Selective and sensitive electrochemical detection of glucose in neutral solution using platinum-lead alloy nanoparticle/carbon nanotube nanocomposites.
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.
Cui
Hui-Fang
HF
Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543.
Ye
Jian-Shan
JS
Zhang
Wei-De
WD
Li
Chang-Ming
CM
Luong
John H T
JH
Sheu
Fwu-Shan
FS
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
D000497:Alloys; D037742:Nanotubes, Carbon; D012996:Solutions; D007854:Lead; D010984:Platinum; D005947:Glucose