Lablog4-38：Preparation of scFv-immobilized quartz crystal microbalance sensor by PS-tag-mediated solid-phase refolding

Abstract

 The activation of a single-chain Fv antibody on the surface of a quartz crystal microbalance (QCM) sensor chip was investigated in order to develop an economical and sensitive immuno-QCM sensor system for use in clinical diagnosis. On the bare gold surface of a QCM sensor chip, approximately 60 nm of hydrophilic polystyrene (phi-PS) thin film that specifically binds the polystyrene-binding peptide (PS-tag) was prepared by spin-coating and O2-plasma irradiation. When the adsorption of PS-tag-fused anti-ED-B scFv (scFv-PS) onto the phi-PS surface was directly monitored, the maximum density of scFv-PS attained was 1.56 μg/cm2, 1.6-times higher than that of scFv. The specific antigen-binding activity of scFv-PS after solid-phase refolding increased with the density of immobilized scFv-PS, and, consequently, activity 1.7 times higher than that of scFv was retained. The scFv-PS-immobilized QCM sensor chip rapidly allowed the detection of clear signals for antigen at the range of 0.1–10 μg/ml, while no signal was detectable for 10 μg/ml BSA as a negative control. The scFv-PS-immobilized QCM sensor developed in the present study will therefore be very useful for the rapid and highly sensitive detection of biomarkers, and should be applicable to clinical diagnosis.

DOI https://doi.org/10.1016/j.jbiosc.2010.12.005