Self-powered biosensing system driven by triboelectric nanogenerator for specific detection of Gram-positive bacteria

Gram-positive bacterial concentration, such as Staphylococcus aureus (S. aureus), is a crucial criterion for evaluating water quality and influencing human health, developing effective and specific detection of Gram-positive bacteria is important for prevention of their threats. In our proof-of-concept work, a self-powered biosensing system based on the vertical contact-separation triboelectric nanogenerator (TENG) was developed to specifically detect Gram-positive bacteria in solution. In the biosensing system, vancomycin was utilized to identify and capture Gram-positive bacterial cells via specific vancomycin-bacteria wall interactions, guanidine functionalized multi-walled carbon nanotubes (CNT-Arg) was adopted as signal amplification material due to its high electrical conductivity, and TENG was adopted as a stable voltage signal source. Thus, the self-powered biosensing system could specifically detect the Gram-positive bacteria in solution by determining the measured voltage variation of biosensor. It was proven that the self-powered biosensing system was applied to detect S. aureus (employed as a model) with a linear relationship, low limit of detection (2 × 103 CFU mL−1) and high selectivity. Moreover, a warning program of Labview was written in this work, and the warning program could convert the voltage signal into visual signal for convenient observation. This work provides a design concept for self-powered biosensing system with TENG, and by replacing the molecular probes, the system can facilitate the application of TENG in many relevant fields, such as environmental pollution, iatrogenic diseases and microbiological corrosion.