Synthesis Of Cadmium Quantum Dot Molecularly Imprinted Polymer And Its Application In Drug Analysis

Quantum dots?QDs?are semiconductor nanocrystals composed of III-V and II-VI elements.They have excellent optical properties and have a sensitizing effect on some weak chemiluminescence?CL?systems.In recent years,the study on QDs-based CL has gradually started and rapidly developed.However,analytical application of QDs-based CL has been greatly limited due to the defect of its poor selectivity and the complexity of real samples.Molecularly imprinted polymers?MIPs?have specific recognition of template molecules and good mechanical properties,so they are very suitable to be introduced into QDs-based CL systems as high-selective materials.In this way,only the target molecule can be combined with QDs,thereby eliminating the effects of other analogs on the CL signal,and further improving the selectivity and sensitivity.In this paper,cadmium-based QDs-MIPs composite nanomaterials were synthesized on the surface of QDs with QDs as the core;On basis of this,luminol-KIO₄CL systems sensitized by as-prepared QDs-MIPs were established and applied for the determination of several analgesics and antibiotics in pharmaceutical preparations coupled with flow-injection technique?FI?.In addition,the selective recognition capabilities of as-prepared QDs-MIPs nanomaterials were investigated and the possible CL mechanisms were discussed as well.The present work provides a certain experimental evidence for the analytical application of QDs-based CL methods,but also provide new promising strategies for the accurate and rapid detection of pharmaceuticals and other complex samples.This paper consists of four parts:1 IntroductionFirstly,A brief overview of the properties,synthesis methods and application of QDs in luminescence anaysis are given.Secondly,the production principle,preparation methods and application of molecular imprinting polymers are introduced.Finally,the research progress of QDs-based molecular imprinting technology is summarized.The aims and significance of the present work are also stated.2 Synthesis and application of molecularly imprinted polymer-capped CdTe@SiO₂QDs for acetaminophenMolecular imprinting polymer-capped CdTe quantum dots?CdTe@MIPs QDs?were successfully synthesized on the surface of silanized CdTe QDs with acetaminophen as template molecules.The sensitizing effect of the prepared materials on the alkaline Luminol-KIO₄ CL system was investigated.Then,a FI-CL method was developed for the fast determination of acetaminophen on basis of its quenching effect on the CdTe@MIPs QDs-Luminol-KIO₄ CL system.Under the optimal conditions,it was found that there was a good linear relationship between the logarithm value of relative CL intensity and the logarithm value of the acetaminophen concentration.The linear range was 0.010?1.2?mol/L with the detection limit of 3.7×10^-3?mol/L?3??.The relative standard deviation?RSD?was 2.37%?n=11?.The proposed method has been successfully applied to determine acetaminophen in acetaminophen tablets with the recoveries between 96.0%and 106.0%.The structural analogs of acetaminophen were used for selectivity experiments,and the results showed that CdTe@MIPs QDs have high selectivity for acetaminophen.The possible CL mechanism was briefly discussed as well.3 Synthesis and application of molecularly imprinted polymer-capped CdSe@SiO₂QDs for phenacetinMolecular imprinting polymer-capped CdSe quantum dots?CdSe@MIPs QDs?were successfully synthesized on the surface of silanized CdSe QDs with phenacetin as template molecules.a FI-CL method was developed for the fast determination of phenacetin on basis of its quenching effect on the CdSe@MIPs QDs-Luminol-KIO₄ CL system.Under the optimal conditions,it was found that there was a good linear relationship between the logarithm value of relative CL intensity and the logarithm value of the phenacetin concentration.The linear range was 0.010?3.0?mol/L with the detection limit of 2.6×10^-3?mol/L?3??.The relative standard deviation?RSD?was1.67%?n=11?.The proposed method has been successfully applied to determine phenacetin in pharmaceutical preparations with the recoveries between 97.0%and106.0%.The structural analogs of phenacetin were used for selectivity experiments,and the results showed that CdSe@MIPs QDs have high selectivity for phenacetin.4 Synthesis and application of molecularly imprinted polymer-capped CdTe/CdSe@SiO₂ QDs for tetracyclinesMolecular imprinting polymer-capped CdTe/CdSe quantum dots?CdTe/CdSe@MIPs QDs?were successfully synthesized on the surface of silanized CdTe/CdSe QDs with tetracyclines as template molecules.a FI-CL method was developed for the fast determination of tetracyclines on basis of its sensitizing effect on the CdTe/CdSe@MIPs QDs-Luminol-KIO₄ CL system.Under the optimal conditions,it was found that there was a good linear relationship between the logarithm value of relative CL intensity and the logarithm value of the tetracyclines concentration.The linear range was 0.010?10?mol/L with the detection limit of 3.2×10^-3?mol/L?3??.The relative standard deviation?RSD?was 1.78%?n=11?.The proposed method has been successfully applied to determine tetracyclines in pharmaceutical preparations with the recoveries between 96.0%and 103.0%.The structural analogs of tetracyclines were used for selectivity experiments,and the results showed that CdTe/CdSe@MIPs QDs have high selectivity for tetracyclines.