Highly sensitive and specific cytosensing of HT 29 colorectal cancer cells using folic acid functionalized-KCC-1 nanoparticles.

Functionalized fibrous nano-silica (KCC-1) was applied to specific electrochemical detection of HT 29 colorectal cancer cells based on folate (FA)/folate receptor (FR) interactions. KCC-1 fibrous materials were synthesized using a hydrothermal method and then functionalized with FA molecules to produce KCC-1-NH2-FA nanoparticles. The KCC-1-NH2-FA fibrous nanoparticles offer favorable bleaching stability and exceptional surface area-to-volume ratio which provide facility to design more sensitive cytosensors. The morphology, size and surface charge of KCC-1, KCC-1-NH2 and KCC-1-NH2-FA were approved by field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential, respectively. The porosity of the negatively charged KCC-1-NH2-FA was also tested with Brunauer-Emmett-Teller (BET) which approves the high surface area-to-volume ratio of the KCC-1 based materials. Flow cytometry and fluorescence imaging were applied to approve quantitative and qualitative attaching of KCC-1-NH2-FA to the HT 29 FR-positive cancer cells. Also, the specific capturing of the nanoparticles were approved by FR-negative HEK 293 normal cells as FR-negative cells through cellular uptake assay which showed the smart differentiation by KCC-1-NH2-FA nanomaterials. The cytotoxicity results revealed the biocompatible nature of KCC-1 based materials, implying that the developed method could be used in in vivo applications under the optimized conditions. The developed cytosensor response is linear from 50 to 1.2 × 104 cells/mL with a lower limit of detection (LLOQ) of 50 cells/mL. As advantage of the developed cytosensor is simple and provides excellent specificity and sensitivity which enables us to design point of care devices for clinical uses.