Synchronous Fluorescence Determination of Protein with Functional Organic Nanoparticles

Abstract.

A new method for detecting protein using a synchronous fluorescence scan technique with a novel composite organic nanoparticle has been developed. The novel functional organic nanoparticle, dodecyl benzene sulfonic acid sodium salt (DBSS)-capped nano-anthracene, is easily prepared by re-precipitation under ultrasonic agitation. The surface of the fluorescent organic nanoparticle was covered with functional groups, which made these nanoparticles water-soluble, stable, and biocompatible. Compared to single organic fluorophores, these nanoparticles are brighter, more resistant to photobleaching, and do not suffer from blinking. We developed a sensitive synchronous fluorescence method for the rapid determination of proteins. With Δλ = 60 nm, maximum and constant synchronous fluorescence is produced at 339 nm. Under optimal conditions, the linear range is 0.04–13.0 µg mL⁻¹ for γ-globulin (γ-G), 0.1–11 µg mL⁻¹ for human serum albumin (HSA), and 0.1–11 µg mL⁻¹ for bovine serum albumin (BSA), respectively. The method is characterized by reproducibility, excellent accuracy and few interfering substances. The proposed method was applied to the determination of human serum samples collected from a hospital, and the results were in good agreement with those reported by the hospital, indicating that the method presented here is not only sensitive and simple, but also reliable and suitable for practical application.