Improvement of a highly sensitive and specific whole-cell biosensor by adding a positive feedback amplifier

查看全文 作　　者：Shuting [1]Hu;Guangbao [1]Zhang;Xiaoqiang [1,2,3]Jia 机构地区：[1]Department of Biochemical Engineering,School of Chemical Engineering and Technology,Tianjin University,Tianjin,300072,PR China;[2]Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education),School of Chemical Engineering and Technology,Tianjin University,Tianjin,300350,PR China;[3]Collaborative Innovation Center of Chemical Science and Engineering(Tianjin),Tianjin,300072,PR China 出　　处：《Synthetic and Systems Biotechnology》索引2023年第8卷第2期,共8页 基　　金：support provided by the National Key Research and Development Program of China(2018YFA0902100);the National Natural Science Foundation of China(21576197). 摘　　要：In this study,we designed a Cd^(2+)whole-cell biosensor with both positive and negative feedback cascade am-plifiers in Pseudomonas putida KT2440(LTCM)based on our previous design with only a negative feedback amplifier(TCM).The results showed that the newly developed biosensor LTCM was greatly improved compared to TCM.Firstly,the linear response range of LTCM was expanded while the maximum linear response range was raised from 0.05 to 0.1μM.Meanwhile,adding a positive feedback amplifier further increased the fluorescence output signal of LTCM 1.11–2.64 times under the same culture conditions.Moreover,the response time of LTCM for detection of practical samples was reduced from 6 to 4 h.At the same time,LTCM still retained very high sensitivity and specificity,while its lowest detection limit was 0.1 nM Cd^(2+)and the specificity was 23.29(compared to 0.1 nM and 17.55 in TCM,respectively).In summary,the positive and negative feedback cascade amplifiers effectively improved the performance of the biosensor LTCM,resulting in a greater linear response range,higher output signal intensity,and shorter response time than TCM while retaining comparable sensitivity and specificity,indicating better potential for practical applications. 关 键 词：Cadmium detection Positive feedback amplifier Sensitivity SPECIFICITY Whole-cell biosensor