Cyclic voltammetric biosensing of cellular ionic secretion based on silicon nanowires to detect the effect of paclitaxel on breast normal and cancer cells

Cell-free analysis based on environmental secretions of the cells/tissues, such as point of care testing, is a rapidly evolving area with advances in integrating sample handling, cheap fabrication, and easy operation. Also, they could be used as complementary cell-based analysis without inducing any perturbation on standard assays. Here, we present a secretion-based cyclic voltammetry biosensor with the assistance of silicon nanowire electrodes to detect ionic concentration changes in the secretions of breast normal and cancer cell lines after being treated by Paclitaxel drug. Changes in CV peaks of the secretions showed a meaningful correlation with the levels of apoptosis after drug treatment in both healthy and malignant cells. Such changes were sharper in MDA-MB-231 than MCF-10A cell lines. This platform could be applied as a cell-free apoptosis sensor to monitor the drug resistance of cancer cells. The sensor is not single used and could be re-used by a simple rinse protocol.