Towards sustainable diagnostics: assessing biodegradable lateral flow cassettes in real world conditions in Africa

Abstract

Introduction The widespread use of Lateral Flow Assays (LFAs) has significantly improved diagnostic accessibility in low- and middle-income regions, yet their reliance on single-use plastic cassettes poses urgent environmental concerns as conventional plastics persist for centuries, degrading only into harmful microplastics. Methods This study evaluated the biodegradability of certified plant-based diagnostic cassettes developed by Okos Diagnostics under field conditions in Nigeria using a 4-month controlled burial study across three soil types: sandy, clayey, and loamy. The biodegradable cassettes, made from certified plant-based polymers, were monitored using precision weight analysis and qualitative degradation assessments, compared against conventional plastic controls. Results Results demonstrated statistically significant degradation in biodegradable cassettes with weight increases of 7.44% ± 0.12% (sandy), 7.02% ± 0.08% (clayey), and 11.36% ± 0.16% (loamy soil), which showed the highest degradation rate. Observed initial weight increases primarily reflect moisture uptake and microbial biofilm formation on cassette surfaces rather than net polymer mass gain; these early-stage changes precede fragmentation and mineralization during biodegradation. ANOVA analysis revealed significant differences between soil types (F=15.7, p < 0.001) and materials (F=89.3, p < 0.0001), while plastic controls showed negligible change (1.36% ± 0.04%). Posthoc Tukey analysis showed that degradation in loamy soil was significantly higher than in sandy and clayey soils ( p < 0.05). Discussion The study validates biodegradable cassettes as eco-friendly alternatives capable of reducing diagnostic waste in resource-limited settings and provides baseline biodegradation data for tropical environments to inform global standards on sustainable diagnostic materials.