N‑(4-Aminobutyl)‑N‑ethylisopropanol and Co2+ Dual-Functionalized Core–Shell Fe3O4@Au/Ag Magnetic Nanomaterials with Strong and Stable Chemiluminescence for a Label-Free Exosome Immunosensor

• Published in: Analytical chemistry (Washington) 2023-08, Vol.95 (34), p.12982-12991
• Main Authors: Wang, Manli, Shu, Jiangnan, Wang, Shanshan, Lyu, Aihua, Wang, Yisha, Huang, Dabing, Cui, Hua
• Format: Article
• Language: English
• Subjects: Binding sites; Carbon dioxide; Chemiluminescence; Chemistry; Cobalt; Emission; Emissions; Exosomes; Gold; Immunosensors; Iron oxides; Labels; Lung cancer; Nanomaterials; Nanotechnology; Reagents; Silver
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.3c03135

Recently, magnetic beads (MBs) are moving toward chemiluminescence (CL) functional magnetic nanomaterials with a great potential for constructing label-free immunosensors. However, most of the CL-functionalized MBs suffer from scarce binding sites, easy aggregation, and leakage of CL reagents, which will ultimately affect the analytical performance of immunosensors. Herein, by using core–shell Fe3O4@Au/Ag magnetic nanomaterials as a nanoplatform, a novel N-(4-aminobutyl)-N-ethylisopropanol (ABEI) and Co2+ dual-functionalized magnetic nanomaterial, namely, Fe3O4@Au/Ag/ABEI/Co2+, with strong and stable CL emission was successfully synthesized. Its CL intensity was 36 and 3.5 times higher than that of MB@ABEI-Au/Co2+ and ABEI and Co2+ dual-functionalized chemiluminescent MBs previously reported by our group, respectively. It was found that the excellent CL performance of Fe3O4@Au/Ag/ABEI/Co2+ could be attributed to the enrichment effect of the Au/Ag shell and the synergistic enhance effect of the Au/Ag shell and Co2+. A related CL mechanism has been proposed. Afterward, based on the intense and stable CL emission of Fe3O4@Au/Ag/ABEI/Co2+, a sensitive and effective label-free CL immunosensor for exosome detection was established. It exhibited excellent analytical performance with a wide detection range of 3.1 × 103 to 3.1 × 108 particles/mL and a low detection limit of 2.1 × 103 particles/mL, which were better than the vast majority of the reported CL immunosensors. Moreover, the proposed label-free CL immunosensor was successfully used to detect exosomes in human serum samples and enabled us to distinguish healthy persons and lung cancer patients. It has the potential to be a powerful tool for exosome study and early cancer diagnosis.