Design and Characteristics of an Optical Nanosensor Based on Immobilization of MWCNTs-g-PCA-Au on a Triacetylcellulose Membrane for Determination Trace Amounts of Thiourea

摘要

The characterization of an optical absorption based one-shot sensor is described for the determination of thiourea based on the immobilization of new nanocomposite of MWCNT-graft-poly(citric acid)/Au on a triacetylcellulose membrane. MWCNT-g-PCA/Au is covalently bonded to a transparent triacetylcellulose film. Thiourea reacts with the immobilized nanocomposite and causes a decrease in the absorbance of the film at 300 nm. The response time of sensing phase is within 5 min depending on the concentration of thiourea. This sensing phase has a linear range of 40-250 and 250-1000 mgL~(-1) for thiourea with a limit of detection of 11 mgL~(-1) at a wavelength of 300 nm. The nanosensor was successfully applied for the determination of thiourea in spring water and orange peel.