Ultrasensitive and Multiple Biomarker Discrimination for Alzheimer's Disease via Plasmonic & Microfluidic Sensing Technologies.

As the population ages, the worldwide prevalence of Alzheimer's disease (AD) as the most common dementia in the elderly is increasing dramatically. However, a long-term challenge is to achieve rapid and accurate early diagnosis of AD by detecting hallmarks such as amyloid beta (Aβ). Here, a multi-channel microfluidic-based plasmonic fiber-optic biosensing platform is established for simultaneous detection and differentiation of multiple AD biomarkers.

In situ surface turbidity sensor based on localized light scattering from tilted fiber Bragg gratings.

We propose a compact fiber-optic sensor for in situ and continuous turbidity monitoring, based on surface optical scattering of polarized evanescent waves from targeted particles. The sensor is composed of a tilted fiber Bragg grating (TFBG) packaged inside a microfluidic capillary. The transmission spectrum of the TFBG provides a fine comb of narrow cladding resonances that are highly sensitive to the turbidity due to the localized light scattering of polarized evanescent waves from the microparticles near the fiber surface (as opposed to traditional bulk/volumetric turbidity measurement).

Simultaneous measurement of the BOD concentration and temperature based on a tapered microfiber for water pollution monitoring.

An optical sensor that simultaneously measures the concentration of the biochemical oxygen demand (BOD) and temperature in water based on a tapered microfiber is proposed for environmental monitoring. The sensor is characterized by a strong evanescent field, which is more sensitive to liquids with a low refractive index and a low transmission loss. The results show that as the BOD concentration increases, the interference spectrum shifts toward longer wavelengths, the spectral loss decreases, and the sensitivities of the BOD are 12.

Microfiber coupler with a Sagnac loop for water pollution detection.

The measurement of chloride ion concentrations has been studied for the purpose of monitoring the quality of water resources. In this paper, a chloride ion sensor based on a microfiber coupler with a Sagnac loop is proposed. The microfiber coupler, which acts as the sensing unit and has a diameter of 10 μm and a length of 1 mm, is fabricated using the flame-brushing technique, and the two ends are connected to form a Sagnac loop, which acts as a reflector to enhance the reflection in the structure.