Design Research On A Novel Naked-eye Colorimetric Carbon Nanosensor Based On Interfacial Reaction

With the development of economy and the advancement of industry,the problem of environmental pollution is becoming more and more serious.Especially,the heavy metal ions pollutants.Meanwhile,the human health has been threatened by the toxic cationic pollutants.So,the efficient and simple identification of cationic pollutants has become one of the most extensive research directions in nanoscience.Similarly,the designed metal-based enzyme compounded catalyst for the identification of cationic pollutants is a hot topic.A series of naked-eye colorimetric detection of heavy metal ions,which distinguishing feature is simpleness,rapidly,selectivity,sensitivity,stability and smart,have been designed.Meanwhile,these analytical means were used for monitoring environmental toxic cationic pollutants and diagnosing early markers of disease.Fitstly,we have designed a general strategy for rapid,highly selective,and ultratrace naked-eye colorimetric detection of methylmercury?CH₃Hg⁺?in aqueous solutions.In this part of the experiment,2D Pd/PEI/GO nanohybrids were synthesized and used as mimetic peroxidase for selective and ultrasensitive detection of CH₃Hg⁺.In the presence of CH₃Hg⁺,the peroxidase mimetic activity of Pd/PEI/GO nanohybrids was found to be stimulated and enhanced significantly,which promoted the effective oxidation and color change of 3,3?,5,5?-tetramethylbenzidine?TMB?in solution from colorless to blue that was detected of CH₃Hg⁺by the naked-eye method in water and human serum samples.Secondly,we have designed an effective metal-ion-controlled engineering mechanism that can control peroxidase mimetic catalytic reactions and be used for colorimetric detection of Cu²⁺by naked-eyes.The analysis method is benefited from green,simple,speedy,selective,sensitive,stable and smart detection modality.The good mimic peroxidase activity comes from the situ construction of the terminal Cu?II?-N structure of L-phenylalaninamide?LPN?functionalized carbon quantum dots?LCQDs?to form Cu?II?-LCQDs.In this work,Cu?II?-LPN units grafted on the surface of CQDs and the resulted Cu?II?-LCQDs lead to the range of electron delocalization increases,the peroxidase mimetic activity and stability are markedly enhanced comprehensively,and the good thermal and chemical stability of carbonaceous architectures can meet the demand of in-situ detection for environment and food safety.Thirdly,a novel strategy was presented and involved coupling Cu?II?complex with binding polymerization processes between N-doped carbon quantum dots?NCQDs?and L-phenylalaninamide?LPN?molecule to form Cu?II?-LPQDs carbonaceous nanoplatform architectures.It shows ultrasensitive-bidirectional characteristic in signal amplification toward monitoring of hydrogen peroxide?H₂O₂?.Ascribed to the Cu?II?-N coordination units onto the surface of the NCQDs,the mimetic peroxidase catalytic activity and stability of nanoplatform is markedly enhanced and obviously better than other types mimetic-peroxidase along with increased electron delocalization process.Our findings present some clues for making green nanoplatform in forming metalloenzyme without noble metal elements in sensing signal toward systematic catalytic mechanisms,and cooper based metalloenzyme showed highest peroxidase mimetic activity comparison with other transition metals.