Autonomous multielectrode system for monitoring the interactions of isoflavonoids with lung cancer cells.

The cytotoxic effect of isoflavonoids in the development of different forms of cancer has been reported by epidemiological and dietary studies. Consequently, there is a search for an accurate and reliable method for monitoring the interactions of these chemicals with cancerous cells. We have developed and optimized a fully autonomous electrochemical biosensor for studying the role of isoflavonoids on A549 lung adenocarcinoma cell line. This advanced biosensor uses a prototype 96-electrode (DOX-96) well-type device that allows the measurement of cell respiratory activity via the consumption of dissolved oxygen. The system provides a continuous, real-time monitoring of cell activity upon exposure to naturally occurring polyphenols, specifically resveratrol, genistein, and quercetin. The system is equipped with a multipotentiostat, a 96-electrode well for measurements and cell culturing with 3 disposable electrodes fitted into each well. A comparison with classical "cell culture" techniques indicates that the biosensor provides real-time measurement with no added reagents. A detection limit of 1 x 10(4) was recorded versus 200 and 6 x 10(3) cells/well for MTT and fluorescence assays, respectively. This method was optimized with respect to cell stability, reproducibility, applied potential, cell density per well, volume/composition of cell culture medium per well, and incubation. Others include total measuring time, temperature, and sterilization procedure. This study represents a basic research tool that may allow researchers to study the type, level, and specific influence of isoflavonoids on cells.