title: Ultra-sensitive and absolute quantitative detection of Cu2+based on DNAzyme and digital PCR in water and drink samples.
abstract: Here, we developed an ultra-sensitive and absolute quantitative detection method of Cu2+based on DNAzyme and digital PCR. The binding model between DNAzyme and Cu2+and the influence caused by the additional primer sequence were revealed to ensure quantitation independent of standard curves. The binding model of DNAzyme and Cu2+showed that one molecular DNAzyme could bind one Cu2+in the biosensor step. Thus, the final quantitative results, evaluated by three parallels, showed that the limit of quantitation (LOQ) was as low as 0.5pmol, while the sensitivity was evaluated as 50fmol. The specificity evaluation of our methodologies shows that extremely low crossing signal is existed within the non-specific ions. Moreover, the results of practical detection have shown that the quantitative results were stable and accurate among different food substrates. In conclusion, a flexible quantitative detection method with ultra-sensitivity was developed to detect trace amounts Cu2+within different substrates.
authors.affiliation: Laboratory of Food Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; The Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing, 100176, China.
authors.forename: Pengyu
authors.initials: P
authors.lastname: Zhu
authors.affiliation: Laboratory of Food Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Yunnan Institute of Food Safety, Kunming University of Science and Technology, Kunming, Yunnan 650500, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Shang
authors.affiliation: Laboratory of Food Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Wenying
authors.initials: W
authors.lastname: Tian
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, China; Laboratory of Food Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Kunlun
authors.initials: K
authors.lastname: Huang
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, China.
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science & Nutritional Engineering, China Agricultural University, China; Laboratory of Food Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: xuwentao@cau.edu.cn.
authors.forename: Wentao
authors.initials: W
authors.lastname: Xu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003300:Copper / Q000032:analysis*; D021881:DNA, Catalytic; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry*
chemical_list: D021881:DNA, Catalytic; D014867:Water; D003300:Copper
keywords: Absolute quantitation; Biosensor; Copper ion; Digital PCR; Ultra-sensitive