed.(2). Another ESIPT fluorescence polymer sensor PBHF was synthesized and fully characterized. Compared to the small molecular sensor BHF, the polymer sensor PBHF had faster response time and higher sensitivity. Both of the absorbance spectra and fluorescence spectra of PBHF showed good response for Cys, this indicated that the PBHF was a dual mode response sensor. The fluorescence intensity of PBHF was linearly proportional to the amount of Cys in the range of0μM-100μM, which showed its potential in quantitative detection of Cys. Besides, PBHF has a very good selectivity for Cys among other amino acid and common metal ions, only the hydrogen peroxide weakly influenced the sensing result.