Zinc-Selective Fluorescent Probes for Ratiometric Imaging

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for detecting dynamic changes in labile zinc levels within live cells are hindered by challenges such as phototoxicity from high-energy lasers and the inability of existing ratiometric indicators to respond with a spectral shift upon analyte binding, limiting the effectiveness of fluorescence microscopy techniques like TPEM.

Innovation Solution

Development of zinc-responsive fluorescent probes with a donor-π-acceptor design that undergo bathochromic shifts upon zinc binding, allowing for emission-ratiometric imaging through compounds like chromis-2, which exhibit a red shift in both absorption and emission spectra, reducing excited-state proton transfer and enhancing imaging capabilities in biological samples.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-energy lasers are used in conventional fluorescence microscopy for detecting zinc levels, then detection sensitivity is improved, but phototoxicity to live cells increases

Engineering Contradiction:

Improvedetection sensitivityVSAvoidphototoxicity

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the excitation parameter from single-photon (conventional fluorescence) to two-photon excitation (TPEM). This parameter change allows using lower energy per photon while achieving the same detection sensitivity, thereby reducing phototoxicity to live cells during zinc level monitoring

Inventive Principle:

Principle #35Parameter changes

2Reliability

If existing ratiometric indicators are used for zinc detection, then zinc binding capability is achieved, but spectral shift response upon analyte binding is not obtained

Engineering Contradiction:

Improvezinc binding capabilityVSAvoidspectral shift response

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by designing the fluorophore with distinct functional regions: a donor unit and an acceptor unit separated by a π-conjugated bridge. This local differentiation enables the molecule to exhibit both zinc binding capability (through the acceptor unit) and spectral shift response (through the donor-acceptor interaction), resolving the contradiction between reliability and measurement precision

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If emission-ratiometric imaging is implemented in TPEM, then reduced phototoxicity and increased depth penetration are achieved, but existing probes cannot provide spectral shift response upon analyte binding

Engineering Contradiction:

ImprovephototoxicityVSAvoidspectral shift response

Core Design Contradiction:

Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent creates a composite molecular structure combining a donor fluorophore, a π-conjugated bridge, and an acceptor unit with zinc-binding capability. This composite design enables the probe to function as both a two-photon excitable fluorophore (for reduced phototoxicity and depth penetration) and a spectral shift-responsive zinc indicator, simultaneously achieving all required properties

Inventive Principle:

Principle #40Composite materials

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 zinc-responsive probes enable pH-independent ratiometric imaging, allowing for accurate monitoring of labile zinc fluctuations in live cells and tissues with reduced phototoxicity, improving the sensitivity and depth penetration of microscopy techniques like TPEM.

Implementation Method 1

undergo bathochromic shifts upon zinc binding, allowing for emission-ratiometric imaging through compounds like chromis-2, which exhibit a red shift in both absorption and emission spectra

Methodology Applied

Scientific EffectBathochromic shift:

Implementation Method 2

zinc-responsive fluorescent probes with a donor-π-acceptor design that undergo bathochromic shifts upon zinc binding

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Implementation Method 3

reducing excited-state proton transfer and enhancing imaging capabilities in biological samples

Methodology Applied

Scientific EffectExcited-state proton transfer:

Implementation Method 4

Two-photon excitation microscopy (TPEM) can be employed in detection and quantification methods because compared to conventional fluorescence microscopy, TPEM offers multiple advantages, including reduced photo toxicity

Methodology Applied

Scientific EffectTwo-photon excitation:

Data Source

PatentUS11604141B2Zinc-selective fluorescent probes for emission-ratiometric imaging

Publication Date: 2023.03.14 GEORGIA TECH RES CORP

AI summary

The compounds relate to zinc-sensitive fluorescent probes, compositions and methods utilizing the same. Such compounds provide an emission-ratiometric fluorescence response upon binding of an analyte. In some embodiments, compounds can be used for two-photon excitation microscopy or conventional fluorescence microscopy. The compounds described herein can also contain one or more functional groups to improve the emission-ratiometric fluorescence response.