Fluorescence Detection Using Cholesteric Liquid Crystal Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluorescence detection devices suffer from low detection sensitivity due to the presence of dichroic mirrors and inefficiencies in removing excitation light, particularly when holding liquid samples on substrates.
Innovation Solution
A fluorescence detection device utilizing a cholesteric liquid crystal layer that transmits fluorescence while reflecting excitation light, employing a light source that emits circularly polarized light, and a sensor to detect the transmitted fluorescence, thereby reducing noise from excitation light and enhancing detection sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a dichroic mirror is used to separate excitation light from fluorescence, then the detection device can filter excitation light, but the detection sensitivity is reduced due to light loss and interference
Solution Approach 1:
The patent extracts the harmful excitation light from the detection path by using a cholesteric liquid crystal layer that selectively reflects excitation light while transmitting fluorescence. This separates the harmful component (excitation light) from the useful signal (fluorescence) without requiring complex dichroic mirror systems, thereby improving detection sensitivity.
Solution Approach 2:
The patent changes the optical parameters of the cholesteric liquid crystal layer to achieve wavelength-selective reflection. By controlling the helical pitch and chirality of the liquid crystal molecules, the system reflects excitation light at specific wavelengths while transmitting fluorescence at different wavelengths, resolving the contradiction between filtering effectiveness and signal preservation.
2Device complexity
If excitation light is not effectively removed, then the optical system remains simple, but detection sensitivity is compromised due to noise from reflected excitation light
Solution Approach 1:
The patent introduces a cholesteric liquid crystal layer as an intermediary component between the sample and the detector. This layer acts as a selective optical mediator that reflects excitation light back toward the light source while allowing fluorescence to pass through to the detector, achieving effective excitation light removal with minimal increase in system complexity.
3Ease of manufacture
If conventional substrates are used to hold liquid samples, then the device structure is simple, but excitation light removal is inefficient leading to reduced detection sensitivity
Solution Approach 1:
The patent employs a composite structure combining a conventional substrate with a cholesteric liquid crystal layer. This composite material approach maintains the structural simplicity and ease of manufacture of traditional substrates while adding the optical functionality of the liquid crystal layer to efficiently remove excitation light and enhance detection sensitivity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves improved detection sensitivity by selectively reflecting excitation light and minimizing its interference with fluorescence detection, resulting in enhanced accuracy and precision of fluorescence measurements.
Implementation Method 1
a cholesteric liquid crystal layer configured to transmit fluorescence emitted by the sample due to the excitation light and reflect the excitation light
Implementation Method 2
a light source configured to irradiate a sample with excitation light in a circularly polarized state
Implementation Method 3
a light source configured to irradiate a sample with excitation light in a circularly polarized state
Implementation Method 4
a sensor configured to detect the fluorescence transmitted through the cholesteric liquid crystal layer
Data Source
AI summary
According to an aspect, a fluorescence detection device includes: a light source configured to irradiate a sample with excitation light in a circularly polarized state; a sample holder configured to hold the sample; a cholesteric liquid crystal layer configured to transmit fluorescence emitted by the sample due to the excitation light and reflect the excitation light; and a sensor configured to detect the fluorescence transmitted through the cholesteric liquid crystal layer.