Synthesis and application of streptavidin functionalized organosilica microparticles

Abstract

This article reports on the chemical synthesis, functionalization and application of streptavidin (SA)-coated organosilica microparticles. Thiol-functionalized organosilica microparticles are synthesized via a two-step approach involving acid-catalyzed hydrolysis and condensation of 3-mercaptopropyl trimethoxysilane (MPS), followed by base-catalyzed condensation. The surfaces of these particles are modified with 3-aminopropyltriethoxysilane (APS), and characterized by FTIR, XPS, and TGA. Then, APSfunctionalized microparticles are covalently coated with SAs by using glutaraldehyde as a coupling agent, and characterized by FTIR, SEM, and AFM. Immobilization of biotinylated k DNA onto microparticles via SA-biotin immuoreaction is confirmed by confocal microscopy. The results show that these SA-functionalized organosilica microparticles are useful carriers for DNA manipulation at the single molecule level.

High efficiency capture of biomarker miRNA15a for noninvasive diagnosis of malignant kidney tumors

“…30 The surface-conjugation step involving conversion of carboxyl function of Fe 3 O 4 @DHCA NCs via carbodiimide coupling reaction was verified by the specific absorption band due to SAV that was found to appear at 1637 cm −1 corresponding to the amide groups located at the eight antiparallel β-strands of SAV. 31,32 Additionally, we evaluated the magnetic separation of IONCs in water to achieve complete purification within 3 min (Fig. 3G).…”

Replicating programmed colloidal sequences

“…1) Fabrication of the primer sequences: The starting point for the replication experiments are colloids coated with complementary DNA strands that can self-assemble. We use existing procedures to functionalize 2.7 µm SiO 2 colloids with streptavidin [26] or use commercial streptavidin-coated magnetic colloids and then add biotinylated double-stranded DNA (dsDNA) with a 6base pair sticky end on those colloids [6]. The DNA coating is determined to be around 1.3-0.5 10 6 strands per particle with a melting temperature of 36.5±1.2…”

“…1 Methods Summary DNA was grafted onto the colloids with streptavidin using protocols adapted from literature [6,26]. Following functionalization, the DNA-coated colloids were stored in a phosphate buffer (10 mM phosphate, 50 mM NaCl, 0.5 % Pluronic F-127, pH 7.4) at 0.5 % w/w.…”