title: Study on the interaction between oxolinic acid aggregates and protein and its analytical application.
abstract: It was found that oxolinic acid (OA) at high concentration can self-assemble into nano- to micro-meter scale OA aggregates in Tris-HCl (pH 7.48) buffer solution. The nanoparticles of OA were adopted as fluorescence probes in the quantitative analysis of proteins. Under optimum conditions, the fluorescence quenching extent of nanometer scale OA aggregates was in proportion to the concentration of albumins in the range of 3.0x10(-8) to 3.0x10(-5) g mL(-1) for bovine serum albumin (BSA) and 8.0x10(-8) to 8.0x10(-6) g mL(-1) for human serum albumin (HSA). The detection limits (S/N=3) were 3.4x10(-9) g mL(-1) for BSA, and 2.6x10(-8) g mL(-1) for HSA, respectively. Samples were satisfactorily determined. The interaction mechanism of the system was studied using fluorescence, UV-vis, resonance light scattering (RLS) and transmission electron microscope (TEM) technology, etc., indicating that the nonluminescent complex was formed between serum albumin molecular and OA, to disaggregate the self-association of OA, which resulted in the dominated static fluorescence quenching in the system.
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, Shandong, PR China. wux@sdu.edu.cn
authors.forename: Xia
authors.initials: X
authors.lastname: Wu
authors.forename: Jinhua
authors.initials: J
authors.lastname: Zheng
authors.forename: Honghong
authors.initials: H
authors.lastname: Ding
authors.forename: Dehuan
authors.initials: D
authors.lastname: Ran
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Song
authors.forename: Jinghe
authors.initials: J
authors.lastname: Yang
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D002021:Buffers; D002417:Cattle; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008027:Light; D008163:Luminescent Measurements; D008670:Metals / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry; D010093:Oxolinic Acid / Q000737:chemistry*; D012542:Scattering, Radiation; D012709:Serum Albumin / Q000032:analysis / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000032:analysis* / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D000596:Amino Acids; D002021:Buffers; D005456:Fluorescent Dyes; D008670:Metals; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; D010093:Oxolinic Acid