Lijun Zhu

Bio: Lijun Zhu is an academic researcher. The author has contributed to research in topics: Molecularly imprinted polymer & Detection limit. The author has an hindex of 3, co-authored 5 publications receiving 73 citations.

Addition of porphyrins to cigarette filters to reduce the levels of benzo[a]pyrene (B[a]P) and tobacco-specific N-nitrosamines (TSNAs) in mainstream cigarette smoke.

Abstract: Tobacco-specific N-nitrosamines (TSNAs) and benzo[a]pyrene (B[a]P) in mainstream cigarette smoke (MSS) cause smoking-related diseases and environmental pollution. Porphyrins were added to cigarette...

Cigarette filter tip additive capable of reducing smoke harmful effect to respiratory system

Abstract: The present invention relates to a cigarette filter tip additive: It is characterized by that the raw material for preparing said additive is one kind or several kinds of 15 Chinese medicinal materials of red azalea leaf, biota leaf, loquat leaf, hemp-leaved vitex seed and lonicera flower, etc. and its effective component is fraction of medium boiling range, and is obtained from extract of raw material or volatile oil of said raw material. After the additive is diluted by using 95% ethyl alcohol, the diluted solution can be added into the cigarette filter tip. Said additive has the functions of relieving cough and asthma, reducing phlegm, relieving inflammation and relieving harmful effect of smoke to respiratory system.

Gingko biloba extract and cobalt porphyrin additive to remove harmful components from cigarette smoke and reduce its toxicity

Abstract: Cigarette filters were modified with a combination of gingko biloba extract and cobalt porphyrin (CGC) to remove harmful components from the cigarette smoke and reduce its toxicity. Smoke analysis results indicated that CGC eliminated up to 32% of benzo[a]pyrene (B[a]P), 52% of N-nitrosonornicotine (NNN), 46% of N-nitrosoanabasine (NAB), 35% of 4-(methylnitrosamine)-1-(3-pyridyl)-1-butanone (NNK), 31% of N-nitrosoanatabine (NAT), 30% of gas-phase free radicals, and 33% of solid-phase free radicals. Biological experiments, including the Ames test, neutral red cytotoxicity assay and chronic toxicity, were conducted for both CGC cigarettes and control cigarettes. Results showed that the toxicity of the CGC cigarettes was lower than those of the control cigarettes. The mechanism by which the CGC components could remove harmful components from cigarette smoke is discussed.

Strategies of molecular imprinting-based solid-phase extraction prior to chromatographic analysis

Abstract: Molecular imprinting-based solid-phase extraction (MI-SPE) has been in the spotlight to improve the recognition selectivity and detection sensitivity. MI-SPE provides a powerful tool for chemo/bioanalysis in complex matrices and meanwhile, benefits from distinguished advantages such as easy operation, high throughput, low cost, high selectivity and durability. This review proposed the recent advances in molecular imprinting concerning novel preparation strategies of molecularly imprinted polymers (MIPs) and typical applications of MI-SPE. Preparation strategies are highlighted by dividing into ten sections mainly including dummy imprinting, multi-template imprinting, surface imprinting, water-compatible imprinting, restricted access material combining imprinting etc.; each section provides the descriptions about what restrictions led to the emergence of any strategy, strengths/weaknesses of every strategy and universal applications of upgraded MIPs in various SPE modes prior to chromatographic analysis. The potential of MIPs for implementation in routine laboratory activities and scale-up is expected, and finally remaining challenges and future perspectives are proposed.

Simple and selective detection of quercetin in extracts of plants and food samples by dispersive-micro-solid phase extraction based on core–shell magnetic molecularly imprinted polymers

Abstract: The objective of this study was to develop a simple, sensitive and selective procedure for the preconcentration and determination of quercetin residues in Apium graveolens, Brassica oleracea, Spinacia oleracea, watercress, onion, and apple matrices This novel method was developed on the basis of the dispersive-micro-solid phase extraction (D-μ-SPE) procedure based on a core–shell magnetic molecularly imprinted polymer (MMIP) in combination with high-performance liquid chromatography-ultraviolet (HPLC-UV) Variables affecting the quercetin extraction efficiency included pH, MIP dose, extraction contact time, elution organic solvent, and volume of organic solvent and were evaluated by the experimental central composite design (CCD) The obtained optimal parameters were as follows: pH (35), sorbent (12 mg), elution organic solvent and solvent volume (methanol, 02 mL), and elution time (220 min, without adding salt) The calibration curve was linear in the concentration range of 06–5500 μg L−1 with the lower limits of detection found in the range of 0113–0117 μg L−1, thereby revealing the high-sensitivity and -selectivity properties The combination of D-μ-SPE and HPLC-UV could provide a method for the recovery of the analyte in various matrices at 22 min contact time with good reusability and excellent recoveries at four concentration levels (50, 100, 500, and 1000 μg L−1), ranging between 9544 and 10689% (relative standard deviation <60%) Based on competitive sorption experiments, the synthesized MMIP displays higher selectivity toward quercetin compared to non-imprinted polymers (NIPs) and other sorbents

Molecularly Imprinted Materials for Selective Biological Recognition.

Abstract: Molecular imprinting is an approach of generating imprinting cavities in polymer structures that are compatible with the target molecules. The cavities have memory for shape and chemical recognition, similar to the recognition mechanism of antigen-antibody in organisms. Their structures are also called biomimetic receptors or synthetic receptors. Owing to the excellent selectivity and unique structural predictability of molecularly imprinted materials (MIMs), practical MIMs have become a rapidly evolving research area providing key factors for understanding separation, recognition, and regenerative properties toward biological small molecules to biomacromolecules, even cell and microorganism. In this review, the characteristics, morphologies, and applicability of currently popular carrier materials for molecular imprinting, especially the fundamental role of hydrogels, porous materials, hierarchical nanoparticles, and 2D materials in the separation and recognition of biological templates are discussed. Moreover, through a series of case studies, emphasis is given on introducing imprinting strategies for biological templates with different molecular scales. In particular, the differences and connections between small molecular imprinting (bulk imprinting, "dummy" template imprinting, etc.), large molecular imprinting (surface imprinting, interfacial imprinting, etc.), and cell imprinting strategies are demonstrated in detail. Finally, future research directions are provided.