Plant-Extract Metal Nanoparticle Synthesis Without Capping Agents

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Solution Overview

Problem

Existing methods for producing metal nanoparticles pose environmental and safety concerns due to the use of chemicals like AgNO3 and inefficient bioreactors, and often require additional capping agents for nanoparticle stabilization.

Innovation Solution

A method involving the use of plant extracts from kale and other plants like artichoke, red cabbage, oregano, and rosemary to reduce metal ions into nanoparticles, forming a protective bio-layer without additional capping agents, and incorporating a recycle loop to minimize waste and environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If AgNO3 is used as silver salt for nanoparticle production, then nanoparticle synthesis is achieved, but environmental pollution from nitrate leaching occurs

Engineering Contradiction:
Improvenanoparticle synthesisVSAvoidenvironmental pollution
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces harmful AgNO3 with beneficial plant extracts that contain natural reducing agents. The plant extracts convert the harmful nitrate leaching problem into a beneficial green synthesis process where plant antioxidants reduce metal ions to nanoparticles without producing harmful waste, thus converting a harmful chemical process into an environmentally friendly one.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the chemical parameters of the synthesis process by substituting inorganic AgNO3 with organic plant extract-based reducing agents. This parameter change transforms the reaction mechanism from chemical reduction using strong oxidizing agents to biological reduction using plant antioxidants, thereby eliminating nitrate pollution while maintaining nanoparticle synthesis efficiency.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If additional capping agents are used for nanoparticle stabilization, then nanoparticle stability is improved, but process complexity and cost increase

Engineering Contradiction:
Improvenanoparticle stabilityVSAvoidprocess complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality to plant extracts that simultaneously serve as reducing agents, capping agents, and stabilizing agents. The same plant extract that reduces metal ions to form nanoparticles also provides the protective bio-layer that stabilizes the nanoparticles, eliminating the need for separate capping agents and simplifying the overall process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of reduction and stabilization into a single step by using plant extracts that perform both roles. The plant extract components are combined to provide both reducing power for nanoparticle formation and capping functionality for stabilization, thereby reducing process complexity and the number of separate chemicals required.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If conventional bioreactors are used for biosynthesis, then nanoparticle production is achieved, but reaction efficiency is low requiring 6 hours at 37°C

Engineering Contradiction:
Improvenanoparticle productionVSAvoidreaction time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent changes the reaction parameters by using plant extracts with higher concentrations of active reducing agents compared to conventional bioreactors. This parameter change enables the reaction to proceed much faster at lower temperatures, reducing the reaction time from 6 hours at 37°C to just 15 minutes at room temperature while maintaining high nanoparticle production efficiency.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If single plant extracts are used for nanoparticle synthesis, then process simplicity is maintained, but antioxidant activity and reaction efficiency are insufficient

Engineering Contradiction:
Improvereaction efficiencyVSAvoidcomposition complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent uses composite plant extracts combining multiple plant sources (kale, oregano, artichoke, red cabbage, rosemary, sage, watercress) to create a synergistic mixture with enhanced antioxidant activity. This composite approach leverages the complementary properties of different plants to achieve superior reducing power and reaction efficiency that cannot be obtained from single plant extracts alone.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent merges multiple plant extracts into a unified composition that works synergistically. The combination of extracts from different plants combines their respective antioxidants and reducing agents, creating a more powerful and efficient system for nanoparticle synthesis while maintaining practical process simplicity.

Inventive Principle:
Principle #5Merging (Combining)

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 method produces metal nanoparticles with a lower environmental footprint, using less material and energy, and provides a protective bio-layer, reducing the need for additional stabilizing agents, while being more cost-effective and scalable.

Implementation Method 1

such that the dissolved metal ion is reduced to form the metal nanoparticle

Methodology Applied
Scientific EffectReduction: Reduction

Data Source

PatentEP4204144B1Method of producing a metal nanoparticle
Publication Date: 2026.03.18 METALCHEMY LTD
  • EP4204144B1 patent drawingFigure 1
  • EP4204144B1 patent drawingFigure 1A
  • EP4204144B1 patent drawingFigure 2~3

AI summary

Compositions comprising extracts of kale and a number of other plants in synergistic mixtures are disclosed. A method of forming a metal nanoparticle and a nanoparticle formed using the method are disclosed.