Abstract
Strontium oxide nanorods (SrO NR) were prepared in alkaline medium by a wet-chemical method. They were characterized by FTIR, UV/Vis, field emission scanning electron microscopy, X-ray electron dispersive spectroscopy, X-ray photoelectron spectroscopy and powder X-ray diffraction. A thin-layer of the NR was deposited on a glassy carbon electrode to give an electrochemical sensor for the amino acid L-leucine (L-Leu) that has good sensitivity, a wide dynamic range and good long-term stability. The response to Leu was studied by the current-voltage (I-V) technique. The calibration plot (with data acquired at +0.8 V vs. SCE) was found to cover 0.1 nM to 0.1 mM L-Leu concentration range. The sensitivity is 2.53 nAai...mu M(-1ai...)cm(-2), and the limit of detection is 37.5 +/- 0.2 pM (at a signal to noise ratio of 3). The sensor was applied to the fairly selective determination of L-Leu in spiked urine, milk, and serum samples to give acceptable results.