One-Step Protein Conjugation to Upconversion Nanoparticles

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• 作者：Jie Lu ; Yinghui Chen ; Deming Liu ; Wei Ren ; Yiqing Lu ; Yu Shi ; James Piper ; Ian Paulsen ; Dayong Jin
• 刊名：Analytical Chemistry
• 出版年：2015
• 出版时间：October 20, 2015
• 年：2015
• 卷：87
• 期：20
• 页码：10406-10413
• 全文大小：469K
• ISSN：1520-6882

文摘

The emerging upconversion nanoparticles offer a fascinating library of ultrasensitive luminescent probes for a range of biotechnology applications from biomarker discovery to single molecule tracking, early disease diagnosis, deep tissue imaging, and drug delivery and therapies. The effective bioconjugation of inorganic nanoparticles to the molecule-specific proteins, free of agglomeration, nonspecific binding, or biomolecule deactivation, is crucial for molecular recognition of target molecules or cells. The current available protocols require multiple steps which can lead to low probe stability, specificity, and reproducibility. Here we report a simple and rapid protein bioconjugation method based on a one-step ligand exchange using the DNAs as the linker. Our method benefits from the robust DNA鈥損rotein conjugates as well as from multiple ions binding capability. Protein can be preconjugated via an amino group at the 3鈥?end of a synthetic DNA molecule, so that the 5鈥?end phosphoric acid group and multiple phosphate oxygen atoms in the phosphodiester bonds are exposed to replace the oleic acid ligands on the surface of upconversion nanoparticles due to their stronger chelating capability to lanthanides. We demonstrated that our method can efficiently pull out the upconversion nanoparticles from organic solvent into an aqueous phase. The upconversion nanoparticles then become hydrophilic, stable, and specific biomolecules recognition. This allows us to successfully functionalize the upconversion nanoparticles with horseradish peroxidise (HRP) for catalytic colorimetric assay and for streptavidin (SA)鈥揵iotin immunoassays.