Oligonucleotide and aptamer derivatized surfaces in potentiometric sensors preliminary results

DEVIN DAEMS; FERNÁNDEZ, MARCELO R.; BERNIK, DELIA L.; KAROLIEN DE WAEL; LUC J. NAGELS; GUY VAN CAMP

Łochów

Workshop; Surface Modification for Chemical and Biochemical Sensing 2011 International Workshop; 2011

Polish Supramolecular Chemistry Network Foundation

In genetic molecular diagnostics there is a big need for instruments to detect different DNA variations and mutations selectively and fast to diagnose the human genetic disorders. The current methods are usually based on fluorescence. They are often expensive and time-consuming and in addition they are not always appropriate for high throughput multiplex analysis. Amperometric DNA sensors are in the scientific research stage. Potentiometric DNA sensors have been investigated much less in this respect. In the present study, oligonucleotides and aptamers were covalently coupled to  carboxylated PVC based potentiometric sensor coatings. Oligonucleotides are multiply charged molecules which we found earlier to have unexpectedly good detectability on non-selective anion sensitive sensors. Aminated DNA was coupled to a carboxylated PVC membrane. On the attached figure we see a blank membrane on the left (negative control), a membrane with covalently coupled aminated DNA with fluorophore (Cy3) in the middle (positive control) and a membrane with covalently coupled aminated DNA on the right (experiment). The complementary DNA with fluorophore (Cy3) was added to hybridize in 0,01M MES to each membrane. The hybridization was checked with a confocal microscope. We already investigated the effect of sensor kinetics and sensor response for e.g. dopamine selective aptamer based sensors and compared it to the behavior of non-derivatized sensors.