Colorectal Cancer Biosensor Using Vertically-Oriented Silicon Nanowires

For men and women combined, colorectal cancer is the second largest cause of cancer-related death in the United States [1]. To diagnose CRC and monitor its progression, it is crucial to detect its protein and circulating tumor DNA (ctDNA) biomarkers in liquid biopsy samples. Here, we report a vertically oriented silicon nanowire (vSiNW) biosensor for label-free detection of CRC. We demonstrate that appropriately functionalized SiNWs can detect clinically relevant concentrations of carcinoembryonic antigen (CEA, < 2.5 ng/mL), carbohydrate antigen 19–9 (CA19-9, < 37 U/mL), and BRAFV600E ctDNA mutation
$(< 11.2\mu \mathrm{M})$
.