Description
The issue of microplastics (MPs) pollution is becoming increasingly significant for the environment and health due to the uncontrolled release of plastic waste. It is also a health concern, particularly when considering their release in pharmaceutical liquid products. This serious contamination, which has become a concern since the last few years, demands the development of new methodologies for the sensing of MPs, particularly when the latter are dispersed in water. Opto-microfluidics is a promising solution for the effective and fast detection of MPs. This is due to its inherent capability of handling and dealing with liquid samples, while ensuring high-throughput analysis. In this work, we used a droplet-based opto-microfluidic device integrated on a lithium niobate substrate in order to analyse water droplets containing plastic microspheres with a diameter lower than one micrometre. Their detection is achieved by combining both the multispectral imaging and the analysis of the transmitted light intensity through the droplets, distinguishing between liquid solutions from those with suspensions of MP particles in concentrations up to few mg/g. The focus of this study is the interaction between light droplets, with a particular emphasis on assessing the impact of various factors on sensing. These factors include microplastics size and concentration and identification and investigating the relative detection limits.