Graphene oxide modified H4L-ion imprinting electrochemical sensor for the detection of uranyl ions

The rapid development of the nuclear industry has gradually aroused people′s attention to the problem of nuclear pollution. Due to the biological toxicity of uranium and its aqueous solution, simple and rapid detection of uranium in the water environment is quite important. An ion imprinted carbon nanomaterial (graphene oxide) electrochemical sensor for the detection of trace uranyl ions was prepared by using the synthesized bipolar tetradentate macrocyclic uranyl ligand cyclo-bis-phenylenediamine-bis-(phenylmethyl-diphyrrolecarbaldehyde) (H 4 L) as functional monomer. The sol-gel polymer was prepared by hydrolysis and polymerization of H 4 L ligand, 3-aminopropyltrimethoxysilane and tetraethoxysilane. H 4 L-ion imprinted polymer (U-IIP) was prepared by adding 1 mM uranyl ion as template ions. Then the polymer was bonded to graphene oxide modified carbon paste electrode, and the template ions were eluted to obtain H 4 L-ion imprinted-graphene oxide modified carbon paste electrode (U-IIP/GO/CPE). Differential pulse voltammetry was used to detect trace uranyl ions. The results showed that the U-IIP/GO/CPE sensor system can detect uranyl ions with high sensitivity and specificity, and the peak current appeared around −0.26v. In the range of 0.01 μM∼3.0 μM, the detection current had a good linear relationship with the molar concentration of uranyl ions, and the method detection limit was 1.32 nM (S/N=3). Through the detection of actual samples, it had a good acceptable recovery rate (95.45 %∼106.25 %), and the relative standard deviation was less than 3.25 %.