Aptamer and sodium alginate decorated graphene oxide composite material with ion responsiveness for Low-density lipoprotein trapping.

The accumulation of excess Low-density lipoprotein (LDL) is strongly associated with the occurrence of heart failure, coronary artery disease and hypercholesterolaemia, and is a major factor in cardiovascular and cerebrovascular disease. Concerns about the ways to decrease LDL level have continuously arisen. In this study, an ionic stimulation-responsive composite (i.e., GO@Apt@SA) is prepared with modification of graphene oxide (GO) utilising LDL-aptamer (Apt) and sodium alginate (SA). The ion-responsive behaviour of GO@Apt@SA synergistically interacts with the specific recognition property of the aptamer, enabling adsorption of LDL with higher capacity and specificity. Under the optimal experimental conditions, the maximum adsorption capacity of GO@Apt@SA for LDL is 730.6 μg mg-1. Interestingly, the aptamer complementary chain could trigger the release of LDL with favourable elution efficiency, which competitively binds with LDL-specific aptamer to trigger LDL release. More importantly, GO@Apt@SA exhibits satisfactory adsorption performances for LDL in goat serum, meaning that the composite material and technology are available for the extraction of LDL from complex sample matrices.