One-step in situ solid-substrate-based whole blood immunoassay based on FRET between upconversion and gold nanoparticles

• Published in: Biosensors & bioelectronics 2017-06, Vol.92, p.335-341
• Main Authors: Li, Cuixia, Zuo, Jing, Li, Qiqing, Chang, Yulei, Zhang, Youlin, Tu, Langping, Liu, Xiaomin, Xue, Bin, Zhao, Huiying, Zhang, Hong, Kong, Xianggui
• Format: Article
• Language: English
• Subjects: Animals; Erbium - chemistry; Fluorescence Resonance Energy Transfer - methods; Fluorescent Antibody Technique - methods; Fluorides - chemistry; FRET; Goats; Gold - chemistry; Humans; Immunoassay; Immunoglobulin G - analysis; Immunoglobulin G - blood; In situ; Limit of Detection; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Rabbits; Upconversion nanoparticles; Whole blood; Ytterbium - chemistry; Yttrium - chemistry
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2016.11.003

Despite their general clinical applications, current fluorescence-based immunoassays are confronted with serious challenges, e.g. the advance serum/ plasma separation and the tedious washing process in current heterogeneous approaches, and aggregation of particles, low sensitivity and the narrow linear range in homogeneous approaches. In this paper, these urgent problems were solved in a novel one-step in situ immunoassay of whole blood samples by combining the traditional fluorescence resonance energy transfer (FRET) technology (between upconversion nanoparticles (UCNPs) and gold nanoparticles (GNPs)) and the solid-substrate based immunoassay technology. The low detection limits of goat IgG (gIgG) as 0.042μg/mL in buffers, 0.51μg/mL in 20-fold diluted whole blood samples and a wide linear range from 0.75μg/mL to 60μg/mL in blood samples were achieved. To the best of our knowledge, it is the first one-step in situ solid-substrate-based immunoassay of whole blood samples with large linear detection range. This development provides a promising platform for a rapid and sensitive immunoassay of various bio-molecules directly in whole blood without tedious separation, washing steps and aggregation problems. •An immunoassay method was constructed by using UCNP-based FRET on a solid-substrate.•The approach successfully solved some shortcomings in the traditional immunoassays.•It is the first in situ solid-substrate-based immunoassay of whole blood samples.•A wide detection range of 0.75-60 μg/mL in whole blood samples was achieved.