Technical Note: Multi-Matrix Feasibility of Microplastic-Nanoplastic Optical Assay in Complex Liquid Systems (Infant Formula Example)

As part of ongoing validation across consumer matrices for EcoExposure microplastic-nanoplastic detection platform, we conducted a proof-of-concept study in reconstituted infant formula, one of the most optically challenging real-world liquids due to its high turbidity, emulsion, proteins, lipids, and light-scattering properties (see Figure). Optical differences between microplastic-spiked infant formula sample and control sample were seen. These findings extend the platform well beyond clear aqueous environments (water, urine, blood) into everyday consumer liquids such as milk, juice, beverages, and infant formula. Unlike traditional laboratory methods that require months-to-years of matrix-specific re-optimization, the EcoExposure workflow uses the same core protocol across liquids with the app automatically correcting for dilution factor. Experiments further demonstrate that water is the starting point, not the endpoint. This multi-matrix capability directly supports growing public health priorities, including the FDA’s recent Operation Stork Speed infant formula testing program and the broader need for scalable microplastics monitoring in food and beverages. Further validation across additional matrices (milk, juice, etc.) is underway.