Biomedical subjects

M V Voinova

Publications and source records attributed to M V Voinova.

3 recordsLinked to original sources

PubMed2006

Mechanically mediated electron transfer in model metallo-enzyme interfaces.

In this paper, we develop a physical analysis of charge transfer in the model 'metallo-enzyme' complex which consists of a synthetic redox-addressed assembly (a 'reaction center') hybridized with a quantum dot (a gold nanoparticle) and attached via molecular bridge (a spacer) to the electrode. This artificial system allows us to model electronic transduction in experimental redox ezyme-gold nanoparticle hybrid structure recently reported by Xiao et al. [Xiao, Y., Patolsky, F., Katz, E., Hainfeid, J.F., Willner, I., 2003. Science 299, 1877-1881]. We consider a photosensitive spacer that allows us to control the conductivity of the bridge by light. In this paper we will focus on a special type of nanoelectro-mechanical processes in this system and investigate single electronic effects in there.

Biosensing Techniques↗

PubMed2004

Electronic transduction in model enzyme sensors assisted by a photoisomerizable azo-polymer.

We develop a stochastic model of electronic transduction by means of a rod-like azo-polymer (single peptide molecule doped with a given amount of azo-benzene structural units) in polymer-redox enzyme biosensor. We propose a configuration where the azo-polymer is anchored next to the enzyme reaction center and functions as a light-driven micromechanical actuator shuttling electrons toward the electrode. We show that the output catalytic current is exponentially sensitive to variations in geometrical size of the polymer (a 'switch off' effect) and suggest a scheme where the switching effect is triggered by polymer photoisomerization, resulting in its overall length change.

Biosensing Techniques↗

PubMed2002

Missing mass effect in biosensor's QCM applications.

Nowadays, liquid applications of quartz crystal microbalance (QCM) opened a way for in situ studies of proteins, vesicles and cells adsorbed from the solution onto the QCM surface. The sensitivity of QCM to the viscoelasticity of the adsorbed biomaterial can be a reason of the experimentally observed deviation from a linear dependence of QCM resonant frequency on mass deposition (the so-called Sauerbrey relation) and can limit its application for biosensoring. Presented here rigorous theoretical analysis explains the deviation from ideal mass response of soft overlayers in the contact with liquid. The fundamental result of the theory is the analog of Sauerbrey relation for layered viscous/viscoelastic medium which can be exploited for the correct physical interpretation of QCM experimental data in biofluids, in particular for measurements of the 'true' surface mass of adsorbed biomolecular films. We predict a new physical effect 'missing mass' of the sample in liquid phase measurements and compare the results given by our theory with QCM measurements on supported membranes.

Adsorption↗