Highly sensitive mixed molecular nanostructures of glutamine and doxorubicin on gold for targeted recognition of A2780 cancer cells using impedance spectroscopy and quartz crystal microbalance

Mixed molecular nanostructures, formed on the surface of gold, provide exceptional assemblies and display unique properties for different purposes, especially, recognition of biomolecules, drug delivery, and cancer cell sensing. In this study, a targeted molecular nanostructure system is prepared on gold, and studied for recognition of cancer cells. The system consists of doxorubicin (Dox), an effective anticancer chemotherapy agent but with cardiotoxicity side effect, and glutamine (Glu), a targeting agent with a potential to reduce the cardiotoxicity induced by Dox, immobilized adjacently on gold via mercaptopropionic acid linker. The preparation process is followed by several surface and solution analysis techniques, and the obtained system is characterized as Au-MPA-(Glu-parallel to-Dox). The ability of the system to recognize the Human Ovarian Carcinoma (A2780) cells is studied in comparison with Human Caucasian Foetal Foreskin Fibroblast (HFFF2) as nonmalignant cells using electrochemical impedance spectroscopy (EIS) and quartz crystal microbalance (QCM) as transaction methods. The system has shown a rapid uptake kinetics (t(1/2)similar to 7.7 +/- 0.1 min) for A2780 cells. The Au-MPA-(Glu-parallel to-Dox) system showed high sensitivity in recognition of the A2780 cancer cells (Delta R-ct of similar to 1430 +/- 43.0 k Omega and Delta f of similar to 2500 +/- 18 Hz for 5 x 10(5) cell/mL of A2780 cells).