Fig. 3: A smartphone-based pH-indicator gas sensor array monitors brightness changes to detect E. coli at 10¹ CFU/mL and P. aeruginosa/S. aureus at 10² CFU/mL in real time.
From: Artificially intelligent nasal perception for rapid sepsis diagnostics
a The figure demonstrates a smartphone-based gas sensor array system for real-time detection and quantification of bacterial growth. The system features a smartphone cradle, a dedicated power supply, an on/off switch for LED illumination control, an integrated gas sensor array plate, and a built-in ventilation module to ensure proper airflow. b The gas emissions from three bacterial species (E. coli, P. aeruginosa, and S. aureus) cause a time-dependent decrease in brightness across BPB-PIL, TET-PIL, and Cu-PAN pH indicator systems, with 10¹ CFU/mL (Orange), 10² CFU/mL (blue), and 103 CFU/mL (pink). c A real-time PCR evaluates detection limits of 10¹ CFU/mL for E. coli (red), 10² CFU/mL for P. aeruginosa (green), and 10² CFU/mL for S. aureus (navy blue).
