title: Selective and sensitive electrochemical detection of glucose in neutral solution using platinum-lead alloy nanoparticle/carbon nanotube nanocomposites.
abstract: Electrodeposition of Pt-Pb nanoparticles (PtPbNPs) to multi-walled carbon nanotubes (MWCNTs) resulted in a stable PtPbNP/MWCNT nanocomposite with high electrocatalytic activity to glucose oxidation in either neutral or alkaline medium. More importantly, the nanocomposite electrode with a slight modification exhibited high sensitivity, high selectivity, and low detection limit in amperometric glucose sensing at physiological neutral pH (poised at a negative potential). At +0.30 V in neutral solution, the nanocomposite electrode exhibited linearity up to 11 mM of glucose with a sensitivity of 17.8 microA cm(-2) mM(-1) and a detection limit of 1.8 microM (S/N=3). Electroactive ascorbic acid (0.1 mM), uric acid (0.1 mM) and fructose (0.3 mM) invoked only 23%, 14% and 9%, respectively, of the current response obtained for 3 mM glucose. At -0.15 V in neutral solution, the electrode responded linearly to glucose up to 5 mM with a detection limit of 0.16 mM (S/N=3) and detection sensitivity of approximately 18 microA cm(-2) mM(-1). At this negative potential, ascorbic acid, uric acid, and fructose were not electroactive, therefore, not interfering with glucose sensing. Modification of the nanocomposite electrode with Nafion coating followed by electrodeposition of a second layer of PtPbNPs on the Nafion coated PtPbNP/MWCNT nanocomposite produced a glucose sensor (poised at -0.15 V) with a lower detection limit (7.0 microM at S/N=3) and comparable sensitivity, selectivity and linearity compared to the PtPbNP/MWCNT nanocomposite. The Nafion coating lowered the detection limit by reducing the background noise, while the second layer of PtPbNPs restored the sensitivity to the level before Nafion coating.
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543.
authors.forename: Hui-Fang
authors.initials: HF
authors.lastname: Cui
authors.forename: Jian-Shan
authors.initials: JS
authors.lastname: Ye
authors.forename: Wei-De
authors.initials: WD
authors.lastname: Zhang
authors.forename: Chang-Ming
authors.initials: CM
authors.lastname: Li
authors.forename: John H T
authors.initials: JH
authors.lastname: Luong
authors.forename: Fwu-Shan
authors.initials: FS
authors.lastname: Sheu
mesh_terms: D000497:Alloys; D004563:Electrochemistry; D004566:Electrodes; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*; D012996:Solutions
chemical_list: D000497:Alloys; D037742:Nanotubes, Carbon; D012996:Solutions; D007854:Lead; D010984:Platinum; D005947:Glucose