Rapid Detection of Kaempferol Using Surface Molecularly Imprinted Mesoporous Molecular Sieves Embedded with Carbon Dots.

Junping Wang,Yu He,Shuo Wang

doi:10.1155/2020/5819062

Abstract

This work demonstrates rapid sensing of kaempferol using active sensing material synthesized using the one-pot surface-imprinting synthesis method. This sensor consisted of molecularly imprinted polymer (MIP) consisting of mesoporous molecular sieves (SBA-15) loaded with carbon dots (CDs). Fourier transform infrared (FT-IR) spectroscopy confirmed successful incorporation of CDs onto the surface of imprinted mesoporous molecular sieves. Ordered hexagonal arrays of CDs@SBA-15@MIP mesopore structure were confirmed with transmission electron microscopy. Fluorescence intensity of CDs@SBA-15@MIP composites linearly correlated with kaempferol content in the 0.05–2 mg/L range. Detection limit was 14 μg/L. MIPs were used for efficient detection of kaempferol in fruit and vegetable samples with recovery values from 80% to 112%. The method has high sensitivity, low cost, good selectivity, and many application potentials useful for research and development of flavonoid monomer presence in food.

Highlights

Kaempferol, a polyphenolic antioxidant present in vegetables and fruits, is a very beneficial dietary component because it is able to reduce risk of cancer and various chronic illnesses [1]
We created molecularly imprinted polymer (MIP) based on mesoporous molecular sieve (SBA-15), which was loaded with carbon dots (CDs)
Synthesis of CDs@SBA-15@MIPs and CDs@SBA-15@ NIPs. 0.28 mmol kaempferol and 1.55 mmol AM were dispersed in 25 ml of tetrahydrofuran/ethanol mixture (2.5 : 1 volume ratio) under constant stirring for 4 h at room temperature. e resulting suspension was named “mixture A.” 5.7 mmol of ethylene glycol dimethacrylate (EGDMA), acting as a cross linker, 70 mg of AIBN initiator, and 0.1 g of SBA-15-MPS were dispersed in 25 mL of tetrahydrofuran/ethanol mixture. is suspension was named “mixture B.”

Summary

Introduction

Kaempferol, a polyphenolic antioxidant present in vegetables and fruits, is a very beneficial dietary component because it is able to reduce risk of cancer and various chronic illnesses [1]. A technique to and selectively detect kaempferol in food sample as well as to distinguish kaempferol from other flavonoids is urgently needed to screen and describe food nutritional contents. Two materials, used in this work to develop such technique, are mesoporous molecular sieves and carbon dots (CDs). We created MIP based on mesoporous molecular sieve (SBA-15), which was loaded with CDs. Our main aim was to create a sensor capable to detect kaempferol accurately as well as with high sensitivity and selectively (Scheme 1). Fluorescencebased detection of kaempferol using CDs@SBA-15@MIPs as active sensing material demonstrates novel strategy for selective and sensitive kaempferol analysis in vegetable and fruits without need of bulky and expensive equipment such as liquid chromatography and mass spectrometry

Materials and Methods

Results and Discussion

Conclusions