A self-powered microbiosensor system for specific bacteria detection based on triboelectric nanogenerator

Gram-negative bacteria (Gnb) such as sulfate-reducing bacteria (SRB), as the main culprits of microbiological induced corrosion (MIC) in marine environment, cause severe problems for marine construction. Thus, the rapid and sensitive detection of Gnb is vital for environmental monitoring and metal corrosion protection. Herein, we developed a microbiosensor system based on triboelectric nanogenerator (TENG), by which Gnb such as SRB in the solution can be detected instantly. In the system, concanavalin A (ConA)-modified indium tin oxide glass (ITO-ConA) captures Gnb by specific recognition between ConA and Gnb; ConA-functionalized carboxyl multi-walled carbon nanotubes with high-conductivity serve as signal amplification material; and TENG provides a stable power supply to the microbiosensor system. Variation of Gnb concentration leads to changes in the adsorption capacity of CNT-ConA, which further results in the variation of resistance. Thus, the microbiosensor system could effectively detect the bacteria concentration based on the monitoring of output voltage. In addition, by integrating alarm circuit with microbiosensor, the detection results can be can be directly indicated by light emitting diode. Desulforibrio sp. Huiquan2017 was chosen as typical SRB for validating the performance of the as-obtained self-powered microbiosensor. In the detection range of 3 × 103 to 3 × 107 CFU mL−1, the correlation between peak voltage and bacteria concentration exhibits linear relation. Meanwhile, the detection mechanisms were further elucidated by adopting molecular simulations. This work not only offers an effective strategy for detecting Gnb, but also provides useful insights into the development of portability, specificity, and stability of TENG-based sensor systems.