Targeting and sensing of some cancer cells using folate bioreceptor functionalized nitrogen-doped graphene quantum dots.

In recent years, study of folate receptor (FR) expression related to targeting, drug delivery and counting of tumoral cells have been followed. In this work, a fast and simple strategy was reported to determine the FR expressed cancer cells based on the selective bonding of the folic acid/folate (FA) to the FR-positive tumor cells. The folate decorated Nitrogen-doped graphene quantum dots (N-GQDs) were utilized as selective targeting of the MKN 45 cells. Fluorescent microscopy imaging investigations revealed that the produced FA conjugated N-GQDs could specifically attach to the target FR-positive tumor cells. Due to the fluorescence emission of N-GQDs, the developed cytosensor is free from attaching any fluorescent ligand i.e. Rhodamine B to capture the florescence microscopy images and also flow cytometry analysis. The fabricated cytosensor possesses a dynamic range from 100 to 7.0 × 104 cell·mL-1 with high selectivity. Furthermore, the cytosensor also could visualized the MCF 7 and HT 29 cells where the dynamic ranges were 100 to 1.0 × 104 and 500 to 4.0 × 104 cells·mL-1, respectively. In vitro toxicity tests has shown low toxicity of the synthesized N-GQDs where the minimum viability is 68%. The proposed FA-N-GQDs based cytosensor provides a novel platform for detection of MKN 45, HT 29 and MCF 7 cancer cell lines which could be used in multi-channel cancer diagnosis biodevice.