CdS quantum dots; biosensor; urease; urea; fluorescence spectroscopy.
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India
Adv. Mater. Lett., 2013, Current Issue, 4 (5), pp 359-362
Publication Date (Web): Feb 23, 2013
Copyright © IAAM-VBRI Press
Semiconductor nanoparticles (NPs) have attracted much attention as a new class of fluorescent probe for many biological applications including biosensors for glucose, cholesterol, cysteine etc., which were based on their size dependent unique electrical and photophysical properties. One of the major challenges in fabricating nanomaterial based biosensor is conjugation of a suitable compound to quantum dots which is preferably selective to the analyte of interest. Here we report our studies on synthesis, characterization and application of jack bean meal urease immobilized on CdS quantum dots (QDs) for sensing of urea. The CdS QDs were synthesized by chemical precipitation method using Mercaptoacetic acid (MAA) for controlling size as well as for imparting functional group for conjugating urease. The urease immobilize on MAA capped CdS nanoparticle was characterized by an array of techniques, like, UV- visible, Fluorescence, XRD, FT-IR and SEM EDAX. The detection capability of urea was studied by fluorescence spectroscopy at an excitation wavelength of λex = 430 nm and emission wavelength of λem= 546 nm. This method was capable to detect urea in the concentration range of 0.1 µM to 1 mM.
CdS quantum dots, biosensor, urease, urea, fluorescence spectroscopy.