Reflectometric interference microchip based on nanoporous alumina for label-free detection of circulating tumour cells

Abstract

Circulating tumor cells (CTCs) are defined as circulating tumor cells in the peripheral blood that shed from either the primary tumors or its metastases. In this study, we aim to materialize a new real-time, label-free microchip biosensor for detection of circulating tumour cells (CTC) based on reflectometric interference spectroscopy (RIfS) on nanoporous anodic aluminium oxide (AAO). Biotinylated human anti-EpCAM antibody that specifically binds to cancer cells of epithelial origin was covalently immobilized on Au modified AAO substrate by applying streptavidin-biotin interactions. Pancreatic Cancer cells (PANC-1) were spiked into PBS buffer as well as whole blood samples without pre-labelling were captured and detected by specially designed RIfS microchip device. Our preliminary results show capability of developed device to highly selectively measure the concentration of cancer cells from 1000 to 200.000 cells/ml in buffer solution and blood samples with response time <5 minutes and volume of sample of 50 μl.