Phage-based dual-mode sensor using ECL and EIS for sensitive detection of Pseudomonas Aeruginosa

Pseudomonas aeruginosa is a major pathogen responsible for severe infections, particularly in immunocompromised patients and those with chronic conditions. Its increasing resistance to antibiotics underscores the urgent need for effective detection systems. This study introduces a novel biosensor based on bacteriophage (M-PAP1) in combination with MWCNT-COOH modified SPE and its application for the sensitive identification of Pseudomonas aeruginosa. The phage provides high specificity and strong target binding, while the combined ECL and EIS modes offer complementary signal outputs, enhancing analytical reliability and reducing false responses. The ECL sensor achieved LoD of 0.755 CFU ml^-1and demonstrated a broad linear working range of 2.28 to 10¹⁰ CFU ml^-1 (R²: 0.9981). In artificial urine samples, the sensor demonstrated a recovery rate of 92% to 97%, indicating its effectiveness in real biological matrices. The dual functionality for both ECL and EIS measurements highlights the system's versatility and potential for real-time clinical applications. The system also exhibited exceptional selectivity and minimal interference from non-specific bacteria such as Escherichia coli and Pseudomonas putida and Pseudomonas fluorescens. Overall, the dual-mode strategy significantly strengthens diagnostic accuracy by enabling cross-validated detection signals, offering a robust platform for rapid monitoring of P. aeruginosa in the context of rising antimicrobial resistance.