title: MWCNTs based high sensitive lateral flow strip biosensor for rapid determination of aqueous mercury ions.
abstract: Here, we describe a disposable multi-walled carbon nanotubes (MWCNTs) labeled nucleic acid lateral flow strip biosensor for rapid and sensitive detection of aqueous mercury ions (Hg(2+)). Unlike the conventional colloidal gold nanoparticle based strip biosensors, the carboxylated MWCNTs were selected as the labeling substrate because of its high specific surface area for immobilization of recognition probes, improved stability and enhanced detection sensitivity of the strip biosensor. Combining the sandwich-type of T-Hg(2+)-T recognition mechanism with the optical properties of MWCNTs on lateral flow strip, optical black bands were observed on the lateral flow strips. Parameters (such as membrane category, the MWCNTs concentration, the amount of MWCNT-DNA probe, and the volume of the test probe) that govern the sensitivity and reproducibility of the sensor were optimized. The response of the optimized biosensor was highly linear over the range of 0.05-1ppb target Hg(2+), and the detection threshold was estimated at 0.05 ppb within a 15-min assay time. The sensitivity was 10-fold higher than the conventional colloidal gold based strip biosensor. More importantly, the stability of the sensor was also greatly improved with the usage of MWCNTs as the labeling.
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 230009, China.
authors.forename: Li
authors.initials: L
authors.lastname: Yao
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 230009, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Teng
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 230009, China.
authors.forename: Mengya
authors.initials: M
authors.lastname: Zhu
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 230009, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zheng
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 230009, China.
authors.forename: Youhao
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58105, United States.
authors.forename: Guodong
authors.initials: G
authors.lastname: Liu
authors.affiliation: Jiangsu Entry-Exit Inspection and Quarantine Bureau, Nanjing 200002, PR China. Electronic address: xuef1@jsciq.gov.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Xue
authors.affiliation: School of Biotechnology and Food Engineering, Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology, Hefei 230009, China. Electronic address: chenweishnu@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D015374:Biosensing Techniques / Q000191:economics / Q000295:instrumentation*; D002413:Cations, Divalent / Q000032:analysis; D004247:DNA / Q000737:chemistry; D004867:Equipment Design; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D011934:Reagent Strips / Q000032:analysis*; D015203:Reproducibility of Results; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002413:Cations, Divalent; D037742:Nanotubes, Carbon; D011934:Reagent Strips; D014874:Water Pollutants, Chemical; D014867:Water; D004247:DNA; D008628:Mercury
keywords: Carbon nanotube; Hg(2+) detection; Lateral flow strip; Sensitivity enhancement; Stability improvement