Biosensing properties of diamond and carbon nanotubes.
The biochemical properties of boron-doped diamond (BDD), carbon nanofiber, fullerene, and multiwalled carbon nanotube (MWCNT) electrodes have been investigated comparatively. Physiochemical factors which affect the biosensing properties such as surface hydrophobicities, effective surface area, and intrinsic material properties are studied. Voltammetric responses of the as-grown thin film electrode and surface-modified electrode to biomolecules such as L-ascorbic acid (L-AA), dopamine (DA), and uric acid are examined. As-grown MWCNT electrodes exhibit selective voltammetric responses to the different biomolecules and faster electron-transfer kinetics compared to BDD. The selective response is due to the considerably lower anodic potential of L-AA on MWCNT (-48 mVvs Ag/AgCl compared to 575 mV on BDD). This electrocatalytic response can be replicated on a nonselective carbon nanofiber electrode by coating it with gold nanoparticles. BDD has no intrinsic selective response to L-AA, and surface modification by anodic polarization is necessary for resolving L-AA and DA.
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.
Wei Choong
WC
Poh
Kian Ping
KP
Loh
Wei
W
De Zhang
Sudhiranjan
S
Triparthy
Jian-Shan
JS
Ye
Fwu-Shan
FS
Sheu
D001205:Ascorbic Acid / Q000032:analysis / Q000737:chemistry; D015374:Biosensing Techniques; D001895:Boron / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D018130:Diamond / Q000737:chemistry*; D004298:Dopamine / Q000032:analysis / Q000737:chemistry; D004566:Electrodes; D057927:Hydrophobic and Hydrophilic Interactions; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D013059:Spectrum Analysis, Raman; D014527:Uric Acid / Q000032:analysis / Q000737:chemistry
D037742:Nanotubes, Carbon; D014527:Uric Acid; D018130:Diamond; D001895:Boron; D001205:Ascorbic Acid; D004298:Dopamine