Use of CdSe/ZnS luminescent quantum dots incorporated within sol-gel matrix for urea detection

作者：Duong Hong Dinh; Il Rhee Jong^*

来源：Analytica Chimica Acta, 2008, 626(1): 53-61.

DOI：10.1016/j.aca.2008.07.042

• urea detection
• quantum dots
• sol-gel membranes
• microtiter plate
• urease
• immobilization

In this work, urea detection techniques based on the pH sensitivity of CdSe/ZnS QDs were developed using three types of sol-gel membranes: a QD-entrapped membrane, urease-immobilized membrane and double layer consisting of a QD-entrapped membrane and urease-immobilized membrane. The surface morphology of the sol-gel membranes deposited on the wells in a 24-well microtiter plate was investigated. The linear detection range of urea was in the range of 0-10 mM with the three types of sol-gel membranes, The urea detection technique based on the double layer consisting of the QD-entrapped membrane and urease-immobilized membrane resulted in the highest sensitivity to urea due to the Michaelis-Menten kinetic parameters. That is, the Michaelis-Menten constant (K(m) =2.0745 mM) of the free urease in the QD-entrapped membrane was about 4-fold higher than that (K(m) =0.549 mM) of the immobilized urease in the urease immobilized membrane and about 12-fold higher than that (Km =0.1698 mM) of the immobilized urease in the double layer. The good stability of the three sol-gel membranes for urea. sensing over 2 months showed that the use of sol-gel membranes immobilized with QDS or an enzyme is suitable for biomedical and environmental applications.

• 出版日期2008-9-19