Ultra-sensitive direct detection of silver ions via Kelvin probe force microscopy.
Nanotoxicity is receiving great importance due to its potential impact on human health and environment and due to rapid development in the field of nanoscale research and industry. Herein, we report the Kelvin probe force microscope (KPPM)-based nanotoxicity material detection using surface potential difference. In general, it is difficult to measure the size of ion (Ag(+)) using a conventional atomic force microscope (AFM) because of the limited resolution. In this study, we have demonstrated that KPFM is capable of ultra-sensitive detection of silver ion with silver specific DNA by a single droplet. Furthermore, the measured surface potentials for Ag+ and DNA binding enable the detection performance for a practical sample that is general drinking water. Remarkably, the KPFM based silver ion detection enables an insight into the coordination chemistry, which plays an important role in early detection of toxicity. This implies that KPFM based detection system opens a new avenue for water testing sensor.
Department of Control and Instrumentation Engineering, Korea University, Jochiwon 339-700, Republic of Korea.
Jinsung
J
Park
Department of Mechanical Engineering, Korea University, Seoul 136-701, Republic of Korea.
Sangmyung
S
Lee
Department of Mechanical Engineering, Korea University, Seoul 136-701, Republic of Korea.
Kuewhan
K
Jang
Department of Mechanical Engineering, Korea University, Seoul 136-701, Republic of Korea. Electronic address: nass@korea.ac.kr.
Sungsoo
S
Na
D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000379:methods*; D004247:DNA / Q000032:analysis / Q000737:chemistry*; D007477:Ions; D018625:Microscopy, Atomic Force / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012834:Silver / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D007477:Ions; D014874:Water Pollutants, Chemical; D012834:Silver; D004247:DNA
DNA–metal interaction; Kelvin probe force microscope; Silver ion; Single droplet; Surface potential