Real-Time Monitoring of Self-Healing Biocement Using Embedded Bioluminescent Microbes

Our study introduces a real-time, non-destructive strategy for monitoring self-healing in biocement by integrating genetically engineered bioluminescent microorganisms. Microcracking in concrete infrastructure imposes annual repair expenditures exceeding US$18 billion in the United States, underscoring the need for effective in-situ diagnostics. Although microbially induced calcium carbonate precipitation (MICP) offers an attractive self-healing mechanism, existing evaluation techniques are invasive, intermittent, and incapable of capturing healing kinetics. We engineered three bacterial strains— Sporosarcina pasteurii, Bacillus subtilis, and Pseudomonas aeruginosa—to constitutively express luciferase, enabling emission of quantifiable light signals proportional to metabolic activity during mineralisation. Laboratory experiments across diverse environmental conditions and encapsulation schemes revealed a robust correlation (R² = 0.92) between bioluminescence intensity and calcium carbonate precipitation rate, with microcracks as small as 10 µm reliably detected. Field-scale validation under simulated climatic cycles confirmed sustained signal integrity over 24 monitoring events during twelve months, while achieving crack-closure efficiencies between 75 % and 89 %. The proposed biosensing platform furnishes unprecedented insight into temporal healing dynamics, facilitating optimisation of microbial formulations, predictive maintenance scheduling, and deeper elucidation of microbe–mineral interactions in cementitious matrices. Its implementation could significantly extend service life and reduce lifecycle costs of critical infrastructure assets. Beyond concrete, the technology can be adapted to other structural materials where real-time, autonomous health monitoring is imperative.