Vertical Nanogap Electrode Aggregation for Nanoplastic Raman Detection
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Solution Overview
Problem
Existing methods struggle to detect nanoplastics in aquatic ecosystems due to their ultra-low concentration and nano-scale size, which exceeds the diffraction limit of Raman spectroscopic devices, and there is a lack of effective methods for collecting and concentrating nanoplastics to enable detection.
Innovation Solution
A method using a vertical nanogap electrode and Raman spectroscopy is employed to collect and concentrate nanoplastics into aggregates of micrometer size by applying an alternating voltage, leveraging AC-electroosmosis and dielectrophoresis to overcome diffusion and diffraction limits, enabling detection through Raman spectroscopy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Raman spectroscopy is used to detect nanoplastics, then qualitative analysis capability is improved, but detection is impossible due to diffraction limit for particles smaller than 20 μm
Solution Approach 1:
The patent applies preliminary action by collecting and concentrating nanoplastics into aggregates before Raman spectroscopy detection. The vertical nanogap electrode pre-concentrates nanoplastics from dilute aquatic environments into micrometer-sized aggregates, making them detectable by Raman spectroscopy which otherwise cannot detect individual nanoplastic particles due to the diffraction limit
Solution Approach 2:
The patent merges nanoplastics into larger aggregates through concentration processes. By combining multiple nanoplastic particles into micrometer-sized aggregates using the vertical nanogap electrode, the detection target transitions from sub-diffraction individual particles to super-diffraction aggregate structures that can be detected by conventional Raman spectroscopy
2Measurement precision
If conventional analysis devices are used to detect nanoplastics, then detection capability for individual particles is improved, but detection is impossible due to ultra-low concentration (0.02 mg/L) and diffusion limit
Solution Approach 1:
The vertical nanogap electrode performs preliminary concentration of nanoplastics from ultra-low concentration aquatic environments. By pre-concentrating nanoplastics into detectable aggregates before analysis, the system overcomes the diffusion limit and ultra-low concentration challenge that prevent conventional devices from detecting nanoplastics in natural water bodies
Solution Approach 2:
The vertical nanogap electrode acts as an intermediary between the dilute nanoplastic environment and the detection system. It mediates the concentration process by collecting scattered nanoplastics and forming them into aggregates, bridging the gap between ultra-low concentration particles and the detection threshold of analytical instruments
3Quantity of substance
If nanoplastics are collected for analysis, then sample availability is improved, but detection remains difficult due to nanoscale size and lack of concentration into detectable forms
Solution Approach 1:
The system performs preliminary concentration by collecting nanoplastics and forming them into micrometer-sized aggregates before detection. This pre-processing step transforms collected nanoplastics from undetectable nanoscale particles into detectable aggregate structures, solving the problem where collection alone is insufficient for detection
Solution Approach 2:
The patent changes the size parameter of nanoplastics from nanoscale to micrometer scale through aggregation. By transforming the physical dimension parameter of the target particles, the system makes them detectable by conventional optical methods while preserving their chemical identity for Raman spectroscopy analysis
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
This approach allows for the detection of nanoplastics at concentrations as low as 0.01 mg/L by forming aggregates larger than the laser wavelength, overcoming previous limitations and enhancing detection sensitivity.
Implementation Method 1
applying an alternating voltage, leveraging AC-electroosmosis and dielectrophoresis to overcome diffusion and diffraction limits
Implementation Method 2
applying an alternating voltage, leveraging AC-electroosmosis and dielectrophoresis to overcome diffusion and diffraction limits
Implementation Method 3
performing Raman spectroscopy on the nanoplastic aggregate concentrated in the collector of the vertical nanogap electrode to detect the nanoplastic constituting the nanoplastic aggregate
Data Source
AI summary
A method for detecting a nanoplastic using a vertical nanogap electrode and a Raman spectroscopic device, includes, in a state where a vertical nanogap electrode is provided in aquatic environment in which a nanoplastic exists, forming a nanoplastic aggregate having a size of 1 μm or more by applying an alternating voltage of a specific frequency to the vertical nanogap electrode, and collecting and concentrating the nanoplastic in a collector of the vertical nanogap electrode, and performing Raman spectroscopy on the nanoplastic aggregate concentrated in the collector of the vertical nanogap electrode to detect the nanoplastic constituting the nanoplastic aggregate.