蛋氨酸与化学增感剂的相互作用机理

THE INTERACTION MECHANISM OF METHIONINE AND CHEMICAL SENSITIZERS

运用X射线光电子能谱 (XPS)的ESCA扫描技术研究了蛋氨酸与不同化学增感剂相互作用及其中的硫、金、碳和氧等元素的化学形态和相对含量的变化规律 .发现蛋氨酸与不同的化学增感剂的反应机理是不尽相同的 .蛋氨酸与S增感剂不会发生任何化学反应 ,它们可以稳定地共存于同一体系之中 ;蛋氨酸可以将全部Au3+ 增感剂还原为Au ,其自身部分被氧化为蛋氨酸亚砜 ,并且在其脱质子的羟基部位与Au形成Au -O -C结构的金属配合物 .向蛋氨酸体系中加入S +Au增感剂后 ,体系中的氧化还原反应发生在外加的Au3+ 和S2 O32 - 之间 ,此时蛋氨酸的作用是将被S增感剂还原的Au络合 ,亦形成Au -O -C结构的配合物 .

The changes of the chemical states and the relative contents of sulfur, gold, carbon and oxygen after methionine reacted with different chemical sensitizers are studied by ESCA scanning technique of X?ray Photoelectron Spectroscopy(CPS). The results indicated that the interaction mechanism of methionine reacted with different chemical sensitizers is not identical. Any oxidation?reduction reaction did not occurred between methionine and sulfur sensitizer, they could coexist steadily in the same system. The methionine was oxidized to methionine sulfoxide, in the same time reducing Au 3+ to gold atom. The hydroxy of methionine could coordinate Au, forming Au-O-C coordinate metal complex. After S+Au sensitizers had been immersed into methionine system, oxidation?reduction reaction occurred between added thiosulfate and Au 3+ , methionine could coordinate Au which was reduced by sulfur sensitizer, also forming Au-O-C coordinate metal complex.