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Journal of Analytical & Bioanalytical Techniques | ISSN: 2155-9872 | Volume 9
World HPLC, Separation Techniques & Pharmacovigilance
World Analytical Chemistry & Mass Spectrometry
18
th
International Conference on
August 29-30, 2018 | Toronto, Canada
&
Biosensing approaches for lysozyme detection with graphene oxide-coated plasmonic interfaces
Alina Vasilescu
University of Bucharest, Romania
L
ysozyme is used as a model to study protein function and enzyme catalysis, is suggested as a biomarker in various diseases
and also used as an antimicrobial agent in the food industry. Various methods have been reported for lysozyme detection
based on its physicochemical properties, enzymatic activity or affinity for biological receptors. The aptasensors with detection
by Surface Plasmon Resonance (SPR) developed by our group are versatile tools for the detection of residual lysozyme in wines
or of lysozyme dimer in aggregated solutions. Advancing from these concepts relying on thiol coated plasmonic interfaces,
we report the development of graphene oxide (GO) coated plasmonic interfaces via the layer-by-layer method, as robust and
sensitive platforms with controlled thickness. Furthermore, the GO-coated interfaces were easily modified with whole cells of
Micrococcus lysodeikticus
- an enzymatic substrate for lysozyme. Detection of lysozyme in spiked serum samples was achieved
on the principle of lysozyme’s lytic action causing desorption of bacteria from the interfaces and consequently changes in the
SPR signal. The analysis time was 3 minutes and the detection limit was 3.5 nM. A second sensing concept exploited the affinity
of lysozyme for an aptamer, fixed covalently to the GO-coated interfaces. In this case, a detection limit of 0.71 nM and a linear
range of 2-21 nM were observed. The two analytical strategies are based on different sensing mechanisms, nonetheless, both
are sensitive and easy to implement with GO-coated interfaces suggesting a high potential and versatility of these interfaces
for bioanalytical purposes.
Biography
Alina Vasilescu has completed joint Ph.D. studies from the University of Bucharest, Romania and University of Perpignan, France and postdoctoral studies from
University of Toronto, Canada. She has worked in analytical development in the pharmaceutical industry and is currently a researcher at the International Centre of
Biodynamics in Bucharest, Romania working on practical applications of biosensors. She has published more than 30 papers in the field of biosensors.
avasilescu@biodyn.roAlina Vasilescu, J Anal Bioanal Tech 2018, Volume 9
DOI: 10.4172/2155-9872-C1-027