title: A novel electrochemical sensing strategy for rapid and ultrasensitive detection of Salmonella by rolling circle amplification and DNA-AuNPs probe.
abstract: A novel electrochemical sensing strategy was developed for ultrasensitive and rapid detection of Salmonella by combining the rolling circle amplification with DNA-AuNPs probe. The target DNA could be specifically captured by probe 1 on the sensing interface. Then the circularization mixture was added to form a typical sandwich structure. In the presence of dNTPs and phi29 DNA polymerase, the RCA was initiated to produce micrometer-long single-strand DNA. Finally, the detection probe (DNA-AuNPs) could recognize RCA product to produce enzymatic electrochemical signal. Under optimal conditions, the calibration curve of synthetic target DNA had good linearity from 10aM to 10pM with a detection limit of 6.76aM (S/N=3). The developed method had been successfully applied to detect Salmonella as low as 6CFUmL(-1) in real milk sample. This proposed strategy showed great potential for clinical diagnosis, food safety and environmental monitoring.
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Pinhua
authors.initials: P
authors.lastname: Lei
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China; The Center for Clinical Molecular Medical detection, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China; State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093, PR China.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China. Electronic address: dingshijia@163.com.
authors.forename: Shijia
authors.initials: S
authors.lastname: Ding
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D015374:Biosensing Techniques / Q000191:economics / Q000379:methods*; D004269:DNA, Bacterial / Q000032:analysis* / Q000235:genetics; D055664:Electrochemical Techniques / Q000191:economics / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008892:Milk / Q000382:microbiology*; D021141:Nucleic Acid Amplification Techniques / Q000191:economics / Q000379:methods; D012475:Salmonella / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; C075518:invA protein, Bacteria; D006046:Gold
keywords: Electrochemical biosensor; Gold nanoparticles; InvA gene; Rolling circle amplification; Salmonella