Ultrasensitive Electrochemical Biosensors Based on Allosteric Transcription Factors (aTFs) for Pb²⁺ Detection

Exposure to Pb²⁺ in the environment, especially in water, poses a significant threat to human health and urgently necessitates the development of highly sensitive Pb²⁺ detection methods. In this study, we have integrated the high sensitivity of electrochemical techniques with allosteric transcription factors (aTFs) to develop an innovative electrochemical biosensing platform. This biosensors leverage the specific binding and dissociation of DNA to the aTFs (PbrR) on electrode surfaces to detect Pb²⁺. Under the optimal conditions, the platform has a broad linear detection range from 1 pM to 10 nM and an exceptionally low detection threshold of 1 pM, coupled with excellent selectivity for Pb²⁺. Notably, the biosensor demonstrates regenerative capabilities, enabling up to five effective Pb²⁺ measurements. After one week of storage at 4 °C, effective lead ion detection was still possible, demonstrating the biosensor's excellent stability, this can effectively save the cost of detection. The biosensor also achieves a recovery rate of 93.3% to 106.6% in real water samples. The biosensor shows its potential as a robust tool for the ultrasensitive detection of Pb²⁺ in environmental monitoring. Moreover, this research provides new insights into the future applications of aTFs in electrochemical sensing.