Quantification of Human Serum Transferrin Based on High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry with Gold Nanoparticles Labeling

A simple and sensitive method for quantification of transferrin (Tf) in human serum by high performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometer (ICP-MS) with gold nanoparticles (AuNPs) labeling was established. Accurate quantification of standard Tf and Tf in human serum were achieved by measuring the concentration of AuNPs labeled on Tf. Tf could be incubated with most amount of AuNPs to form AuNPs. Tf in phosphate buffer (pH 6.8). Since gold atoms labeled to the Tf molecule could enhance the signals, accurate quantification of Tf in human serum could be achieved by gold signal measurement with ICP-MS after AuNPs. Tf was separated by HPLC. Good linear correlation coefficient (R-2 = 0.9959) was obtained between Au peak area on AuNPs-Tf and concentration of Tf with a wide linear response over 3 orders of magnitude, and the limit of detection was 6 ng/mL. The developed method was successfully applied for detection of Tf in human serum certified reference material (ERM-DA470/IFCC) after being verified by standard Tf. Good agreement was achieved and the quantitative recovery was in the range of 95.2% - 102.6%. Due to signal amplification of AuNPs and ultra-sensitive detection of ICP-MS, the sensitivity and accuracy were improved significantly compared to traditional enzyme-linked immunosorbent assay. Moreover, the measurement results could be directly traced to SI unit.