With the aggravation of sulfide pollution, more and more attention has been paid to the detection of sulfide in the environment. However, the detection of low-concentration sulfide is still a technical bottleneck to be solved urgently. In this study, a synergistic effect strategy that combines the co-catalysis of nanoporous gold (np-Au) and recombinant microbial cell with the excellent electrical conductivity of reduced graphene oxide (rGO) was proposed for the sensitive detection of low-concentration sulfide. A rGO/np-Au composite was fabricated and then used as an immobilization support for the bio-recognition element of recombinant Escherichia coli (E. coli) over-expressed sulfide: quinone oxidoreductase (SQR). A microbial biosensor (E. coliSQR/rGO/np-Au/GCE) was successfully constructed for the sensitive detection of low-concentration sulfide. Due to the synergistic effect of rGO, np-Au, and E. coliSQR cells, the sensitivity of the proposed microbial biosensor towards sulfide reached 400.42 μA mM-1 cm-2 with a wide linear response ranging from 100 nM to 7 mM, as well as a low detection limit of 98.5 nM using amperometric i-t curve method. Furthermore, the microbial biosensor was successfully applied to the detection of sulfide in wastewater with strong anti-interference ability, high reproducibility, and strong stability. These results confirmed that the proposed microbial biosensor was ideal for the detection of low-concentration sulfide in a reliable, specific, and sensitive way.

中文翻译：

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基于rGO，np-Au和重组微生物细胞的协同效应，可灵敏地检测低浓度硫化物。

随着硫化物污染的加剧，环境中硫化物的检测越来越受到关注。但是，低浓度硫化物的检测仍然是亟待解决的技术瓶颈。在这项研究中，提出了一种协同效应策略，该策略将纳米多孔金（np-Au）和重组微生物细胞的共催化与还原性氧化石墨烯（rGO）的优异电导率相结合，用于低浓度硫化物的灵敏检测。制备了rGO / np-Au复合材料，然后将其用作重组表达的大肠杆菌（E. coli）过表达的硫化物：醌氧化还原酶（SQR）的生物识别元件的固定支持物。成功构建了一种用于低浓度硫化物灵敏检测的微生物生物传感器（E. coliSQR / rGO / np-Au / GCE）。由于rGO，np-Au和E. coliSQR细胞的协同作用，拟议的微生物传感器对硫化物的敏感性达到400.42μAmM-1 cm-2，线性响应范围从100 nM到7 mM，以及使用安培it曲线法的98.5 nM的低检测限。此外，该微生物传感器成功用于抗硫化能力强，重现性强，稳定性强的废水中硫化物的检测。这些结果证实了所提出的微生物生物传感器对于以可靠，特异性和灵敏的方式检测低浓度硫化物是理想的。42μAmM-1 cm-2，线性响应范围从100 nM到7 mM，使用安培it曲线法的低检测限为98.5 nM。此外，该微生物传感器成功用于抗硫化能力强，重现性强，稳定性强的废水中硫化物的检测。这些结果证实了所提出的微生物生物传感器对于以可靠，特异性和灵敏的方式检测低浓度硫化物是理想的。42μAmM-1 cm-2，线性响应范围从100 nM到7 mM，使用安培it曲线法的低检测限为98.5 nM。此外，该微生物传感器成功用于抗硫化能力强，重现性强，稳定性强的废水中硫化物的检测。这些结果证实了所提出的微生物生物传感器对于以可靠，特异性和灵敏的方式检测低浓度硫化物是理想的。