In the present study, we aimed to develop stable and brain cancer targeted superparamagnetic iron oxide (SPION), which was functionalized with APTES ((3-Aminopropyl) triethoxysilane) and polyethylene glycol (PEG) to improve its structural, spectroscopic, morphological, and magnetic properties were analyzed by XRD (X-ray powder diffraction), FT-IR (Fourier transform infrared), SEM (Scanning electron microscopy), TEM (Transmission electron microscopy), TGA (Thermal gravimetric analysis) and VSM (Vibrating sample magnetometer) respectively. Then it was conjugated with Folic acid (FA) as targeted brain cancer cell lines and Carboxylate Quercetin (CQ) as anticancer drug. Cellular uptake of SPION@APTES@FA-PEG@CQ nanodrug and its Quercetin release were determined by Prussian blue staining and fluorescence spectroscopy respectively. Additionally, its cytotoxic effects on L929 (fibroblast cells, which are folic acid receptors negative cells) and U87 (brain adenocarcinoma, which are folic acid receptors overexpressed) cell lines were studied by MTT ((3-(4,5-dimethylthiahiazol-2-yl)-2,5-diphenyl tetrazolium)) assay. It was found out that SPION@APTES@FA-PEG@CQ nanodrug enters into the cells and from which quercetin was released under acidic conditions in vitro. SPION@APTES@FA-PEG (0–200µg/ml) was not cytotoxic whereas SPION@APTES@FA-PEG@CQ nanodrug has decreased the cell viability on U87 cell lines according to MTT assay. Newly synthesized SPION@APTES@FA-PEG@CQ nanodrug has a great potential for the treatment of brain adenocarcinoma. In vivo and in vitro hyperthermia applications (due to magnetic properties) of this nanodrug is currently under progress and will be published soon.