Trapping-assisted nanopore sensing of molecular biomarkers

Integrated nanopore sensors enable label-free electrical detection of single molecular biomarkers using modulations in ionic current across a nanoscale opening in a solid-state membrane. Optical trapping can dramatically increase the rate of molecular detection and, thus, significantly speed up the sensing process. This is accomplished by optical delivery of microbeads that carry molecular targets that are specifically bound to their surface. Once trapped at the nanopore location, targets are released from the carrier bead and drawn through the pore by the large electric field that is present right at the pore location. We review the principle and implementation of this approach on an optofluidic chip. We report over 1000x improvement in sensing time and the application of these devices to detection of different molecular biomarkers and for infectious disease diagnosis of clinical samples.