By using fluorescence spectroscopy,the interaction between nitrobenzene( NB) and bovine serum albumin( BSA) has been discussed in this paper with different experimental conditions,including acidity,temperature and reaction time. The results showed that the best quenching effect of NB on BSA occurred in 0. 05 mol·L-1Tris-HCl buffer solutions(pH 7. 50)when the optimum exci-tation and emission wavelength were 280 nm and 342 nm,respectively. The binding constants(KB)for NB and BSA at 289,304 and 318K are 1. 25 × 104 ,1. 00 × 104 and 0. 833 × 104 L·mol-1 , respectively. The thermodynamic parameters,ΔH calculated by using Gibbs-Helmholtz Equation is-10. 7 kJ·mol-1 and ΔS is 41. 4 J·mol-1·K-1 . The interactions between NB and BSA is ascribed to the electrostatic force. The experimental results demonstrated that the fluorescence quenching mechanism is static quenching,which has been further confirmed by ultraviolet absorption spectrometry.%本文应用荧光分析法研究了不同酸度、温度和反应时间条件下,硝基苯对牛血清蛋白( BSA)的荧光猝灭作用。实验结果表明在激发波长λex=280nm,发射波长λem=342nm,浓度为0．05 mol·L-1,pH=7．50的Tris-HCl缓冲溶液中,猝灭效果最为明显。计算289,304和318 K 温度下二者的结合常数分别为：1．25×104、1．00×104和0．833×104 L·mol-1。通过Gibbs-Helmholtz 方程对其相互作用的热力学参数进行计算(ΔH=-10．7 kJ· moL-1；ΔS=41．4 J·moL-1·K-1),表明二者之间是静电相互作用。实验结果表明,硝基苯对牛血清蛋白荧光猝灭方式为静态猝灭,最后使用紫外吸收光谱法对其作用机理进一步确认。
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