Detection of functional groups and antibodies on microfabricated surfaces by confocal microscopy

Abstract

Fluorescence confocal microscopy was used to characterize micron‐sized microfabricated silicon particles and planar oxide surfaces after silanization and immobilization of IgG antibody. Surfaces treated with amino‐ and mercaptosilanes were tested for the presence of amine and sulfhydryl groups by labeling with specific fluorescein probes. In addition, human antibody (IgG) was immobilized to the thiol‐coated microparticles using the heterobifunctional crosslinker succinimidyl 4‐(N‐maleimidolmethyl)‐cyclohexane‐1‐carboxylate. Estimates of the surface density of IgG were consistent with 8.3% of a monolayer of covalently‐bound antibody. Confocal images confirmed uniform layers of both silanes and antibodies on the microparticles. The sensitivity limit for the confocal measurements was determined to be as low as 1.5 × 10−5 fluors per nm2. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 60: 137–146, 1998.

Label-Free Toxin Detection by Means of Time-Resolved Electrochemical Impedance Spectroscopy

“…There are several advantages to use an APTES for the surface activation: it has both a non-hydrolysable hydroxyl group, which is highly reactive to the metal oxides and amine group that presents a reactive moiety, enabling strong interaction with corresponding Ab amino group [21]. Anti-SEB was covalently bonded on the silanized aluminum surface in the presence of glutaraldehyde, which resulted in the formation of well-recognizable surface structures of various Ab aggregates (see Figure 1b).…”

Bio-functionalization of Monodisperse Magnetic Nanoparticles and Their Use as Biomolecular Labels in a Magnetic Tunnel Junction Based Sensor

“…To prepare an avidin-patterned substrate, a PDMA stamp with the desired micro-fluidic network 18 was prepared and placed atop an amine-functionalized 11,19 SiO 2 substrate. Drops of FITClabeled avidin were then placed at one end of the microchannels, through which they flowed by capillary action (Figure 4a inset).…”

Exploitation of Diatom Frustules for Nanotechnology: Tethering Active Biomolecules

“…In addition, silanes are good chelating ligands because of their reactivity with hydroxyls, and they can couple organic groups to virtually any oxide surface. [5] In this study we have used APS to silanize the surface followed by reaction with the heterobifunctional crosslinker N-5-azido-2-nitrobenzoyloxysuccinimide (ANB-NOS). The crosslinker provides an amine-reactive N-hydroxysuccinimide (NHS) ester with a photoactivatable nitrophenyl azide, enabling antibodies to be tethered via their amine groups when exposed to UV light.…”