Quantifying neuron-specific enolase on TiO₂-goldurchin-modified electrodes for lung cancer diagnosis

This research was developed a neuron specific enolase (NSE) biosensor on titanium oxide (TiO₂) modified interdigitated microelectrodes (IDME). Biotin-streptavidin strategy was utilized to immobilize the aptamer on IDME. It was identified that higher number of streptavidin and aptamer complex captured on IDME when the surface modified with TiO₂ compared with a direct immobilization. The sandwich pattern with aptamer and antibody was performed on TiO₂-modified surfaces. The detection limit of NSE was identified as 0.1 ng/mL with an R² value of 0.9826 [y = 9.6984x-13.089]. To enhance the detection performance, the antibody was conjugated with goldurchin and it increases the current flow, detecting NSE-spiked serum as low as 0.1 ng/mL. Besides, control experiments with Interleukin-6, Carcinoembryonic antigen, and complementary aptamer sequence (a non-binding aptamer) fail to enhance the current responses. This NSE biosensor quantifies the lower level of target and helps to diagnose lung cancer and severity.