Modification Of Mn:ZnS QDs And Their Application In Environmental And Biological Detection

Quantum dots(QDs)is a special new type of nanomaterials with unique advantages and functions.They are simple in synthesis,low in cost,high in selectivity,high in sensitivity,fast and convenient in detection.They have wide applications and prospects for biological,chemical detection,environmental monitoring,medical and other fields.In this paper,two kinds of Mn doped Zn S quantum dots(Mn:Zn S QDs)modified by surface ligands were prepared by aqueous synthesis method.The RTP properties of Mn:Zn S QDs were explored and the phosphorescent sensing system based on the synthesized was constructed.The main research contents are divided into the following three parts:1.The room temperature phosphorescence(RTP)method based on Thioguanine(TG)modified Mn:Zn S quantum dots(QDs)was used to detect platinum ions.The phosphorescence of QDs solution was rapidly quenched when platinum ions was added.The mechanism of reaction is inferred as platinum ions would combine with nitrogen atoms on Thioguanine to form N-Pt⁴⁺coordination structure attached to the surface of QDs,resulting in phosphorescence quenched of QDs due to electron transfer.Based on this,constructed a phosphorescent probe for detecting platinum ions.The method with a good linear relationship of phosphorescence quenched efficiency and platinum ions concentration within the range of0.6?2.0?g/m L(y=0.0884x+0.2319,R²=0.991),and the detection limit was 0.31?g/m L.This phosphorescence probe was superior with convenience and high speed,has favorable selectivity,can be used to detect platinum ions in real samples.2.The phosphorescence sensing effect of STPP-Mn:ZnS QDs on Fe³⁺and Dopamine hydrochloride was studied.Fe³⁺can effectively quenching the phosphorescence intensity of STPP-Mn:Zn S QDs.The concentration of Fe³⁺in the range of 10?100?M has a good linear relationship between the phosphorescence quenching degree of STPP-Mn:Zn S QDs,the detection limited are 2.69?M.Adding Dopamine hydrochloride can effectively enhance the phosphorescence of STPP-Mn:Zn S QDs-Fe³⁺system.In the range of 2?50?M,the detection limited are 1.85?M.The phosphorescent sensor constructed in this section can effectively complete the sensing detection of Fe³⁺and Dopamine hydrochloride in water samples.It has a wide detection range,high sensitivity and good selectivity,and has certain application value for the detection and analysis of Fe³⁺and Dopamine hydrochloride.3.The phosphorescence sensing effect of STPP-Mn:ZnS QDs on Pb²⁺and M-phenylenediamine(MPD)was explored.The phosphorescence quenching effect of Pb²⁺on STPP-Mn:Zn S QDs was detected under room temperature phosphorescence.The results show that Pb²⁺can effectively quenching the phosphorescence intensity of STPP-Mn:Zn S QDs.The linear range of Pb²⁺concentration is 5?50?M,the detection limited are 2.28?M.The addition of MPD to STPP-Mn:Zn S QDs-Pb²⁺system can effectively enhance the phosphorescence of STPP-Mn:Zn S QDs-Pb²⁺system.The good linear relationship in the concentration range of 1?30?M,and the detection limited are 0.022?M.The phosphorescent sensor constructed in this section can effectively complete the sensing detection of Pb²⁺and MPD in water samples.It has a wide detection range,low detection limit,high sensitivity and good selectivity,and has certain application value for the detection and analysis of Pb²⁺and MPD.