A sol-gel synthetic rote was proposed for preparation of optically transparent silica films with covalently bonded azobenzene dye, alizarin yellow. Effect of chemical immobilization on protolytic properties of pH sensor moieties was studied using UV–vis spectroscopy. It was found that indicator dye attached to the silica framework through amide linkage retains the ability to respond on pH change by color transition. The response time of surface azobenzene groups evaluated from the kinetic studies in acidic and neutral medium consists of 10 and 5 min, correspondingly. Acid ionization constants of individual and grafted alizarin yellow were evaluated by spectrophotometric titration in phosphate buffer solutions. It was found that involving of indicator dye carboxylic group in covalent bonding with silica surface leads to the shift of pK_a2 value, reflecting the dissociation of phenolic hydroxyl group, from 10.9 to 5.5. Influence of β-cyclodextrin on pH-sensing properties of individual and grafted alizarin yellow was evaluated by spectrophotometric titration in phosphate buffer solutions. Sensor material showed good reversibility, repeatability and long-term stability at immersion in aqueous solutions with pH in the range from 1 to 8.

提出了一种溶胶-凝胶合成死记号，用于制备具有共价键合的偶氮苯染料茜素黄的光学透明二氧化硅膜。使用紫外可见光谱研究了化学固定化对pH传感器部分蛋白水解特性的影响。发现通过酰胺键连接到二氧化硅骨架上的指示剂染料保留了通过颜色转变对pH变化做出响应的能力。通过在酸性和中性介质中的动力学研究评估的表面偶氮苯基的响应时间分别为10分钟和5分钟。在磷酸盐缓冲液中通过分光光度滴定法评估了单独的和接枝的茜素黄的酸电离常数。发现指示剂染料羧基与二氧化硅表面共价结合会导致pK的移动反映酚羟基解离的_a2值，从10.9至5.5。通过在磷酸盐缓冲液中分光光度滴定，评估了β-环糊精对单独的和接枝的茜素黄的pH敏感特性的影响。传感器材料浸入pH为1到8的水溶液中时显示出良好的可逆性，可重复性和长期稳定性。