本文对有机染料罗丹明B(RhB)的荧光光谱受温度、应力以及pH值等物理或化学量的影响进行了研究。实验采用波长为405 nm的激光激发RhB/H610胶黏剂复合材料或RhB水溶液, 得到其荧光发射谱, 用谱峰频移及新型表征方法“谱带重心频移法”分析了环境参数对谱带位置的影响, 并通过线性拟合得到了RhB荧光谱带重心λB传感温度、压应力以及pH值的传感方程。结果表明, 谱带重心频移法有效抑制了光强涨落的白噪声, 能够显著提高传感的精度和稳定性。在测量范围中间值附近, 重心法对温度、压应力以及pH值传感的相对灵敏度分别为0.026%/℃, 0.09%/MPa和0.34%。由于RhB具有很高的发光效率和优异的生物相容性, 因此基于RhB荧光的传感方法在生物体系的检测表征方面具有较高的应用价值。

The influence of physical or chemical factors such as temperature, stress and pH value on the fluorescence spectrum of organic dye rhodamine B (RhB) was researched experimentally. An RhB/H610-resin composite and aqueous solutions of RhB were excited under a diode laser with a wavelength of 405 nm. Then, the fluorescence spectra were obtained. The peak shift and the newly proposed barycenter shift of the emission band were employed to characterize the effect of the environmental factors on the band location. The sensing functions of waveband barycenter λB with temperature, stress and pH value were respectively fitted linearly. The result shows that the barycenter method can effectively eliminate the random noise which mainly originated from the fluctuation of fluorescence intensity and light detector. Hence a finer precision was achieved in comparison with the peak shift method. The relative sensitivities of the barycentric method to the temperature, compressive stress and pH value are 0.026%/℃, 0.09%/MPa and 0.34% respectively. Taking the advantages of the high fluorescence efficiency and biological histocompatibility of RhB, the fluorescent sensing with RhB is a promising candidate for characterization of biological samples. Particularly, it is suitable for applications in the real-time monitoring of microwave treatment.