Water Research ( IF 12.8 ) Pub Date : 2021-04-17 , DOI: 10.1016/j.watres.2021.117164 Xiang Qi , Shuyi Wang , Yong Jiang , Panpan Liu , Qingcheng Li , Wen Hao , Jinbin Han , Yuexi Zhou , Xia Huang , Peng Liang
A major challenge for devising an electrochemically active biofilm (EAB)-based biosensor for real-time water quality early-warning is the formation of EAB that requires several days to weeks. Besides the onerous and time-consuming preparation process, the naturally formed EABs are intensively concerned as they can hardly deliver repeatable electrical signals even at identical experimental conditions. To address these concerns, this study employed sodium alginate as immobilization agent to encapsulate Shewanella oneidensis MR-1 and prepared EAB for devising a biosensor in a short period of less than 1 h. The artificial EAB were found capable of delivering highly consistent electrical signals with each other when fed with the same samples. Morphology and bioelectrochemical properties of the artificial EAB were investigated to provide interpretations for these findings. Different concentrations of bacteria and alginate in forming the EAB were investigated for their effects on the biosensor's sensitivity. Results suggested that lower concentration of bacteria would be beneficial until it increased to 0.06 (OD660). Concentration of sodium alginate affected the sensitivity as well and 1% was found an optimum amount to serve in the formation of EAB. A long-term operation of the biosensor with artificial EAB for 110 h was performed. Clear warning signals for incoming toxicants were observed over random signal fluctuations. All results suggested that the artificial EAB electrode would support a rapid devised and highly sensitivity biosensor.
中文翻译:
人工电化学活性生物膜可改善感测性能并快速设计水质预警生物传感器
设计用于实时水质预警的基于电化学活性生物膜(EAB)的生物传感器的主要挑战是需要几天到几周的EAB的形成。除了繁琐且费时的制备过程外,天然形成的EAB还受到关注,因为它们即使在相同的实验条件下也几乎无法传递可重复的电信号。为了解决这些问题,本研究采用海藻酸钠作为固定剂来包囊希瓦氏菌MR-1和EAB用于在不到1小时的短时间内设计生物传感器。发现人工EAB在喂入相同样品时能够相互传递高度一致的电信号。研究了人工EAB的形态和生物电化学特性,为这些发现提供了解释。研究了形成EAB时不同浓度的细菌和藻酸盐对生物传感器灵敏度的影响。结果表明,降低细菌浓度直到增加至0.06(OD 660)。海藻酸钠的浓度也影响灵敏度,发现1%的最佳量可用于EAB的形成。带有人工EAB的生物传感器进行了110 h的长期操作。在随机的信号波动范围内,观察到清晰的警告信号提示有毒物进入。所有结果表明,人造EAB电极将支持快速设计和高灵敏度的生物传感器。