doi:10.1016/j.bios.2006.03.010
Copyright © 2006 Elsevier B.V. All rights reserved.
Registration of T-2 mycotoxin with total internal reflection ellipsometry and QCM impedance methods
References and further reading may be available for this article. To view references and further reading you must
purchase this article.
A.V. Naboka, 
, 
, A. Tsargorodskayaa, A. Hollowaya, N.F. Starodubb and O. Gojsterb
aSheffield Hallam University, Materials and Engineering Research Institute, City Campus, Pond Street, Sheffield S1 1WB, UK
bPalladin Institute of Biochemistry, National Academy of Sciences of the Ukraine, Kiev 02030, Ukraine
Received 31 January 2006;
accepted 9 March 2006.
Available online 19 April 2006.
Abstract
A sensitive optical method of total internal reflection ellipsometry (TIRE) in conjunction with immune assay approach was exploited for the registration of T-2 mycotoxin in a wide range of concentrations from 100 μg/ml down to 0.15 ng/ml. Association constants of 1.4 × 106 and 1.9 × 107 mol−1 s for poly- and monoclonal T-2 antibodies, respectively, were evaluated from TIRE kinetic measurements. According to TIRE data fitting, binding of T-2 molecules to antibodies (at saturation) has resulted in the increase in adsorbed layer thickness of 4–5 nm. The QCM impedance measurements data showed anomalously large mass increase and film softening, most likely, due to the binding of large T-2 aggregates to antibodies.
Keywords: T-2 mycotoxin; Immune assay; Spectroscopic ellipsometry; Total internal reflection; Surface plasmon resonance (SPR); QCM impedance spectroscopy
Fig. 1. Typical TIRE spectra of Ψ and Δ measured on bare Cr/Au coating on glass. The cross on the Ψ(λ) spectrum indicates the choice of wavelength for kinetics measurements. The inset shows TIRE measurements scheme, where the polarized light is coupled through a 68° prism (1); into Cr/Au coated glass slide (2); the reaction cell (3) having inlet and outlet tubes is sealed to the sample via rubber O-ring.
Fig. 2. A typical set of Δ(λ) spectra for initial bare Cr/Au surface (1), after consecutive adsorption steps of PAH (2), Protein A (3), mono-AB (4), and after binding of T-2 mycotoxin from solutions of different concentrations in ng/ml: 0.15 (5), 1.5 (6), 7.5 (7), 75 (8) and 300 (9).
Fig. 3. Changes in the adsorption layer thickness caused by T-2 mycotoxin binding vs. T-2 concentration in solution. The data for both poly- and mono-AB are presented.
Fig. 4. Typical kinetics of response in the course of binding T-2 mycotoxin to mono-AB and poly-AB. The inset shows the experimental points and fitting graphs (with equations) of S = kaC + kd vs. concentration (C) of T-2 mycotoxin for mono-AB and poly-AB.
Fig. 5. The dependence of Δf and ΔR on the concentration of T-2 mycotoxin. The inset shows admittance spectra of quartz crystals: uncoated (1), after adsorption of PAH/Protein A/Poly-AB (2), and after binding of T-2 mycotoxin of different concentrations in mg/ml: 1.5 (3), 7.5 (4), 30 (5), 150 (6), 600 (7) and 3000 (8).
Table 1.
Parameters of four-layer model in TIRE fitting
Parameters indicated with asterisk (*) were fixed during fitting.
Corresponding author. Tel.: +44 114 2253512; fax: +44 114 2253433.
Abstract
Purchase PDF (449 K)
E-mail Article
Add to my Quick Links
Cited By in Scopus (5)
Purchase PDF (92 K)
4.5 mg/kg) and at least 20 times more toxic than dermal administration (LD50 > 10 mg/kg).
