DOPC LIPOSOMES AS POTENTIAL LABELS FOR GENETICALLY MODIFIED ORGANISM DETECTION ASSAY DEVELOPMENT.

FARIAS MARCOS E.; LUNA M ALEJANDRA ; CORREA N MARIANO ; MOLINA PATRICIA G; NIEBYLSKI ANA M

Villa de Merlo

Congreso; XXXV Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2017

SOCIEDAD DE BIOLOGIA DE CUYO

Genetically modified organisms (GMO) detection has acquired great interest in food safety studies. In this regard, immunosenors, based on antigen-antibody interaction, have aroused interest due to their specificity and low detection limit. To improve sensitivity, liposomes are being used as labels because of their ability to encapsulate different molecules, allowing to amplified detection signals. In this work, we studied the 1,2-di-oleoyl-sn-glycero-3-phosphatidylcholine (DOPC) vesicles ability to encapsulate potassium ferrocyanide (K4(Fe(CN)6), to be used as labels in GMO immunosensors development. Vesicles of a size of 193.2 ± 0.75 nm were obtained. K4(Fe(CN)6 was released for electrochemical detection by adding Triton X-100. The average electrical charge from different vesicles aliquots was 2.79 ± 0.1x10-6 C, which demonstrated that all vesicles incorporated approximately the same molecules number. On the other hand, the leakage percent was determined to be 25% after storage for 30 days. In order to increase stability, the vesicles lyophilization was probed, using cholesterol and disaccharides as lyoprotectants. Transmission electron microscopy images did not show structural differences between lyophilized and non-liophylized vesicles. In addition, lyophilized vesicles maintained the electrochemical response, these results suggest that lyophilization could be used for increasing vesicles stability in time. A calibration curve was performed using differents concentrations of these vesicles. The peaks currents obtained showed linear dependence (R=0.992) with the increase of the vesicles concentration. On the other hand, the vesicles were successfully attached to proteins. According to these results, DOPC vesicles could be utilized as signal amplifiers in electrochemical immunosensors for GMO detection in food.