Label-free, real-time, and quantitative assessment of PBAT biodegradation using a microfluidic system

In this study, we present the Microfluidic Tracking and Real-time Analysis of Biodegradable Microparticles (μ-TraceBio) platform, a fluorescence-based on-chip system for rapid, real-time, and quantitative assessment of biodegradable plastic degradation. Uniform poly(butylene adipate-co-terephthalate) (PBAT) microparticles with an average diameter of 245.3 μm (CV = 0.41 %) were fabricated using a microfluidic device, enabling highly reproducible degradation analysis. Only 270 μL of PBAT solution generated 376 monodisperse microparticles, each confined in microwell arrays for independent cutinase-mediated degradation under controlled conditions. Degradation was monitored in real time by tracking the reduction of PBAT's intrinsic fluorescence. The fluorescence-based method yielded 78.73 % degradation, in excellent agreement with gravimetric analysis (78.71 %, Δ = 0.03 %), validating the platform's quantitative accuracy. Compared with conventional film assays (16.67 % degradation), μ-TraceBio enabled over fourfold higher degradation extent, faster reactions, and improved reproducibility by eliminating manual handling. This robust, scalable system provides a standardized framework for evaluating bioplastic degradability and can be extended to other polymers, enzyme variant screening, and microbial biodegradation studies.