Fig. 5

Release of CS-ODN attached to pristine or functionalized MWCNT. Depicted is the amount of released CS-ODN following a adsorption or b covalent binding with and without prior activation to pristine or modified MWCNT. The initial concentration of the 6-FAM-labeled CS-ODN was 10 nmol/mg_CNT and the released amount was determined by fluorescence measurements in the supernatant of the binding reaction, in the washing solution (twice with PBS) and in the release solution (in PBS at 80 °C for 2 × 10 min). The specific activation procedures prior to the covalent binding were as follows: NH₂-CS-ODN coupled to MWCNT-COOH activated with EDC/NHS, DSS-activated NH₂-CS-ODN coupled to MWCNT-NH₂, maleimide-activated CS-ODN coupled to MWCNT-SH. Control experiments were performed without specific activation