title: Determination of bacterial activity by use of an evanescent-wave fiber-optic sensor.
abstract: A novel technique based on fiber-optic evanescent-wave spectroscopy is proposed for the detection of bacterial activity in human saliva. The sensor determines th e specific concentration of Streptococcus mutans in saliva, which is a major causative factor in dental caries. In this design, one prepares the fiber-optic bacterial sensor by replacing a portion of the cladding region of a multimode fiber with a dye-encapsulated xerogel, using the solgel technique. The exponential decay of the evanescent wave at the core-cladding interface of a multimode fiber is utilized for the determination of bacterial activity in saliva. The acidogenic profile of Streptococcus mutans is estimated by use of evanescent-waveabsorption spectra at various levels of bacterial activity.
authors.affiliation: School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798.
authors.forename: M Shelly
authors.initials: MS
authors.lastname: John
authors.forename: Anil
authors.initials: A
authors.lastname: Kishen
authors.forename: Lim Chu
authors.initials: LC
authors.lastname: Sing
authors.forename: Anand
authors.initials: A
authors.lastname: Asundi
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D004867:Equipment Design; D005336:Fiber Optic Technology / Q000379:methods*; D006801:Humans; D055100:Optical Fibers; D012463:Saliva / Q000382:microbiology*; D013053:Spectrophotometry / Q000379:methods*; D013295:Streptococcus mutans / Q000302:isolation & purification*