Passive Amine Sensor Using NQS-PDMS Composite

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Solution Overview

Problem

Current methods for detecting volatile amines in gases, especially in real atmospheres, lack sensitivity and accuracy, and existing passive sensors are unable to detect low concentrations effectively, requiring external energy sources or complex pre-treatments.

Innovation Solution

A passive colorimetric sensor is developed by embedding 1,2-naphthoquinone-4-sulfonate (NQS) in a polydimethylsiloxane (PDMS) matrix, which acts as a derivatization reagent, allowing for in situ detection and quantification of amines without external energy, with a limit of detection as low as 3 mg/m³, enabling real-time monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If passive sampling technique is used for amine detection, then energy cost is reduced to zero and simplicity is improved, but detection sensitivity and limit of detection are insufficient for low concentration amines

Engineering Contradiction:
ImprovesimplicityVSAvoidlimit of detection
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent changes the chemical parameters of the sensing material by using a novel composite of 1,2-naphthoquinone-4-sulfonate (NQS) embedded in polydimethylsiloxane (PDMS) matrix. This chemical composition change enables the sensor to achieve low detection limits (3.2 mg/m³) while maintaining passive operation, resolving the contradiction between simplicity and detection sensitivity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite material system where NQS (derivatization agent) is embedded in a PDMS matrix. This composite structure combines the high reactivity of NQS with the stability and porosity of PDMS, enabling both passive operation and high detection sensitivity for trace amine analysis.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If derivatisation agents are used to convert amines into detectable products, then detection sensitivity is improved, but device complexity and need for pre-treatment increase

Engineering Contradiction:
Improvedetection sensitivityVSAvoidpre-treatment requirement
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the derivatization function and detection function into a single integrated passive sensor device. The NQS derivatization agent is embedded directly in the PDMS matrix, allowing amines to be derivatized and detected in one step without separate pre-treatment equipment or complex procedures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The passive sensor performs self-derivatization of amines through the NQS embedded in the PDMS matrix without requiring external energy sources, pumps, or complex pre-treatment equipment. The sensor automatically converts and detects amines in situ, eliminating the need for complex external derivatization equipment.

Inventive Principle:
Principle #25Self-service

3Productivity

If active sampling technique is used for rapid amine detection, then detection time is reduced, but energy consumption and equipment requirements increase

Engineering Contradiction:
Improvedetection speedVSAvoidenergy cost
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The sensor performs self-sampling and self-detection without requiring external energy sources, pumps, or active sampling equipment. The passive diffusion of amines into the PDMS matrix followed by in-situ derivatization with NQS enables rapid detection without energy consumption, resolving the contradiction between detection speed and energy use.

Inventive Principle:
Principle #25Self-service

4Use of energy by stationary object

If existing passive sensors are used for amine detection, then energy cost is reduced, but accuracy and reproducibility are insufficient

Engineering Contradiction:
Improveenergy costVSAvoidaccuracy
Core Design Contradiction:
Use of energy by stationary objectVSMeasurement precision

Solution Approach 1:

The patent changes the chemical and physical parameters of the sensing material by using NQS embedded in PDMS. This composition enables the sensor to maintain passive operation (zero energy cost) while achieving high accuracy and reproducibility through the specific chemical reactivity of NQS with amines and the stable matrix structure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The NQS-PDMS composite material combines the high chemical reactivity of NQS for amine derivatization with the physical stability and porosity of PDMS, enabling passive sensors to achieve high accuracy and reproducibility without requiring external energy sources or complex equipment.

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 sensor provides improved sensitivity and accuracy for detecting amines at low concentrations, is environmentally stable, and does not require pre-treatment or external instruments, enabling reliable detection and quantification in real atmospheres with enhanced reproducibility and stability.

Implementation Method 1

Amines have properties such as high volatility and polarity, they are chemically unstable and, in addition, do not have ultraviolet absorbance or fluorescence emission. In order to provide a solution to the problem of the detection thereof, there are various methods that propose converting the amines into a more stable product, which can be detected, by way of a derivatisation agent.

Methodology Applied
Scientific EffectColorimetric reaction: Chemical Bonding

Implementation Method 2

A passive colorimetric sensor is developed by embedding 1,2-naphthoquinone-4-sulfonate (NQS) in a polydimethylsiloxane (PDMS) matrix

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP3001184B1Passive device for the detection and/or determination in situ of amines in gases
Publication Date: 2020.03.25 UNIV DE VALENCIA
  • EP3001184B1 patent drawingFigure 1a~1b
  • EP3001184B1 patent drawingFigure 2a~2be
  • EP3001184B1 patent drawingFigure 3a~3b

AI summary

A sensor for the detection and/or determination in situ of amines in air, such as atmospheric air, is obtained by means of a direct, easy and reproducible synthesis consisting in soaking the derivatisation agent sodium 1,3-naphthoquinone-4-sulfonate (NQS) in polydimethylsiloxane (PDMS). It has been shown that the device can detect amine concentrations of 3 mg/m3 in 5 hours. Both the device and its response to the presence of gamines remain stable over time. In addition, no external source is required for detection (i.e. it is a passive sensor that allows gamines to be detected by means of visual inspection), requiring zero energy cost and having no toxicity, since both the NQS and the PDMS are non toxic.