title: Disposable bioluminescence-based biosensor for detection of bacterial count in food.
abstract: A biosensor for rapid detection of bacterial count based on adenosine 5'-triphosphate (ATP) bioluminescence has been developed. The biosensor is composed of a key sensitive element and a photomultiplier tube used as a detector element. The disposable sensitive element consists of a sampler, a cartridge where intracellular ATP is chemically extracted from bacteria, and a microtube where the extracted ATP reacts with the luciferin-luciferase reagent to produce bioluminescence. The bioluminescence signal is transformed into relevant electrical signal by the detector and further measured with a homemade luminometer. Parameters affecting the amount of the extracted ATP, including the types of ATP extractants, the concentrations of ATP extractant, and the relevant neutralizing reagent, were optimized. Under the optimal experimental conditions, the biosensor showed a linear response to standard bacteria in a concentration range from 10(3) to 10(8) colony-forming units (CFU) per milliliter with a correlation coefficient of 0.925 (n=22) within 5min. Moreover, the bacterial count of real food samples obtained by the biosensor correlated well with those by the conventional plate count method. The proposed biosensor, with characteristics of low cost, easy operation, and fast response, provides potential application to rapid evaluation of bacterial contamination in the food industry, environment monitoring, and other fields.
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100080, PR China.
authors.forename: Jinping
authors.initials: J
authors.lastname: Luo
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liu
authors.forename: Qing
authors.initials: Q
authors.lastname: Tian
authors.forename: Weiwei
authors.initials: W
authors.lastname: Yue
authors.forename: Jing
authors.initials: J
authors.lastname: Zeng
authors.forename: Guangquan
authors.initials: G
authors.lastname: Chen
authors.forename: Xinxia
authors.initials: X
authors.lastname: Cai
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis / Q000302:isolation & purification; D000818:Animals; D001419:Bacteria / Q000737:chemistry / Q000302:isolation & purification*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002138:Calibration; D015169:Colony Count, Microbial; D004209:Disposable Equipment; D005504:Food Analysis; D005516:Food Microbiology; D008163:Luminescent Measurements; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D000255:Adenosine Triphosphate