Determination of Bovine Serum Albumin by Fluorescence Spectrometry with o-Fluorophenylfluorone as a Fluorescent Probe

In PBS with pH 7.40, bovine serum albumin (BSA) could quench the fluorescence intensity of o-fluorophenylfluorone (o-FPF) and the fluorescence quenching intensity (ΔF) was enhanced by the addition of β-CD. Based on this, a method of fluorescence spectrometry with o-FPF as a fluorescent probe was proposed for the determination of BSA. Under the optimized conditions, a linear relationship was found between ΔF and the concentration of BSA in the range of 6.0×10-9-4.0×10-7mol·L-1, with the detection limit (3s/k) of 7.1×10-10mol·L-1. The method was applied to the determination of BSA in milk and milk powder samples, giving results in consistent with those obtained by coomassie blue staining method and RSDs (n=5) less than 4%. The mechanism of interaction between BSA with o-FPF was studied by measuring the fluorescence lifetime and investigating the temperature effect on the quenching constants and UV absorption spectrometry, and the results showed that the interaction mechanism between BSA and o-FPF was a static quenching process.