Silver coated quartz crystal microbalance resonator were covered with CuO nanostructures

Both sides (5 mm in diameter) of a silver-coated quartz crystal microbalance (QCM) resonator were covered with CuO nanostructures; the resonator was used as a sensing probe in a quartz crystal resonator. The resonant frequency shift indicates the absorbance of HCN gas on the sensor. As the specific area of CuO nanostructure used for coating the probe changes from 9.3 m2/g to 1.5 m2/g, the sensitivity reduces from 2.26 to 0.31 Hz/μg. In both reports, the authors showed that the sensitivity of sensors depends not only on the surface area but also on the morphology of the nanostructure. The variation in the chemical reactivity of different crystal planes could explain the change in the sensitivity of other nanostructures. Glucose detection is another important application of CuO in the sensing field. In conventional methods, glucose detection is based on the use of glucose oxidase, which is an enzyme used in the sensor. This enzyme catalyzes the oxidation of glucose to gluconolactone and simultaneously produces H2O2. Glucose level is then evaluated by estimation from electrochemical response to the liberated H2O2. However, the main disadvantages of conventional methods are high cost and lack of enzyme stability, complicated immobilization procedures of enzymes, and the coexisting interferences in the biological fluids together with critical operating conditions. Most limitations could be solved using CuO nanostructures as an alternative oxidase. CuO nanomaterials act as catalysts to convert glucose into gluconolactone and finally to glucose acid. The better efficiency of the oxidized reaction in CuO-based sensors resulted from the high surface area and surface energy, which enhanced the electron transfer ability of CuO nanomaterials. If you are looking for high quality, high purity, and cost-effective copper oxide, or if you require the latest price, please email contact mis-asia.