Investigating the Kinetics of Antibody Adsorption onto Polyethylene Terephthalat (PET) Modified with Gold Nanoparticles in Flow Microchannel

Abstract

The real-time monitoring of the adsorption kinetic of antibody onto polyethylene terephthalate (PET) modified with gold nanoparticles (NPs) is performed into a dielectric flow microchannel. The principle is based on the microelectrode-dielectric interface excitation by a modulated voltage excitation through the dielectric layer with high frequency range. The set-up configuration using a homemade current-to-voltage converter has been developed for fast monitoring of biomolecule adsorption without direct electrical contact of microelectrodes with the microchannel flow. The change in the interfacial admittance, related to the output voltage measured through the microchip, during antibody incubation, gives information on the kinetics involved while antibodies are adsorbed at the interface. An example of adsorption on PET modified with gold NPS was taken. Experimental data were fit with the Langmuir equation and a good correlation was obtained with this latter, where the equilibrium constant, K, was found as 1.55 × 10 8 M −1 with a limit of detection for antibody concentration without depletion equal to 8.25 nM.

Microchannel conductivity measurements in microchip for on line monitoring of dephosphorylation rates of organic phosphates using paramagnetic-beads linked alkaline phosphatase

“…In previous work alpha α int was found equal to 0.5 and Q int ¼4.7 Â 10 À 8 Ω À 1 s À α [29]. The change on the interfacial CPE parameter is neglected to the aim of this paper as the organic phosphate dephosphorylation occurs on Alcaline Phosphatase linked beads and not on the PET photoablated surface [31,32,36].…”

(Invited) An Improved the Impedance Spectroscopy Measurements with Non-Contact Microelectrodes Embedded into a Flexible Polymer Comprising a Microfluidic Network

“…This procedure enables a clear observation of the impedance of the solution in the microchannel associated in series with the interfacial impedance (PET/ solution interface). Indeed, this procedure enables new applications such as contactless conductivity in the high-frequencies (5), (6) and conversely, in the low-frequencies the monitoring the interfacial impedance change onto polymer where PET surface charge state depends on the chemical surface modification ( 7),( 8), (9).…”