The Hazards of Microplastics
Plastic products are widely used in modern society due to their convenience and durability. However, excessive reliance on plastics has led to a sharp increase in plastic waste, contributing to the global environmental challenge of white pollution. Among the various forms of white pollution, microplastic pollution is particularly concerning. Microplastics refer to plastic particles smaller than 5 mm in diameter, which are difficult to detect due to their tiny size, but pose severe environmental hazards.
Microplastics have spread to every corner of the Earth, including glaciers, oceans, soil, and living organisms, making them nearly ubiquitous. Not only can microplastics adsorb toxic and harmful substances, becoming "sources of pollution" in marine environments, but they are also easily ingested by marine organisms, leading to digestive tract blockages and nutrient absorption issues. Moreover, microplastics can bioaccumulate through the food chain, eventually accumulating in the human body, potentially causing damage to the digestive, reproductive, and even nervous systems 1. (Figure 1)
Current Situation and Challenges
Although the academic community widely acknowledges the pollution and hazards posed by microplastics, the issue remains largely overlooked in public life and national policy frameworks. Taking China as an example, current wastewater treatment regulations lack specific requirements for addressing microplastics 2. Our research has identified two main issues that contribute to this situation:
First, public awareness of microplastics is relatively low. Unlike PM2.5, microplastics do not cause visible phenomenon like smog, and are difficult to detect using simple methods. The current detection of microplastics still relies on specialized laboratory equipment, such as spectrometers and chromatographs, which hinders the public’s direct understanding of the pollution and delays policy updates. Is there a way to enable the public to easily detect microplastics?
Second, the existing technologies face economic challenges. Conversations with wastewater treatment industry experts revealed that current methods for addressing microplastics require highly specialized equipment and the use of targeted water purification agents, leading to significant operational costs for wastewater treatment plants. Is there a way to enhance the value of plastic waste, making its treatment more economical and sustainable?
To address these issues, the UESTC-China team has proposed a solution for the identification and upcycling of microplastics—SPETEX.
Our Solutions
SPETEX, a specialised, precise, and efficient way to exterminate PET. Our work mainly consists of the following three parts:
1. Identification
In terms of detection, we have designed a biosensor based on microplastic anchoring peptides. The anchoring peptides are a class of peptides that can specifically bind to plastics. By modifying them onto the surface of Au colloid, we have developed a colorimetric reagent for detecting plastics. When plastics were mixed with the reagent, a visible color change occurred. By measuring the RGB values and UV spectrum of the reaction, we can quantitatively analyze the plastic concentration.
This detection method is simple to operate, highly sensitive, and provides accurate results. The general public can easily use it in daily life, allowing them to directly perceive the severity of the current microplastic pollution issue. This, in turn, raises social awareness and ultimately prompts updates to national laws and regulations.
2. One-Pot Synthesis
Polyethylene terephthalate (PET) plastic has been widely used due to its convenience and durability; however, its resistance to natural degradation has led to serious environmental issues. Biodegradation offers a potential solution for converting waste plastics into valuable resources under low-energy conditions. Based on this, we have developed a "one-pot" system that combines surface display technology and multi-enzyme systems to upgrade PET microplastics into high-value-added vanillin. Harnessing the power of synthetic biology, we aim to overcome the technical and cost barriers in PET plastic treatment, laying a significant foundation for the sustainable degradation and valorization of solid waste, thereby contributing to the planet’s sustainable development.
3. Project Optimization
The work on the two main lines of the project has been further optimized from multiple perspectives.
By incorporating advanced modeling techniques, such as machine learning and directed evolution, this project notably enhanced the detection accuracy of anchoring peptides and improved the efficiency of PET plastic degradation processes. Additionally, we applied gene editing technology to knock out the yahK gene in Escherichia coli, inhibiting vanillin degradation and thereby boosting its production.
Ultimately, this project realized an integrated solution that encompasses detection, degradation and real-time data visualization through team hardware, thereby offering a comprehensive and sustainable framework for the reutilization of plastic waste.
