UV LED Time-Resolved Fluoroimmunoassay Detection
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Solution Overview
Problem
Current time-resolved fluoroimmunoassay detection systems face challenges in sensitivity and signal-to-noise ratio due to the use of excitation sources like Xenon flash lamps, which have long afterglow and high costs, and UV LEDs, which have low power output, making them unsuitable for detecting low concentrations of target substances effectively.
Innovation Solution
A system utilizing a light emitting diode (LED) with peak intensity emission below 355 nm, delivering pulsed excitation light with a duration of at least 50 μs, optimized to achieve sufficient total pulse energy and excitation efficiency, paired with a control unit for gated detection, enhances signal-to-noise ratios and compatibility with lanthanide-based fluorophores like Europium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If Xenon flash lamps are used as excitation sources, then high power output and spectral versatility are achieved, but long afterglow reduces signal-to-noise ratio and costs increase
Solution Approach 1:
The patent replaces expensive Xenon flash lamps with UV LEDs that have no afterglow. While individual UV LEDs have lower peak power, their long operational life and absence of afterglow make them a sustainable replacement that improves signal-to-noise ratio without the cost and performance penalties of flash lamps.
Solution Approach 2:
The patent changes the temporal parameters of excitation by using pulsed UV LED excitation with pulse durations of 1-10 microseconds. This parameter change allows sufficient excitation energy delivery while eliminating the long afterglow problem of flash lamps, thereby improving signal-to-noise ratio.
2Power
If UV LEDs are used as excitation sources, then low cost and no afterglow are achieved, but low power output reduces excitation efficiency
Solution Approach 1:
The patent employs periodic pulsed excitation with UV LEDs at frequencies and pulse durations (1-10 μs) optimized for time-resolved detection. This periodic action accumulates sufficient excitation energy over multiple pulses while maintaining the cost advantage of LEDs and eliminating afterglow interference.
Solution Approach 2:
The patent optimizes UV LED operational parameters including pulse duration (1-10 μs), repetition frequency, and drive current to achieve sufficient total excitation energy. These parameter changes compensate for lower peak power while maintaining cost effectiveness and eliminating afterglow.
3Use of energy by moving object
If pulsed excitation with duration of at least 50 μs is used, then sufficient total pulse energy is achieved, but pulse duration must be balanced against fluorescence lifetime
Solution Approach 1:
The patent optimizes excitation pulse duration to 1-10 microseconds, which is carefully balanced to deliver sufficient total energy for effective excitation while remaining shorter than the microsecond-to-millisecond fluorescence lifetime of lanthanide chelates. This parameter optimization ensures high signal-to-noise ratio through time-gated detection.
Solution Approach 2:
The patent employs dynamic control of pulse parameters including duration, frequency, and intensity to adapt excitation conditions to the specific fluorescence lifetime of the lanthanide chelate being detected. This dynamic adjustment optimizes energy delivery while maintaining temporal resolution for time-gated detection.
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 LED-based system achieves improved signal-to-noise ratios and efficient excitation in time-resolved fluoroimmunoassay detection, overcoming the limitations of traditional systems by balancing pulse energy and efficiency, and is compatible with automated analysis apparatus and standardized lab-ware.
Implementation Method 1
a light source adapted to emit pulsed excitation light; wherein the light source is a light emitting diode with a peak intensity emission at a wave length below 355 nm
Implementation Method 2
detecting fluorescence radiation emitted from the sample in response to the pulse of excitation light; Many fluorophores with long fluorescence lifetime belong to the group of lanthanides. Europium is a lanthanide ion, which has been used as a marker in time-resolved fluorescence instruments due to its large Stokes shift and long fluorescence lifetime in the microsecond-(μs) to millisecond-(ms) regime
Implementation Method 3
an optical filter device configured for the separation of excitation light and detection light
Implementation Method 4
Time-gated fluorescence detection delayed by microseconds with respect to the short excitation pulse exhibits improved signal-to-noise ratio (SNR) comparing to steady measurements as it reduces background of typical fluorescence lifetimes that are in range of nanoseconds
Data Source
AI summary
A system for time-resolved fluoroimmunoassay detection is disclosed. The system comprises a receptacle with a sample volume adapted for receiving a sample therein; a light source adapted to emit pulsed excitation light illumination optics adapted to collect the pulsed excitation light from the light source and to deliver the pulsed excitation light to the sample volume in the receptacle; a detection device adapted for gated detection of fluorescence radiation at least in a detection spectral range; detection optics adapted to collect fluorescence radiation from the receptacle at least in the detection spectral range and deliver the fluorescence radiation to the detection device; and an optical filter device configured for the separation of excitation light and detection light. A method for time-resolved fluoroimmunoassay detection is also provided.