Study On The Determination Of Uranium And ATP With Wireless Sensing Method And Fluorescence Spectrometry Based On Double-receptor Sandwich Structure

In the introductory part of this paper, we firstly introduce the methods ofdetermining uranium and their development. Then the properties and primarydetection methods of ATP are narrated. In the end, we summarize the basic structureand work principle as well as the research development of wireless magnetoelasticsensors.In the second part, a new composite type of magnetic nanoparticles for theselective separation of uranyl from aqueous solution is introduced. The nanoparticleswere prepared by coating phosphorylated polyvinyl alcohol on the surface of Fe3O4nanoparticles. We have studied the adsorption property and selective recognitionability of the nanoparticles by equilibrium-adsorption method. We have alsoinvestigated the influence of experimental conditions to the adsorption property. Thestudied results show that in the presence of competitor metal ions, the magneticnanoparticles have high adsorption and selective recognition ability to uranium.In the third part, we report a new wireless sensing method for the detection ofuranium in water samples. The method is based on a sandwich-type detection strategy.Salophen, a tetradentade ligand of uranyl ion, was immobilized on the surface of thepolyurethane-protected magnetoelastic sensor as receptor for the capture of uranyl ion.The phosphorylated polyvinyl alcohol coated magnetic Fe3O4nanoparticles were usedas signal-amplifying tags of uranyl ion. After uranyl ion was captured on the sensorsurface, the nanoparticles were bound to the sensor surface through the coordinationof uranyl with the phosphate group, resulting in enhanced mass loading on the sensorsurface that in turn decreases its resonance frequency allowing quantification ofuranium concentration. The experimental results demonstrate that this method hasmany advantages such as convenient operation, good selectivity, high sensitivity and low cost. Under optimal conditions the sensor shows a linear response to uranium, thelinear range for detection of uranium is0.2~20.0μg/L with a detection limit of0.11μg/L. The method has been applied to determine uranium in environmental watersamples with satisfactory results.In the fourth part, a double–receptor sandwich method for the fluorescencedetermination of adenosine triphosphate (ATP) is proposed. The solid phase receptoron the surface of glass slides is a molecularly imprinted membrane (MIM) containingartificial nanocavity. It is constructed by molecular imprinting technique usingadenosine monophosphate (AMP) as template molecule. The labeled receptor is auranyl-salophen complex containing fluorescent group, or uranyl-salophen-fluorescein (USF). It is synthesized with salophen,5-aminofluorescein and uranyl. Ina procedure of determining ATP, ATP in sample solution is first adsorbed on thesurface of the glass slide through the combination of AMP group in ATP with thenanocavity in MIM. Then the adsorbed ATP binds USF through the coordinationreaction of phosphate group in ATP with uranyl in USF to form a sandwich-typestructure of MIM-ATP-USF. The amount of ATP is detected through the fluorescencedetermination of USF bound on the slide. Under optimal conditions, the linear rangefor the determination of ATP is0.3to4.8nmol/mL with a detection limit of0.041nmol/mL. The proposed method has been successfully applied for the determinationof ATP in real samples with the recoveries of98.5%~102.5%.