title: An integrated paper-based sample-to-answer biosensor for nucleic acid testing at the point of care.
abstract: With advances in point-of-care testing (POCT), lateral flow assays (LFAs) have been explored for nucleic acid detection. However, biological samples generally contain complex compositions and low amounts of target nucleic acids, and currently require laborious off-chip nucleic acid extraction and amplification processes (e.g., tube-based extraction and polymerase chain reaction (PCR)) prior to detection. To the best of our knowledge, even though the integration of DNA extraction and amplification into a paper-based biosensor has been reported, a combination of LFA with the aforementioned steps for simple colorimetric readout has not yet been demonstrated. Here, we demonstrate for the first time an integrated paper-based biosensor incorporating nucleic acid extraction, amplification and visual detection or quantification using a smartphone. A handheld battery-powered heating device was specially developed for nucleic acid amplification in POC settings, which is coupled with this simple assay for rapid target detection. The biosensor can successfully detect Escherichia coli (as a model analyte) in spiked drinking water, milk, blood, and spinach with a detection limit of as low as 10-1000 CFU mL(-1), and Streptococcus pneumonia in clinical blood samples, highlighting its potential use in medical diagnostics, food safety analysis and environmental monitoring. As compared to the lengthy conventional assay, which requires more than 5 hours for the entire sample-to-answer process, it takes about 1 hour for our integrated biosensor. The integrated biosensor holds great potential for detection of various target analytes for wide applications in the near future.
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China. fengxu@mail.xjtu.edu.cn and Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia. bpingguan@um.edu.my.
authors.forename: Jane Ru
authors.initials: JR
authors.lastname: Choi
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China. fengxu@mail.xjtu.edu.cn and Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Hu
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China. fengxu@mail.xjtu.edu.cn and Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
authors.forename: Ruihua
authors.initials: R
authors.lastname: Tang
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China. fengxu@mail.xjtu.edu.cn and Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gong
authors.affiliation: Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China and MOE Key Laboratory of Multifunctional Materials and Structures (LMMS), School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, PR China.
authors.forename: Shangsheng
authors.initials: S
authors.lastname: Feng
authors.affiliation: Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China and Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Ren
authors.affiliation: Xi'an Diandi Biotech Company, Xi'an 710049, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wen
authors.affiliation: Department of Chemistry, College of Health Sciences; Biomedical Engineering; & Border Biomedical Research Center, University of Texas at El Paso, El Paso, Texas 79968, USA.
authors.forename: XiuJun
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia. bpingguan@um.edu.my.
authors.forename: Wan Abu Bakar
authors.initials: WA
authors.lastname: Wan Abas
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia. bpingguan@um.edu.my.
authors.forename: Belinda
authors.initials: B
authors.lastname: Pingguan-Murphy
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China. fengxu@mail.xjtu.edu.cn and Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D004926:Escherichia coli; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D021141:Nucleic Acid Amplification Techniques / Q000295:instrumentation / Q000379:methods; D010209:Paper; D019095:Point-of-Care Systems; D013296:Streptococcus pneumoniae
chemical_list: D006046:Gold