title: Direct electrochemistry of cytochrome c immobilized on titanium nitride/multi-walled carbon nanotube composite for amperometric nitrite biosensor.
abstract: In this report, titanium nitride (TiN) nanoparticles decorated multi-walled carbon nanotube (MWCNTs) nanocomposite is fabricated via a two-step process. These two steps involve the decoration of titanium dioxide nanoparticles onto the MWCNTs surface and a subsequent thermal nitridation. Transmission electron microscopy shows that TiN nanoparticles with a mean diameter of ≤ 20 nm are homogeneously dispersed onto the MWCNTs surface. Direct electrochemistry and electrocatalysis of cytochrome c immobilized on the MWCNTs-TiN composite modified on a glassy carbon electrode for nitrite sensing are investigated. Under optimum conditions, the current response is linear to its concentration from 1 µM to 2000 µM with a sensitivity of 121.5 µA µM(-1)cm(-2) and a low detection limit of 0.0014 µM. The proposed electrode shows good reproducibility and long-term stability. The applicability of the as-prepared biosensor is validated by the successful detection of nitrite in tap and sea water samples.
authors.affiliation: Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX 75080, USA; Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 100-715, Republic of Korea.
authors.forename: Yuvaraj
authors.initials: Y
authors.lastname: Haldorai
authors.affiliation: Department of Biological Engineering, Biohybrid Systems Research Center (BSRC), Inha University, Incheon 402-751, Republic of Korea.
authors.forename: Seung-Kyu
authors.initials: SK
authors.lastname: Hwang
authors.affiliation: Research Energy Institute of Advanced Technology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Anantha-Iyengar
authors.initials: AI
authors.lastname: Gopalan
authors.affiliation: Department of Biological Engineering, Biohybrid Systems Research Center (BSRC), Inha University, Incheon 402-751, Republic of Korea. Electronic address: yunsuk.huh@inha.ac.kr.
authors.forename: Yun Suk
authors.initials: YS
authors.lastname: Huh
authors.affiliation: Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 100-715, Republic of Korea. Electronic address: ykenergy@dongguk.edu.
authors.forename: Young-Kyu
authors.initials: YK
authors.lastname: Han
authors.affiliation: Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX 75080, USA; Alan G. MacDiarmid Nanotech Institute, University of Texas at Dallas, Richardson, TX, USA. Electronic address: walter.voit@utdallas.edu.
authors.forename: Walter
authors.initials: W
authors.lastname: Voit
authors.affiliation: School of Electronics Engineering, Kyungpook National University, Daegu 702-701, South Korea. Electronic address: gsaianandh@gmail.com.
authors.forename: Gopalan
authors.initials: G
authors.lastname: Sai-Anand
authors.affiliation: Department of Chemistry Education, Kyungpook National University, Daegu 702-701, South Korea. Electronic address: kplee@knu.ac.kr.
authors.forename: Kwang-Pill
authors.initials: KP
authors.lastname: Lee
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D045304:Cytochromes c / Q000737:chemistry*; D060766:Drinking Water / Q000032:analysis*; D055664:Electrochemical Techniques / Q000295:instrumentation; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry*; D004867:Equipment Design; D057230:Limit of Detection; D008958:Models, Molecular; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D009573:Nitrites / Q000032:analysis*; D012623:Seawater / Q000032:analysis*; D014025:Titanium / Q000737:chemistry
chemical_list: D060766:Drinking Water; D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D009573:Nitrites; C041500:titanium nitride; D045304:Cytochromes c; D014025:Titanium
keywords: Carbon nanotubes; Cytochrome c; Nanocomposite; Nitrite sensor; Titanium nitride