A novel biosensing interfacial design produced by assembling nano-Au particles on amine-terminated plasma-polymerized films

Abstract

A novel biosensing interfacial design strategy has, for the first time, been produced by assembling nano-Au particles on amine-terminated plasma-polymerized films (PPF). A quartz-crystal microbalance (QCM) as a model transducer was deposited with PPF of n-butylamine by use of a glow discharge and then treated with nano-Au particles. The kinetic assembly process and conditions were studied using the real-time-output device and the surface topology of the resulting crystal was characterized by atomic force microscopy (AFM) imaging. Based on analysis of the experimental data, including the association constant of Au-amine interaction, the assembly mechanism is considered to be partly or even mainly chemical adsorption. Moreover, immobilization of anti-human IgM antibody (IgM Ab), as an example, on the developed PPF-Au interface was investigated. It was found that antibody molecules immobilized by the proposed procedure had higher immunological activity than those immobilized by the conventional glutaraldehyde (GLU) cross-linking procedure or the direct gold-attachment procedure. The newly developed sensor had a better response, with a detection limit of IgM concentration as low as approximately 1.00 microg mL(-1). In particular, the extremely high stability of both PPF and nano-Au monolayer formulated allows the designed biosensing interface to withstand harsh regeneration treatment, making it reusable.

Nanogold particle-enhanced oriented adsorption of antibody fragments for immunosensing platforms

“…1, where the initial modifications of n-butyl amine PPF and further assembly of nanogold particles on the surface of the QCMs were performed as described previously (Wang et al, 2003(Wang et al, , 2004. A portion of 30 l BF Ab fragment solution (1:40 titer, PBS of pH 7.4) was then dropped onto the nanogold particle-derivatized crystals, left at 4 • C overnight, then washed with PBS of pH 7.2 and dried in air.…”

“…On the one hand, nanogold particles, with unique physical and chemical features (Martin and Mitchell, 1998), should increase the surface loading density (amount) of the fragments with remained antigen binding activity. On the other hand, use of PPF as the sensing supports might have some outstanding advantages over the traditional films such as uniform structure, high mechanochemical stability, and good adhesion to substrate (Nakanishi et al, 1996;Muguruma and Karube, 1999;Wang et al, 2003Wang et al, , 2004. The assembly of nanogold particles on the functionalized PPF might produce a robust molecular adsorption matrix, and desirable sensor performances, i.e., operational stability and reusability, could be expected.…”

Adsorption of cobalt ferrite nanoparticles within layer-by-layer films: a kinetic study carried out using quartz crystal microbalance

“…37,49 This finding evidences a strong association between CoFe 2 O 4 nanoparticles and the substrate surface. Considering a model picture for the system in which all surface sites are occupied, with adsorbed nanoparticles forming a monolayer composed of a hexagonal close-packed arrangement of spheres, a simple calculation gives 2.0 Â 10 12 nanoparticles per cm 2 .…”

Simultaneous detection of five indices of hepatitis B based on an integrated automatic microfluidic device

“…Prior to the experiment, the working electrodes (10 µm in diameter) were polished carefully with abrasive paper, and then rinsed thoroughly twice with water, ultrasonicated in nitric acid (1:1), acetone and absolute ethanol for ten minutes, respectively. The cleaned electrodes were deposited with plasma-polymerized ethylenediamine film (PPF) according to the literature (Wang, 2003), and then immersed in the nanogold particle suspensions for 12 h at 4 • C. Following that, the five indices of hepatitis B were separately dropped onto the nanogold particle-functionalized surface (from working electrode 1 to working electrode 5 in Fig. 1, electrode 6 is a control drying in air), and left at 4 • C overnight (i.e.…”