CHLOROPHYLL a IMMOBILIZATION INTO TETHERED BILAYER LIPID MEMBRANE

Viktorija Liustrovaite1, Ausra Valiuniene1, Gintaras Valincius2, Arunas Ramanavicius1, 3

1 Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Vilnius, Lithuania

2 Centre for Natural Sciences, Vilnius University, Vilnius, Lithuania

3 Laboratory of Nanotechnology, State Research Institute Center for Physical Sciences and Technology, Vilnius, Lithuania

[email protected]

Chlorophyll (Chl-a) is a special $\pi$-$\pi$-conjugated structure situated around its macrocyclic skeleton, and the variety of side groups around it allows all photosynthetic species to serve as a major photoactive and structural part [1]. Chl-a has been created by evolution to interact with light and is responsible for absorbing the sun photons and converting their energy into chemical bond energy in a shape that is open to nearly all life forms [2]. It is believed that chlorophyll is in the cell plasma membrane, which means that the area between the cell outer and inner medium is divided, and its nature and arrangement are providing a shape to the cell [3]. The tethered bilayer lipid membrane (tBLM) is a complex system that can be used as an experimental platform for fundamental studies of the structure and function of the bio membrane. In this work, one of such models, tBLM on the gold surface are formed by using the fusion of vesicles [4]. This immobilized membrane alteration enables different biosensors to be produced by adding lipid components such as DOPC (1,2-dioleoyl-sn-glycero-3-phosphatidylcholine) and cholesterol [5], having stability which can be modified by adding molecules such as chlorophyll a (Chl-a).

The aim of this study is to create phospholipid bilayer model with immobilized Chl-a. The investigation is performed with electrochemical impedance spectroscopy (EIS) to measure dielectric capacity and conductivity changes. Fluorescence microscopy (FM) is used to estimate the morphology of the membranes. The goal of this research is to explore the effectiveness of incorporating the photoactive compound Chl-a into the tethered bilayer lipid membrane in order to build a platform that could be used in the future for the development of photosensitive surface structures based on tBLM that could theoretically be used for the development of new biomimetic artificial leaves and biosensors.


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