title: Sensitive detection of maltose and glucose based on dual enzyme-displayed bacteria electrochemical biosensor.
abstract: Glucoamylase-displayed bacteria (GA-bacteria) and glucose dehydrogenase-displayed bacteria (GDH-bacteria) were co-immobilized on multi-walled carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE) to construct GA-bacteria/GDH-bacteria/MWNTs/GCE biosensor. The biosensor was developed by optimizing the loading amount and the ratio of GA-bacteria to GDH-bacteria. The as-prepared biosensor exhibited a wide dynamic range of 0.2-10mM and a low detection limit of 0.1mM maltose (S/N=3). The biosensor also had a linear response to glucose in the range of 0.1-2.0mM and a low detection limit of 0.04mM glucose (S/N=3). Interestingly, at the same concentration, glucose was 3.75-fold sensitive than that of maltose at the proposed biosensor. No interferences were observed for other possible mono- and disaccharides. The biosensor also demonstrated good long-term storage stability and repeatability. Further, using both GDH-bacteria/MWNTs/GCE biosensor and GA-bacteria/GDH-bacteria/MWNTs/GCE biosensor, glucose and maltose in real samples can be detected. Therefore, the proposed biosensor is capable of monitoring the food manufacturing and fermentation process.
authors: Institute for Biosensing, and College of Chemistry and Chemical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071, China; Key Laboratory for Biosensors of Shangdong Province, China. Electronic address: liuah@qdu.edu.cn.
authors: Aihua
authors: A
authors: Liu
authors: Institute for Biosensing, and College of Chemistry and Chemical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071, China; Key Laboratory for Biosensors of Shangdong Province, China; Laboratory for Biosensing, Qingdao Institute of Bioenergy & Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China.
authors: Qiaolin
authors: Q
authors: Lang
authors: Laboratory for Biosensing, Qingdao Institute of Bioenergy & Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China.
authors: Bo
authors: B
authors: Liang
authors: Key Laboratory for Biosensors of Shangdong Province, China.
authors: Jianguo
authors: J
authors: Shi
mesh_terms: D001419:Bacteria / Q000201:enzymology*; D001628:Beverages / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods; D004800:Enzymes, Immobilized / Q000378:metabolism; D005504:Food Analysis / Q000379:methods; D005087:Glucan 1,4-alpha-Glucosidase / Q000378:metabolism*; D005947:Glucose / Q000032:analysis* / Q000378:metabolism; D042843:Glucose 1-Dehydrogenase / Q000378:metabolism*; D057230:Limit of Detection; D008320:Maltose / Q000032:analysis* / Q000378:metabolism; D037742:Nanotubes, Carbon / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D008320:Maltose; D042843:Glucose 1-Dehydrogenase; D005087:Glucan 1,4-alpha-Glucosidase; D005947:Glucose
keywords: Glucoamylase displayed bacteria; Glucose and maltose detection; Glucose dehydrogenase displayed bacteria; Maltose biosensor; Saccharide analysis