Utilizing Parasitic Capacitance of Single-Droplet Electricity Generator For Specific Bacterial Detection

Single-droplet electricity generator (SDEG) has superior potential over other solid-liquid triboelectric nanogenerators (TENGs) for energy harvesting. However, its shunting effect of parasitic capacitance is adverse and unavoidable, resulting in the reduction of the SDEG voltage. In addition, TENG-based bacterial biosensors are still facing issues of incompetence in resolution, precision, and specificity. Therefore, a novel SDEG-based bacterial biosensor is developed by making use of parasitic capacitance. By taking the advantages of aptamer and parasitic capacitance, the Pseudomonas aeruginosa (P. aeruginosa) can be specifically and precisely detected via signal change from a single droplet without energy accumulation. This study proves that the SDEG-based bacterial biosensor exhibits an excellent performance for P. aeruginosa detection in low limit of detection (4.5x10(3) CFU mL(-1)) with high selectivity. Meanwhile, the established mathematical model yields consistent results to the experimental ones, which serves as a solid basis for quantifying bacterial concentration. This work contributes to TENG-based bacterial biosensor, and opens up a new way for the diversified application of SDEG.