Gold nanoparticle-modified graphite pencil electrode for the high-sensitivity detection of hydrazine.
A novel gold nanoparticle-modified graphite pencil electrode (AuNP-GPE) is prepared just by immersing a bare GPE in AuNP solution, followed by heating for 15 min. The bare and modified GPEs are characterized by FE-SEM imaging and cyclic voltammetry. The AuNP-GPEs showed excellent electrocatalytic activities with respect to hydrazine oxidation, with good reproducibility. To reduce the quantification and detection limits, and increase the hydrazine sensitivity, the pH and square wave voltammetry parameters are optimized. A square wave voltammetry study as a function of the hydrazine concentration showed that the AuNP-GPE detector's quantification limit was 100 nmol L(-1) hydrazine, much lower than the value obtained using amperometry (10 µmol L(-1)). The limits of detection (at 3σ) for hydrazine sensing at AuNP-GPEs using square wave voltammetry and amperometry were 42 nmol L(-1) and 3.07 µmol L(-1). Finally, the modified electrode was used to determine the hydrazine concentration in drinking water, and satisfactory results are obtained. This simple, rapid, low-cost method for fabricating a modified electrode is an attractive approach to the development of new sensors.
Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
Md
M
Abdul Aziz
Abdel-Nasser
AN
Kawde
D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D006108:Graphite; D006834:Hydrazines / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D006834:Hydrazines; D014874:Water Pollutants, Chemical; C029424:hydrazine; D006046:Gold; D006108:Graphite
Gold nanoparticles; Graphite pencil electrode; Hydrazine; Sensor; Square wave voltammetry