Fabrication of magnetic molecularly imprinted polymer-based covalent–noncovalent synergistic imprinting strategies for the highly specific enrichment of luteolin from honeysuckle

IntroductionLuteolin (LTL) is the primary active ingredient in honeysuckle, which exhibited wide pharmacological activities, including heat-clearing, detoxifying, anti-inflammatory and anti-oxidant effects. The conventional method for the extraction of LTL consumed a substantial amount of time and organic solvents, and poor selectivity. Therefore, fabrication of novel material with simple preparation process, low cost and excellent selectivity is of great significance for the extraction and enrichment of LTL from honeysuckle.ResultsIn this system, a novel surface imprinting polymer for luteolin, denoted as Fe3O4@SiO2@MIP, was synthesized using covalent-noncovalent synergistic imprinting strategies. 3-acrylamidephenylboric acid was adopted as covalent functional monomer, deep eutectic solvent (choline chloride/methacrylic acid (ChCl/MAA, 1/2, n/n)) and methacrylic acid as the non-covalent functional monomers, and Fe3O4@SiO2 nanoparticles as the magnetic support. The resultant Fe3O4@SiO2@MIP displayed a uniform morphology, good crystallinity, and excellent magnetic properties. Meanwhile, the binding experiments demonstrated that Fe3O4@SiO2@MIP exhibited high binding performance and the maximum adsorption capacity was 20.97 mg/g. Moreover, the selectivity and reusability behavior of them were satisfactory. In addition, this polymer, serving as an adsorbent, presented practical application potential in separation and enrichment of LTL from honeysuckle.ConclusionThe covalent-noncovalent synergistic imprinting strategy could greatly facilitate the preparation of imprinted nanoparticles for the specific recognition of LTL, providing a valuable approach for the enrichment of LTL in complex samples

A Simple and Universal Nucleic Acid Assay Platform Based on Personal Glucose Meter Using SARS-CoV-2 N Gene as the Model

A simple, selective, and quantitative platform for point-of-care diagnostic of COVID-19 is urgently needed as a complement in areas where resources are currently relatively scarce. To meet the needs of early diagnosis and intervention, a proof-of-concept demonstration of a universal personal glucose meter-based nucleic acid assay platform (PGM-NAAP) is presented, which converts to SARS-CoV-2 detection from glucose detection. By using magnetic bead separation together with the hand-held PGM for quantitative readout, PGM-NAAP achieves the 98 pM limit of detection for a sequence related to SARS-CoV-2. The ability to discriminate target nucleic acid from genomic DNA, the satisfactory spike recoveries of saliva and serum samples, as well as the good stability all together suggest the potential of the PGM-NAAP for the screening and diagnosis of suspected patients during the outbreaks of COVID-19 in resource-limited settings without sophisticated instruments. On the basis of these findings, PGM-NAAP can be expected to provide an accurate and convenient path for diagnosis of disease-associated nucleic acid

Determination and calculation for solubility of m-nitroaniline and its mixture in supercritical carbon dioxide

Equilibrium solubility of m-nitroaniline and p-nitroaniline in supercritical carbon dioxide (SCCO2) is essential to design the process of SCCO2 extraction and to investigate the effect of each solute on the solubility in SCCO2 ternary system. However, the solubility data is not reported so far. We performed the solubility measurements at the temperatures of 308–328 K and in the pressure range of 11.0–21.0 MPa. The experimental results showed the solubility of m-nitroaniline and p-nitroaniline was enhanced in m-nitroaniline + p-nitroaniline + SCCO2 ternary system. The improvement factor (i), separation factor (μ) and separation efficiency (HE) in the ternary system were defined and calculated, and the best separation result could be obtained at 21.0 MPa and 328 K using SCCO2 extraction, where the separation efficiency was up to 90.9%. Based on the chemical association theory, a new model was developed to calculate the solubility of mixed solutes in SCCO2. The correlation result of the new model was tested by about 500 solubility data from 15 kinds of two solutes mixtures in SCCO2. The correlated result showed that the new model could achieve much better AARD (%) than those of frequently used Sovova and Sovova-T models