Cross-disciplinary translation of paper-based sensors for bacterial detection

Rapid detection of pathogenic bacteria is needed for clinical diagnosis, food safety, and environmental monitoring. Culture, PCR, and ELISA remain reliable, but their use outside laboratories is limited by long turnaround times, instruments, trained personnel, and sample-processing requirements. Paper-based sensors address part of this gap because they are inexpensive, portable, disposable, and driven by capillary flow, while supporting colorimetric, fluorescent, electrochemical, chemiluminescent, and smartphone-based readouts. Recent work has combined paper-based devices with microfluidics, nanomaterials, molecular biology, materials chemistry, electronics, and data analysis. For coordination chemistry, the central question is how metal-ligand chemistry changes the performance of these devices. Metal complexes, metal nanoparticles, metal nanozymes, metal-organic frameworks, coordination polymers, and aggregation-induced emission materials can improve bacterial enrichment, probe immobilization, catalytic amplification, optical/electrochemical transduction, and interface stability. This review discusses paper-based bacterial sensors from this coordination-chemistry perspective, covering device construction, analytical methods, detection targets, artificial-intelligence-assisted readout, commercialization, and applications in environmental, food, and clinical samples. We also compare how coordination structures affect sensitivity, selectivity, matrix tolerance, cost, and translational potential. Finally, we discuss remaining barriers, including quantitative reliability, interference from complex samples, reagent storage, batch reproducibility, biofilm detection, standardization, and commercial implementation, and outline directions for practical coordination-material-enabled paper diagnostics.