本文利用荧光标记物的荧光猝灭效应测量水中溶解氧浓度。以塑料光纤作为传感和传光元件，为了提高溶解氧传感的灵敏度，传感头制成双锥形。以邻菲咯啉钌作为荧光标记物，用溶胶-凝胶法制备含有荧光标记物的敏感材料。根据Stern-Volmer 方程，通过测量荧光标记物的荧光强度来测定溶解氧的浓度。文中提出了一个模型来解释荧光强度与溶解氧浓度之间的亚线性关系。通过对所测得的曲线进行拟合，可以得出敏感膜约有85%的厚度不受氧漂白的作用。

A dissolved oxygen sensor is reported based on plastic optical fiber as sensor head and light transmit element. In order to enhance the systems sensitivity, the sensor head is bent into biconical-shape, and dissolved oxygen concentration is measured based on fluorescence quenching phenomenon. Dichlorotris (1, 10-phenanthroline) ruthenium (II) is used as fluorescence indicator and Sol-gel method is used to prepare the sensor material. According to Stern-Volmer equation, the dissolved oxygen concentration is linear with fluorescence intensity. We measure the relationship between dissolved oxygen concentration and fluorescence intensity and find that they are sub-linearity. In order to explain this phenomenon, we propose a model. By conic fitting the measured curve, the conclusion is drawn that 85% sensitivity film is not affected by dissolved oxygen.