Abstract
Micro-fabrication, electrochemical characterization and analytical application of nano-composite based thin-film Cs (I) micro-sensor were presented. The new microchip was realized by integration of potassium zinc hexacyanoferrate(II) (PZHCF) nano-cubes embedded in multi-walled carbon nanotubes (CNTs) as a nano-composite sensitive layer on a treated surface of thin-film gold square planner substrate. The novel nano-composite based micro-sensor provides high sensitivity (61 +/- 0.5 mV/concentration decade) towards cesium ions covering the concentration range of 1 x 10(-11) x 10(-5) mol L-1 with fast response time (<20 s), reasonable long-term stability and long life span (>4 months). The developed micro-sensor provides high selectivity for Cs+ in comparison with some tested alkali, alkaline earth and transition metal cations. It was successfully applied in the determination of Cs+ in aqueous solutions. The data obtained reveal high agreement with those obtained with ICP-AES, good accuracy (average recovery of 99.6 %) and high precision (RDS < 1.0 %).