Multifunctional phenylboronic acid-tagged fluorescent silica nanoparticles via thiol-ene click reaction for imaging sialic acid expressed on living cells.
Multifunctional fluorescent silica nanoparticles with phenylboronic acid tags were developed for labeling sialic acid on the surface of living cancer cells. In this paper, fluorescent silica nanoparticles (FSNPs) with strong and stable emission at 515 nm were firstly prepared through a reverse microemulsion process, and then modified with highly selective phenylboronic acid (PBA) tags on their surface via an aqueous 'thiol-ene' click reaction. These nanoparticles had a hydrodynamic diameter of 92.6 ± 9.1 nm, and a bright fluorescence signal, which is 366 times higher than that of a single dye molecule. Meanwhile, these PBA-tagged FSNPs were found very stable in aqueous solution as well as in cell culture medium, verified by transmission electron microscopy, X-ray photoelectron spectroscopy and zeta potential analysis. The over-expressed sialic acid (SA) on the membrane of living HeLa cells was visualized in situ by a confocal laser scanning microscopy, ascribed to the specific interaction between PBA and SA. Thus, the PBA-FSBPs showed a great potential in probing SA expressed on living cells with high selectivity and sensitivity.
Department of Chemistry, Fudan University, No. 220, Handan Road, Shanghai 200433, China.
Liwei
L
Cheng
Xianxia
X
Zhang
Zhengyong
Z
Zhang
Hui
H
Chen
Song
S
Zhang
Jilie
J
Kong
D001897:Boronic Acids / Q000737:chemistry*; D057930:Click Chemistry; D005456:Fluorescent Dyes; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D057054:Molecular Imaging / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D012680:Sensitivity and Specificity; D012794:Sialic Acids / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
D001897:Boronic Acids; D005456:Fluorescent Dyes; D012794:Sialic Acids; D013438:Sulfhydryl Compounds; D012822:Silicon Dioxide; C010686:benzeneboronic acid
Fluorescent silica nanoparticles; Living cell imaging; Phenylboronic acid tag; Sialic acid; Thiol-ene click reaction