Mn-doped ZnS QDs Surface Molecularly Imprinted Polymer Phosphorescence Selective Recognition And Detection Of Phenol Performance

The development of machinery industry aims for new type of mechanical products,efficient production process and improving productivity.At the same time,how to reduce production energy consumption of resources and how to monitor,control or even eliminate the mechanical industrial production pollution to the ecological environment problem are becoming a top priority for the future development of mechanical engineering disciplines.For example,the phenolic wastewater is one of the largest industrial wastewater pollution in the environment.In the process of steel smelting,coking process and surface coating process machinery,machinery industry production of coking produces a lot of phenol wastewater every year and the toxicity is very huge and serious.It has been listed in one of the three key sewage disposal projects of iron and steel production industry.Therefore,how to quickly,effectively and easily detect whether the phenol residues in the steel and machinery industry has a practical application value in the discharge standard.The paper with phosphorescence properties of ZnS Quantum Dots(QDs),uses surface molecular imprinting technique(SMIT)to anchor three different MIPs as the RTP probe on the surface of MPTS capped Mn dopped ZnS QDs(MPTS-ZnS QDs: Mn).They are MPTS-ZnS QDs:Mn@SiO2@ms-MIPs,KH-570-MPTS-ZnS QDs: Mn@MIPs,MPTS-ZnS QDs:Mn@MIPs.MIPs characteristic functional groups,microstructure morphology and optical properties were characterized by using Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),transmission electron microscope(TEM),spectrofluorometer and UV-vis spectrophotometer.The recognition mechanism was discussed and the actual water sample was used.The specific research results of this paper are as follows:(1)Study on preparation and performance of MPTS-ZnS QDs: MnUsing water phase coprecipitation has prepared MPTS-ZnS QDs: Mn(basic luminescent materials).The experimental results show that the particle size of MPTS-ZnS QDs: Mn is about 3.8197 nm,and compared with ZnS QDs: Mn,its phosphorescence stability is improved effectively.MPTS-ZnS QDs: Mn has a wide excitation spectrum,and its excitation wavelength is 320 nm,and the emission wavelength is 590 nm.Further determination of phosphorescence quenching of MPTSZnS QDs: Mn and phenol is non-radiation energy transfer,based on the excitation spectra of MPTS-ZnS QDs: Mn and UV absorption of phenol.(2)Study on preparation and performance of MPTS-ZnS QDs: Mn@SiO2@MIPs and MPTS-ZnS QDs: Mn@SiO2@ms-MIPsDuring the sol-gel process,MPTS-ZnS QDs: Mn acts as luminophore,and phenol acts as template molecule to obtain MPTS-ZnS QDs: Mn@SiO2@MIPs,at the same time,CTAB acts as surfactant to obtain mesoporous structured MPTS-ZnS QDs: Mn@SiO2@ms-MIPs.Experimental results show that MPTS-ZnS QDs: Mn@SiO2@ms-MIPs has a mesoporous structure and its room-temperature phosphorescence performance is stable.The concentration range of detection phenol is from 5.0 μmol/L to 50 μmol/L.The correlation coefficient is 0.9983.The best detection concentration of MPTS-ZnS QDs: Mn@SiO2@ms-MIPs is 30 mg/L.The optimal detection time is 20 min,and imprinting factor(IF)is 3.28.It has a lower detection limit(LOD)of 1.40 μmol/L.The relative standard deviation of MPTS-ZnS QDs: Mn@SiO2@ms-MIPs to phenol test is 1.6% to 3.2%,which can be applied to the detection of phenol in actual water samples.(3)Study on preparation and performance of KH-570-MPTS-ZnS QDs: Mn@MIPsTo achieve KH-570-MPTS-ZnS QDs: Mn@MIPs,the film MIPs are grafted onto the surface of vinyl modified MPTS-ZnS QDs: Mn via gradual precipitation polymerization.Phenol is template molecule.The experimental results show that,through the gradual precipitation polymerization,KH-570-MPTS-ZnS QDs: Mn@MIPs do not change the original crystal structure.The concentration range of detection phenol is from 5.0 μmol/L to 55 μmol/L.The IF is 3.43 and the correlation coefficient is 0.9984.The optimum detection concentration is 38 mg/L,the optimal detection time is 20 min,and the LOD is 2.13 μmol/L.The RSD of KH-570-MPTSZnS QDs: Mn@MIPs to phenol test is 1.4% to 3.7%,which can be applied to the detection of phenol in actual water samples.(4)Study on preparation and performance of MPTS-ZnS QDs: Mn@MIPsBased on the high-controllable atom transfer radical polymerization,MPTS-ZnS QDs: Mn are used as the nucleus matrix and sensing nanomaterial.By adding α-Bromoisobutyryl bromide,the –Br is grafted onto the chain of silane modified ZnS QDs: Mn to synthesize MPTS-ZnS QDs: Mn-NH2-Br as initiator during the ATRP.The CuBr acts as the catalyst and phenol acts as template molecule.The experimental results show that the optimal detection concentration and optimal detection time are 24 mg/L and 25 min,respectively.The concentration range of detection phenol is from 5.0 μmol/L to 50 μmol/L.The IF is 3.23 and the correlation coefficient is 0.9979.The LOD is 1.72 mol/L.The RSD of MPTS-ZnS QDs: Mn@MIPs to phenol test is 1.9% to 3.8%,which can be applied to the detection of phenol in actual water samples.To sum up,this paper adopted different polymerization methods,(sol-gel,gradual precipitation polymerization and atom transfer radical polymerization),to synthesize MIPs on the surface of MPTS-ZnS QDs: Mn,which act as luminophore,so as to realize effective recognition and detection for phenol,which provides a new method to effectively detect the phenols in complex water pollutants.