Au-NPs signal amplification ultra-sensitivity optical microfiber interferometric biosensor.

An optical microfiber interferometric biosensor for the low concentration detection of sequence-specific deoxyribonucleic acid (DNA) based on signal amplification technology via oligonucleotides linked to gold nanoparticles (Au-NPs) is proposed and experimentally analyzed. The sensor uses a "sandwich" detection strategy, in which capture probe DNA (DNA-c) is immobilized on the surface of the optical microfiber interferometer, the reporter probe DNA (DNA-r) is immobilized on the surface of Au-NPs, and the DNA-c and DNA-r are hybridized to the target probe DNA (DNA-t) in a sandwich arrangement. The dynamic detection of the DNA-t was found to range from 1.

Development of an optical microfiber immunosensor for prostate specific antigen analysis using a high-order-diffraction long period grating.

Fiber-optic biosensors are of great interest to many bio/chemical sensing applications. In this study, we demonstrate a high-order-diffraction long period grating (HOD-LPG) for the detection of prostate specific antigen (PSA). A HOD-LPG with a period number of less than ten and an elongated grating pitch could realize a temperature-insensitive and bending-independent biosensor.