在这里,我们报告了一种概念验证藻类细胞传感器,用于电化学定量废水中的细菌,利用固定在炭黑(CB)纳米改性丝网印刷电极上的绿色光合藻类衣藻。CB纳米粒子用作纳米修饰剂,因为它们能够感知藻类产生的氧气,因此当藻类暴露于浓度不断增加的细菌时,电流会增加。该传感器在标准溶液和实际废水样品上进行了测试,以检测100至2000CFU/100mL的线性响应范围内的大肠杆菌。检测限为92CFU/100mL,符合意大利法律规定的废水最大大肠杆菌浓度(小于5000CFU/100mL)。该细菌被用作藻类细胞传感器的案例研究目标,以证明其作为预警分析系统的能力,以发出离开废水处理厂的水中大量病原体的信号。的确,细胞传感器对大肠杆菌没有选择性,但它能够通过利用它们相互作用的作用来感测诱导藻类氧气释放的所有细菌。其他已知的毒物,通常存在于废水中,还进行了分析以测试细胞传感器的选择性,有任何显著的效果,除了阿特拉津,它是衣藻光系统II的D1蛋白的特定靶标。然而,后者也可以通过叶绿素荧光同时检测到安培测量。评估了基质效应,1000CFU/100mL大肠杆菌在Lignano中的回收率分别为105±8、83±7和88±7%,圣乔治,和佩斯卡拉废水样本,分别。
Herein, we report a proof-of-concept algal cytosensor for the electrochemical quantification of bacteria in wastewater, exploiting the green photosynthetic alga Chlamydomonas reinhardtii immobilized on carbon black (CB) nanomodified screen-printed electrodes. The CB nanoparticles are used as nanomodifiers, as they are able to sense the oxygen produced by the algae and thus the current increases when algae are exposed to increasing concentrations of bacteria. The sensor was tested on both standard solutions and real wastewater samples for the detection Escherichia coli in a linear range of response from 100 to 2000 CFU/100 mL, showing a limit of detection of 92 CFU/100 mL, in agreement with the maximum E. coli concentration established by the Italian law for wastewater (less than 5000 CFU/100 mL). This bacterium was exploited as a
case study target of the algal cytosensor to demonstrate its ability as an early warning analytical system to signal heavy loads of pathogens in waters leaving the wastewater treatment plants. Indeed, the cytosensor is not selective towards E. coli but it is capable of sensing all the bacteria that induce the algae oxygen evolution by exploiting the effect of their interaction. Other known toxicants, commonly present in wastewater, were also analyzed to test the cytosensor selectivity, with any significant effect, apart from atrazine, which is a specific target of the D1 protein of the Chlamydomonas photosystem II. However, the latter can also be detected by chlorophyll fluorescence simultaneously to the amperometric measurements. The matrix effect was evaluated, and the recovery values were calculated as 105 ± 8, 83 ± 7, and 88 ± 7% for 1000 CFU/100 mL of E. coli in Lignano, San Giorgio, and Pescara wastewater samples, respectively.