Searching and identifying microplastics in marine environment by digital holography

Microplastics (MP) have gained enormous attention in the last years as they are among the major contaminants of soil and oceans, able to insert themselves in the food chain and cause severe damage to plants life, fauna and human health. Many techniques have been proposed to analyze the abundance, concentration and presence of such material in water, but data are still incomplete. Here, we propose digital holography (DH) as a non-invasive technique to search for and reconstruct the shape of different types of MP. We prove DH is a suitable tool for identifying MP also in the presence of other objects in water, such as diatoms.