Direct, Rapid, and Label-Free Detection of Enzyme Substrate Interactions in Physiological Buffers Using CMOS-Compatible Nanoribbon Sensors

We demonstrate the versatility of Al2O3-passivated Si nanowire devices (nanoribbons) in the analysis of enzymesubstrate interactions via the monitoring of pH change. Our approach is shown to be effective through the detection of urea in phosphate buffered saline (PBS), and penicillinase in PBS and urine, at limits of detection of <200 mu M and 0.02 units/mL, respectively. The ability to extract accurate enzyme kinetics and the MichaelisMenten constant (K-m) from the acetylcholineacetylcholinesterase reaction is also demonstrated.