scholarly journals Luminescent Molecularly Imprinted Polymers Based on Covalent Organic Frameworks and Quantum Dots with Strong Optical Response to Quinoxaline-2-Carboxylicacid

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 708 ◽  
Author(s):  
Zhang ◽  
Zhang ◽  
Liu
Keyword(s):  
Quantum Dots ◽  
Molecularly Imprinted Polymers ◽  
Environmental Control ◽  
Three Dimensional ◽  
Covalent Organic Frameworks ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Covalent Interaction ◽  
Highly Sensitive ◽  
Chemical Selectivity

Three-dimensional molecularly imprinted polymers (MIPs) based on quantum dots-grafted covalent organic frameworks (QDs-grafted COFs) are reported in this study. The compound 1,3,5-triformylphloroglucinol-P-phenylenediamine was used as COF material to react with the amino-modified CdSe/ZnS QDs by Schiff-base reactions. The amino-derived QDs reacted with quinoxaline-2-carboxylicacid (QCA) via a non-covalent interaction. The system combines the advantages of MIPs, COFs, and QDs for highly sensitive and selective QCA detection. The MIPs based on QDs-grafted COFs showed good chemical selectivity and thermal stability, as well as consistency in QCA optosensing. Under optimal conditions, the detection limit for QCA in meat and feed samples was 0.85 μmol L−1, over a linear concentration range of 1–50 μmol L−1. The current findings suggest a potential application of MIPs based on QDs-grafted COFs for the detection of trace levels of hazardous chemicals for food safety and environmental control.

scholarly journals Fluorescent Nanosensor based on Molecularly Imprinted Polymers Coated on Graphene Quantum Dots for Fast Detection of Antibiotics

2018 ◽  
Author(s):  
Tongchang Zhou ◽  
Arnab Halder ◽  
Yi Sun
Keyword(s):  
Quantum Dots ◽  
Fluorescence Intensity ◽  
Molecularly Imprinted Polymers ◽  
Limit Of Detection ◽  
Sol Gel ◽  
Graphene Quantum Dots ◽  
Carboxyl Groups ◽  
One Pot ◽  
Molecularly Imprinted ◽  
Imprinted Polymers

In this work, we firstly explored a mild, clean, and highly efficient approach for the synthesis of graphene quantum dots (GQDs). GQDs with carboxyl groups or amino groups, were prepared from one-pot environmentally friendly method assisted by hydrogen peroxide, respectively. It was proved that carboxyl groups played an important role in the fluorescence quenching. Based on these findings, we developed a novel fluorescent nanosensor by combining molecularly imprinted polymers (MIPs) with carboxyl functionalized GQDs for the determination of tetracycline (TC) in aqueous samples. The nanocomposite was prepared using a sol-gel process. GQDs-MIPs showed strong fluorescent emission at 410 nm when excited at 360 nm, which was subsequently quenched in the presence of TC. Under optimum conditions, the fluorescence intensity of GQDs-MIPs decreased in response to the increase of TC concentration with good linearity rage of 1.0-104 µg L-1. The limit of detection was determined to be 1 µg L-1. The fluorescence intensity of GQDs-MIPs was more strongly quenched by TC compared to the corresponding non-imprinted polymers, GQDs-NIPs. With the high sensitivity, the material was also successfully worked for the detection of TC in real spiked milk samples.

scholarly journals A Novel Fluorescence and SPE Adsorption Nanomaterials of Molecularly Imprinted Polymers Based on Quantum Dot-Grafted Covalent Organic Frameworks for the High Selectivity and Sensitivity Detection of Ferulic Acid

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 305 ◽  
Author(s):  
Yu Wang ◽  
Yuzhen Wang ◽  
Huilin Liu
Keyword(s):  
Quantum Dot ◽  
Ferulic Acid ◽  
Molecularly Imprinted Polymers ◽  
Solid Phase ◽  
Synthesis Method ◽  
Hydroxyl Groups ◽  
Covalent Organic Frameworks ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Efficient Detection

A fluorescence and solid phase extraction (SPE) adsorption nanomaterials of molecularly imprinted polymers (MIPs) based on quantum dot-grafted covalent organic frameworks (QD-grafted COFs) was prepared by one-pot surface-imprinting synthesis method. Amino groups of silane reagent were at the surface of QDs to coordinate COFs efficiently by Schiff-base reactions, providing thermal and chemical stability to MIPs. It also reacted with the phenolic hydroxyl groups of ferulic acid (FA) through non-covalent interactions. The nanomaterials were used as fluorescence sensing and SPE adsorption toward determination of ferulic acid. The MIPs based on QD-grafted COFs had good fluorescence response ability, and quenching linearly at concentrations of ferulic acid from 0.03 to 60 mg kg−1, with a detection limit of 5 µg kg−1. At the same time, it exhibited a good SPE adsorption ability, and the FA extraction was from 1.63 to 3.11 mg kg−1 in grain by-products by SPE coupled with high performance liquid chromatography/mass spectrometry (HPLC/MS). The fluorescence and SPE-HPLC/MS were used for the efficient detection of ferulic acid in real samples with recovery values of 88–114% and 90–97%, respectively. Furthermore, the nanomaterials of MIPs based on QD-grafted COFs were used for FA detection with high sensitivity and selectivity, and it also increased the recycling of waste resources.

Sign in / Sign up

Export Citation Format

Share Document