Spectral Detection And Removal Of Mercury Ions In The Environment

Mercury,as one of the most toxic heavy metal ions.With the continuous emission of human life and production into the environment,it causes great harm to the human living environment and physical health.Many platforms have been developed for the detection and removal of mercury ions.However,due to the complexity and diversity of the components in the environment,the detection results and efficiency of these methods are not optimistic.Therefore,the development of multifunctional platforms to simultaneously detect and remove mercury remains a major challenge in the field of environmental pollution control.In view of the above problems,this paper designs SERS sensor and multifunctional polystyrene particles to realize the detection of mercury ions and methyl mercury ions respectively,and the detection and efficient removal of mercury ions.The main contents are as follows:（1）In this chapter,a SERS sensor with surface modified 4-mercaptophenylboric acid（4-MPBA）gold nanorods array was designed.The sensor performs well for the detection of Hg²⁺and CH₃Hg⁺.Gold nanorods（Au NRs）,due to their unique surface plasmon resonance（SPR）properties,have a significant ability to absorb and scatter light,arranged in a tight and uniform array,which can greatly enhance the Raman signal.4-MPBA as a Raman molecule can not only provide specific signals,but also capture the Raman signal change of Hg²⁺and CH₃Hg⁺due to its structural characteristics,realizing the conversion from ion concentration to SERS signal.Under the optimized experimental conditions,the sensor detection of Hg²⁺yielded good linear relations in the range of 100n M to 100μM,with a detection limit of 75.83 n M.The detection of CH₃Hg⁺showed a good linear relationship between 1μM and 40μM and obtained a detection limit of 74.75 n M.The sensor is not disturbed by the environment and is excellent in the detection of real water samples.At the same time,the reproducibility of the sensor is extremely high,which can provide a new idea for other SERS sensor design.（2）In this chapter,a novel polystyrene microsphere functionalized by L-cysteine with special fluorescence scattering effect was constructed by a simple one-step reaction.The multifunctional platform is superior in mercury ion removal and detection.Polystyrene-L-cysteine（PS-LCYS）has a large number of active sites（-SH/-NH₂/-OH）,which can cooperate with Hg²⁺to form new complexes(PS-LCYS-Hg²⁺)for the purpose of removal.The enhancement of second-order scattering upon addition of Hg²⁺,indicates that PS-LCYS can be used to detect Hg²⁺.As expected,this strategy achieves a low detection limit of 85 n M over a large range of 50-1700μM.Meanwhile,target-induced aggregation enabled PS-LCYS to effectively encapsulate Hg²⁺,with good absorption of 92.69%-94.32%of the mercury ions in 10 min.The maximum Hg²⁺uptake capacity of PS-LCYS was estimated to be 1314 mg/g.Furthermore,the platform can be reused by regeneration after EDTA treatment,with a removal rate of 88.54%after 7 cycles.This method develops a versatile platform for the simultaneous detection and removal of heavy metal pollution in environmental monitoring and improvement.