Molecularly imprinted polymers based on calcined rape pollen and deep eutectic solvents for efficient sinapic acid extraction from rapeseed meal extract

Substances that possess hierarchical and interconnected porous features are ideal choices for acting as skeletons to synthesize surface molecularly imprinted polymers (MIPs). In this work, rape pollen, a waste of biological resources, was calcined and a porous mesh material with a high specific surface area was obtained. The cellular material was adopted as a supporting skeleton to synthesize high-performance MIPs (CRPD-MIPs). The CRPD-MIPs presented an ultrathin imprinted layered structure, with an enhanced adsorption capacity for sinapic acid (154 mg g^-1) relative to the non-imprinted polymers. The CRPD-MIPs also exhibited good selectivity (IF = 3.24) and a fast kinetic adsorption equilibrium (60 min). This method exhibited a good linear relationship (R2 = 0.9918) from 0.9440 to 29.26 μg mL^-1, and the relative recoveries were 87.1-92.3%. The proposed CRPD-MIPs based on hierarchical and interconnected porous calcined rape pollen may be a valid program for the selective extraction of a particular ingredient from complicated actual samples.

Accessing p-Hydroxycinnamic Acids: Chemical Synthesis, Biomass Recovery, or Engineered Microbial Production?

p-Hydroxycinnamic acids (i. e., p-coumaric, ferulic, sinapic, and caffeic acids) are phenolic compounds involved in the biosynthesis pathway of lignin. These naturally occurring molecules not only exhibit numerous attractive properties, such as antioxidant, anti-UV, and anticancer activities, but they also have been used as building blocks for the synthesis of tailored monomers and functional additives for the food/feed, cosmetic, and plastics sectors. Despite their numerous high value-added applications, the sourcing of p-hydroxycinnamic acids is not ensured at the industrial scale except for ferulic acid, and their production cost remains too high for commodity applications. These compounds can be either chemically synthesized or extracted from lignocellulosic biomass, and recently their production through bioconversion emerged. Herein the different strategies described in the literature to produce these valuable molecules are discussed.

A fluorescent microsensor for the selective detection of bifenthrin

Based on the fluorescence quenching phenomenon, a smart fluorescent microsensor was synthesized. The bifenthrin (BI) microsensor inherited the high selectivity of molecular imprinted polymers (MIPs) and the excellent fluorescence properties of aqueous CdTe quantum dots (QDs). Aqueous CdTe QDs are functionalized by octadecyl-4-vinylbenzyl-dimethyl-ammonium chloride (OVDAC). A type of functional monomer, 4-vinylphenylboronic acid (VPBA), was used and its boronic acid groups could covalently combine with a cis-diol compound for direct imprinting polymerization. The OVDAC-functionalized aqueous CdTe QDs were used as solid supports and auxiliary monomers. Under optimal conditions, experimentation showed that BI had a linear detection range of 10 to 300 μmol L⁻¹ with a correlation coefficient of 0.9968 and a high imprinting factor (IF) of 4.53. In addition, the prepared MIP-OVDAC/CdTe QDs were successfully used to detect BI in water samples. Therefore, this work provided a highly selective and sensitive fluorescence probe for the detection of BI. In addition, the fluorescence probe could be used to detect other targets by changing the functional monomers.

Based on the fluorescence quenching phenomenon, a smart fluorescent microsensor was synthesized.