engleski

Adhesion based detection of organic microparticles in aquatic systems

The organic micropartices in aquatic systems (organic droplets, vesicles and cells with fluid membrane) can be characterized through appearance of the well-defined amperometric signals at the mercury electrode (1-3). Mercury electrode serves as adhesion based sensor where interfacial properties could be controlled by changing of applied potential. Adhesion and spreading of a soft organic particle at a charged mercury/water interface causes double-layer charge displacement from the inner Helmholtz plane, and the transient flow of compensating current can be recorded as an amperometric signal. We have interpreted amperometric signal of individual particle on kinetical and mechanical level using two independent models, where extracted complementary information are important for better understanding of adhesion mechanism (4). Further, adhesion based detection is sensitive to polar head groups in phospholipids vesicles. We have identified a narrow potential window around the point of zero charge of electrode where the interaction of polar head groups of lipid vesicles with the substrate is manifested in the form of specific bidirectional signals (5). References 1.V. Žutić, S. Kovač, J. Tomaić, V. Svetličić, Heterocoalescence between dispersed organic microdroplets and a charged conductive interface, J. Electroanal. Chem. 349 (1993) 173-186. 2. V.Svetličić, N. Ivošević, S. Kovač, V. Žutić, Charge displacement by adhesion and spreading of a cell: Amperometric signals of living cells, Langmuir 16 (2000) 8217-8220. 3. N. Ivošević DeNardis, V. Žutić, V. Svetličić, R. Frkanec, J. Tomašić, In situ amperometric characterization of liposome suspensions with concomitant oxygen reduction, Electroanal. 19 (2007) 2444-2450. 4. N. Ivošević DeNardis, I. Ružić, J. Pečar-Ilić, S. El Shawish, P. Ziherl, Reaction kinetics and mechanical models of liposome adhesion at charged interface. Bioelectrochemistry 88 (2012) 48–56. 5. N. Ivošević DeNardis, V. Žutić, V. Svetličić, R. Frkanec, Adhesion signals of phospholipid vesicles at an electrified interface, J. Membr. Biol. 2012, DOI: 10.1007/s00232-012-9469-8.

adhesion; chronoamperoemtry; organic microparticles; aquatic system

nije evidentirano