title: Combination of a Sample Pretreatment Microfluidic Device with a Photoluminescent Graphene Oxide Quantum Dot Sensor for Trace Lead Detection.
abstract: A novel trace lead ion (Pb(2+)) detection platform by combining a microfluidic sample pretreatment device with a DNA aptamer linked photoluminescent graphene oxide quantum dot (GOQD) sensor was proposed. The multilayered microdevice included a microchamber which was packed with cation exchange resins for preconcentrating metal ions. The sample loading and recovery were automatically actuated by a peristaltic polydimethylsiloxane micropump with a flow rate of 84 μL/min. Effects of the micropump actuation time, metal ion concentration, pH, and the volumes of the sample and eluent on the metal ion capture and preconcentration efficiency were investigated on a chip. The Pb(2+) samples whose concentrations ranged from 0.48 nM to 1.2 μM were successfully recovered with a preconcentration factor value between 4 and 5. Then, the preconcentrated metal ions were quantitatively analyzed with a DNA aptamer modified GOQD. The DNA aptamer on the GOQD specifically captured the target Pb(2+) which can induce electron transfer from GOQD to Pb(2+) upon UV irradiation, thereby resulting in the fluorescence quenching of the GOQD. The disturbing effect of foreign anions on the Pb(2+) detection and the spiked Pb(2+) real samples were also analyzed. The proposed GOQD metal ion sensor exhibited highly sensitive Pb(2+) detection with a detection limit of 0.64 nM and a dynamic range from 1 to 1000 nM. The on-chip preconcentration of the trace metal ions from a large-volume sample followed by the metal ion detection by the fluorescent GOQD sensor can provide an advanced platform for on-site water pollution screening.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Minsu
authors.initials: M
authors.lastname: Park
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Hyun Dong
authors.initials: HD
authors.lastname: Ha
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Yong Tae
authors.initials: YT
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Jung
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Shin-Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Do Hyun
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Tae Seok
authors.initials: TS
authors.lastname: Seo
mesh_terms: D006108:Graphite / Q000737:chemistry*; D056656:Lab-On-A-Chip Devices; D007854:Lead / Q000032:analysis*; D049449:Luminescence; D010087:Oxides / Q000737:chemistry; D045663:Quantum Dots
chemical_list: D010087:Oxides; D007854:Lead; D006108:Graphite