Abstract：
Detecting unexploded landmines is critical due to the environmental pollution and potential humanitarian risks caused by buried landmines. Therefore, this study focused on developing a biosensor system capable of detecting explosives safely and efficiently. A novel transcription factor-based Escherichia coli biosensor was designed to detect 1,3-dinitrobenzene (1,3-DNB). The MexT transcription factor from Pseudomonas putida (P. putida) was identified as the fundamental sensing element in this biosensor. The study found that MexT positively regulated the transcription of PP_2827 by binding to the bidirectional promoter region between them, and significantly enhanced the expression of downstream genes under the condition of 1,3-DNB. The MexT-based biosensor for 1,3-DNB was developed by adopting different combinations of the mexT gene and promoters. The optimized biosensor demonstrated adequate sensitivity for detecting 0.1 μg/mL of 1,3-DNB in a liquid solution with satisfactory specificity and long-term stability. Subsequently, the MexT-based biosensor was integrated into a detection device to simulate the in-field exploration of explosives. The system exhibited a detection sensitivity of 0.5 mg/kg for 1,3-DNB in the sand, and realized the detection of on-site and large-scale area and the location of buried 1,3-DNB under the soil. The study provided a novel transcription factor-based bacterial biosensor and a complete system (China Earth Eye, CEE) for sensitive detection of 1,3-DNB. The good performance of this biosensor system can facilitate the development of accurate, on-site, and high-efficient exploration of explosives in real extensive minefields. Moreover, this 1,3-DNB biosensor can be complementary to the 2,4-DNT biosensor reported before, demonstrating its potential applications in military situations.
摘要：
由于埋藏的地雷造成的环境污染和潜在的人道主义风险，探测未爆炸的地雷至关重要。因此,这项研究的重点是开发一种能够安全有效地检测爆炸物的生物传感器系统。设计了一种新型的基于转录因子的大肠杆菌生物传感器，用于检测1,3-二硝基苯（1,3-DNB）。来自恶臭假单胞菌的MexT转录因子（P。putida）被确定为该生物传感器中的基本传感元件。研究发现,MexT通过与PP_2827之间的双向启动子区结合,并在1,3-DNB条件下显著增强下游基因的表达。通过采用mexT基因和启动子的不同组合开发了基于MexT的1,3-DNB生物传感器。优化的生物传感器显示出足够的灵敏度，可检测液体溶液中0.1μg/mL的1,3-DNB，具有令人满意的特异性和长期稳定性。随后，将基于MexT的生物传感器集成到检测装置中，以模拟爆炸物的现场勘探。该系统对沙子中的1,3-DNB的检测灵敏度为0.5mg/kg，并实现了现场和大规模区域的检测以及土壤下埋藏的1,3-DNB的位置。这项研究提供了一种新型的基于转录因子的细菌生物传感器和一个完整的系统(中国地球眼，CEE)用于1,3-DNB的灵敏检测。这种生物传感器系统的良好性能可以促进准确、现场,以及在真正的广泛雷区中对炸药的高效勘探。此外，这种1,3-DNB生物传感器可以与之前报道的2,4-DNT生物传感器互补，展示其在军事场合的潜在应用。
