Fiber loop ringdown DNA and bacteria sensors

摘要

We report a new type of refractive index-basednbiosensor using a fiber loop ringdown evanescent fieldn(FLRD-EF) sensing scheme, in which the sensing signalnis a time constant and detection sensitivity is enhancednby the multipass nature of the ringdown technique. Bulknindex-based detections of three different single strandnDNAs and one type of bacteria are demonstrated for thenFLRD-EF sensors that utilize a partially-etched single modenfiber as the sensor head. Stepwise coating of the sensornhead with poly-L-lysine and a probe DNA has enablednsurface index-based label-free target DNA sensing. Wenexpect an array of FLRD-EF biosensors to be created, whichnare superior to counterparts in terms of simplicity, low cost,nand high sensitivity