<p>➀ A joint team from the University of Stuttgart and the University of Melbourne developed a cost-effective method using an "optical sieve" to detect nanoplastics (0.2–1 µm) in environmental samples, requiring only a standard optical microscope; </p><p>➁ The technique utilizes semiconductor substrates etched with "Mie voids" that produce color changes when particles are trapped, enabling rapid size and quantity analysis without complex equipment; </p><p>➂ The method has potential applications in on-site environmental monitoring and health research, with plans to adapt it for irregular particles and real-world water samples.</p>