Amperometric Sensor Used for Determination of Thiocyanate with a Silver Nanoparticles Modified Electrode

A novel electrode modified with silver nanoparticles was fabricated. It is found that the reducibility of silver nanoparticles is higher than for bulk silver by comparing a silver nanoparticles modified electrode with a silver micro-disk electrode. When SCN- was added, a new oxidation peak occurred and the anodic peak current of silver nanoparticles decreased. The new anodic peak current is proportional to the thiocyanate concentration in the range of 5.0×10-7~4.0×10-4 mol/L in pH 6.0 NaH2PO4-Na2HPO4 buffer solutions (PBS). The detection limit (S/N=3) is 4×10-8 mol/L. This method has been applied to the determination of saliva (smoker and non-smoker).