Detection of human lung carcinoma cell using quartz crystal microbalance amplified by enlarging Au nanoparticles in vitro

A new amplification route for human lung carcinoma cell detection based on the detection of gold deposition on an Au-antibody conjugate label acting as a “seeding” catalyst is reported. Quartz crystal microbalance (QCM) was employed to measure the catalyzed deposition of gold on the piezoelectric crystals. The gold-coated quartz crystal was modified by polystyrene films, which provided a substrate for antibody immobilization by physical adsorption. Atomic force microscopy (AFM) was used to evaluate the morphologies and smoothness of the polystyrene films obtained by dip coating. The polystyrene films significantly improve the surface smoothness of the electrode. Compared to the conventional Enzymelinked Immunosorbent Assay (ELISA), the method described herein is a less time consuming procedure and gives comparable detection sensitivity of human lung carcinoma cells, ca. 100 cells mL−1. This will be of great significance in the diagnosis of this disease.