The study of surface properties of an IgE-sensitive aptasensor using an acoustic method

Abstract

We applied the acoustic transverse shear mode (TSM) method for study of the surface properties of a DNA aptasensor that specifically binds human immunoglobulin E (IgE). The biotinylated 45-mer DNA aptamers were immobilized on the surface of a self-assembled layer composed of a mixture of polyamidoamine dendrimers of the fourth generation with 1-hexadecanetiol covered by neutravidin. Using the TSM method, we studied the kinetics of changes of the series resonant frequency, f(s), and the motional resistance, R(m), of a quartz crystal transducer, used as a support for formation of the sensing layer. We have shown that attachment of the biotinylated DNA aptamers onto the surface covered by neutravidin results in a decrease of f(s), but in an increase of R(m). Similar changes of f(s) and R(m) were observed following addition of IgE. This suggests the contribution of friction forces to the crystal oscillation, which was taken into account in the calculation of the mass changes at the sensor surface following binding processes.

Aptamer‐Based Label‐Free Immunosensors Using Carbon Nanotube Field‐Effect Transistors

“…Gokulrangen et al have reported an aptamer-based bioanalysis for IgE detection using fluorescence anisotropy [54], and obtained a limit of detection of 350 pM. Moreover, Snejdarkove et al have studied surface properties of an IgE-sensitive aptasenosr using an acoustic method [55]. In our study, we detected IgE in the range of 250 pM -160 nM using aptamer-based CNTFETs, indicating that CNTFETs are useful for detecting proteins such as IgE.…”

Electrochemical Aptasensors – Recent Achievements and Perspectives

“…QCM method allowing also the determination of the number of IgE bounded to the surface. However, as we have shown in our recent paper [19], the changes of the frequency due to the binding of IgE to DNA aptamers immobilized at the surface of quartz crystal are only partially connected with the changes of the mass. For correct detection of the surface concentration of IgE it is necessary to take into consideration also the viscous forces, that may be determined by measuring so called motional resistance, R m .…”

“…Using glutaraldehyde, crosslinking of avidin to a dendrimer surface is possible, so it can be then used for immobilization of biotinylated aptamers. The advantage of dendrimers is their high stability and relatively large surface in comparison with flat electrode [57,61]. So et al [16] reported immobilization of thrombin aptamer onto the surface of carbon nanotubes.…”

“…This highly promising direction is currently of considerable focus. It is also highly advantageous to explore the possibility of immobilization of aptamers onto novel materials, such as carbon nanotubes [16 -18] or dendrimers [19], and using nanoparticles [20] and quantum dots [21] in detection of the ligand -aptamer interactions.…”

Detection of Abasic Sites in DNA by Electrochemical, Immunoelectrochemical and Acoustic Methods Using OsO4, 2,2′‐bipyridine as a Probe for Unpaired Thymine Residues

“…The values of these parameters reflect the conditions at the interface with respect to mass and interfacial properties [21]. A network analyzer (8712ES Network/Spectrum analyzer, Agilent Technology, USA) was used to determine f S and R m values (see [22] for more details). All experiments were performed at temperature 20 AE 1 8C.…”