Fast Tunable Biological Fluorescence Detection Device with Integrable Liquid Crystal Filter

Abstract

Detecting a variety of biological samples accurately and swiftly in an integrated way is of great practical significance. Currently, biofluorescent spectrum detection still largely relies on microscopic spectrometers. In this study, we propose an integrable method to detect biofluorescent spectrums with designed liquid crystal tunable filter (LCTF), in order to identify typical biological samples such as cells and bacteria. Hela cells labeled with red and green fluorescent proteins and Pseudomonas with fluorescence wavelengths of 610 nm, 509 nm and 450 nm, respectively, are inspected. High-resolution (6 μm) biofluorescent results have been achieved, together with clear images of the Hela cell clusters and the Pseudomonas bacteria colonies. Biofluorescence signals can be detected at a high transmittance (above 80%), and the response time of the device can reach 20 ms or below. The proposed method has the potential to be integrated into a microfluidic system to detect and identify the biofluorescent signals as a high throughput, low-cost option, for both high resolution and large field observation applications.

High Light Efficiency Spectral Polarization Imaging Method Based on Mach–Zehnder Structured Liquid Crystal Tunable Filters and Variable Retarders

“…An optical filtered SPI is a common alternative to other SPI techniques owing to the simple imaging principle; in other words, it is used to place an external filter in front of a monochromatic imager and acquire images at each spectral band sequentially. In addition to using a filter wheel [18] or color filter array [19], acousto-optic tunable filters (AOTF) [20] and LCTF [21] are frequently used because they can freely switch different spectral band at high speed (ms/or faster) and contain no mechanical moving components. However, the spatial resolution and the optical throughput of an optical filter SPI system are essentially limited by its filtering performance such as bandwidth and energy transmittance of light, respectively.…”