Figure 2: The UV absorption spectra of HSA varying with the concentration 5-FU in the Tris-HCl buffer solution (pH 7.4) at room temperature (25°C). (a) Concentration of HSA (1 × 10-5 M) (1). Concentration of 5FU 0-45 μM with 5 μM interval (2-10). (b) Difference spectrum.