title: Fiber loop ringdown DNA and bacteria sensors.
abstract: We report a new type of refractive index-based biosensor using a fiber loop ringdown evanescent field (FLRD-EF) sensing scheme, in which the sensing signal is a time constant and detection sensitivity is enhanced by the multipass nature of the ringdown technique. Bulk index-based detections of three different single strand DNAs and one type of bacteria are demonstrated for the FLRD-EF sensors that utilize a partially-etched single mode fiber as the sensor head. Stepwise coating of the sensor head with poly-L-lysine and a probe DNA has enabled surface index-based label-free target DNA sensing. We expect an array of FLRD-EF biosensors to be created, which are superior to counterparts in terms of simplicity, low cost, and high sensitivity.
authors.affiliation: Department of Physics and Astronomy and the Energy Institute, Mississippi State University, Mississippi State, Mississippi 39762 , USA.
authors.forename: Chamini
authors.initials: C
authors.lastname: Herath
authors.forename: Chuji
authors.initials: C
authors.lastname: Wang
authors.forename: Malik
authors.initials: M
authors.lastname: Kaya
authors.forename: David
authors.initials: D
authors.lastname: Chevalier
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000302:isolation & purification*; D015374:Biosensing Techniques / Q000295:instrumentation*; D004269:DNA, Bacterial / Q000032:analysis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D010783:Photometry / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D014159:Transducers
chemical_list: D004269:DNA, Bacterial