Design And Sensing Performance Of Detection Probes For Uranyl Ions In The Aqueous Environment

As the major source of raw materials for the development of the nuclear industry,uranium mines require extra rigorous regulation for their construction,mining and ecological management,which is an inherent requirement for sustainable development and a necessary condition for the health and safety of personnel.How to detect radioactive elements such as uranium in the aquatic environment of uranium mines has been a hot topic in the field of environmental protection.At the same time,efficient and accurate target detection has been an unwavering development goal of identification sensing.In comparison to high-precision but expensive detection instruments,developing an affordable and practical uranyl ion detection sensor with an excellent detection limit is critical.This paper investigated and discussed convenient,sensitive,and efficient detection sensors for trace uranyl ions.In the first part,a graphene oxide modified electrode was designed and explored in combination with the schiff base functional compound H₄L to develop an electrochemical probe for the determination of trace amounts of UO₂²⁺.The UIIP-GO-CPE and NIIP-GO-CPE were prepared by adding the template marker(UO₂²⁺)and replacing the marker with an equivalent amount of ultrapure water,respectively.The experiment showed that the modified electrode UIIP-GO-CPE with signal amplification and particular identification features was proven to significantly improve the sensing ability to capture uranyl ions.The UO₂²⁺cations in the electrolyte were captured by the cathodic modified electrode during electrolysis,and electrons were absorbed to produce a reduction reaction,which caused a change in the pulsed voltammetric signal.In contrast to the NIIP-GO-CPE system,which did not generate a response signal,the newly developed UIIP-GO-CPE sensor had the ability to detect traces of UO₂²⁺in the aqueous environment.The response signal was linear in the range of 0.01～3μM with a method detection limit of 1.32 n M.In the second part,rifampicin and 2-（5-bromo-2-pyridyllazo）-5-（diet hylamino）phenol were used as color-developing agents,respectively,and when they interacted with uranyl ions to form complexes,they caused significant color variety.Then,using the constructed colorimetric viewfinder combined with a smartphone to extract digital photos,and using the developed Android detection software to evaluate the HSV and HSL data,the concentration range of trace UO₂²⁺can be predicted at the detection site.In addition,the intervention of UV spectrometer enabled more accurate laboratory concentration analysis,and the final detection results met expectations.The two systems also showed a good linear relationship with the concentration of uranyl ions.Among them,the absorbance of the rifampicin system had a linear relationship with the concentration of uranyl ions in the range of 4-50μM at 375 nm,and the method detection limit of the UV-vis-based was 3.17μM.There was a linear relationship between the absorbance of 2-（5-bromo-2-pyridylazo）-5-（diethylamino）phenol system and uranyl ion concentration in the range of 0.9-7μM at 562 nm,and the method detection limit of UV-vis-based was 0.89μM.Furthermore,the combination of the two schemes enables the detection of a wider range of UO₂²⁺concentrations and has been successfully applied to the analysis of real samples such as soils around uranium mines and aqueous samples.