title: Fast and sensitive detection of protein concentration in mild environments.
abstract: Determination of protein concentration in mild environments is of great significance in the clinic diagnose and bioassay. Herein, a simple, fast and sensitive method for protein quantitative determination in neutral solution (pH 7.0) is developed. This assay is based on competition adsorption of the sample protein and fluorescently labeled dog serum albumin (FITC-DSA) onto gold nanoparticles (AuNPs). As the competitor FITC-DSA molecules are added into the mixture solution of sample protein conjugated AuNPs, they will compete for active sites of AuNPs, resulting in decrease in fluorescence intensity due to the quenching effect of AuNPs via fluorescence resonance energy transfer (FRET). Thus, quantitative determination of sample protein concentration can be achieved. Under the optimum conditions, the decrease in fluorescence intensity of the solution is related to the concentration of sample protein and a low detection limit of 0.01 µg/mL BSA can be achieved in 5 min. For the validation of our strategy in practical applications, the total protein content in human serum was determined using the as-proposed method. The result is in well agreement with that of measured by other conventional methods, suggesting a simple, accurate, and mild approach for protein detection in bioassay.
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China; Department of Physical Chemistry, School of Science, China Pharmaceutical University, Nanjing 211198, China.
authors: Chen
authors: C
authors: Wang
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors: Yue
authors: Y
authors: Zhou
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
authors: Ke-Xin
authors: KX
authors: Zhang
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China; Department of Physical Chemistry, School of Science, China Pharmaceutical University, Nanjing 211198, China.
authors: Xing-Guo
authors: XG
authors: Nie
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China. Electronic address: xhxia@nju.edu.cn.
authors: Xing-Hua
authors: XH
authors: Xia
mesh_terms: D000327:Adsorption; D005453:Fluorescence; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D011506:Proteins / Q000032:analysis*; D044967:Serum / Q000737:chemistry; D012709:Serum Albumin / Q000737:chemistry
chemical_list: D011506:Proteins; D012709:Serum Albumin; D006046:Gold
keywords: AuNPs; BSA; Competition adsorption; Human serum; Protein concentration