“双一流”背景下地方高校国家级化学实验教学示范中心的建设与实践

“双一流”背景下,福州大学化学实验教学中心步入了内涵式发展阶段。实验中心贯彻学校的“价值引领、知识拓展、思维训练、能力建构”四位一体育人理念,结合学校“理工结合、基础研究与应用研究相结合”的办学特色,响应学院对化学理科拔尖2.0培养计划以及各专业的新工科、新医科等发展需求,探索地方高校国家级化学实验教学示范中心建设和改革举措和方法。本文将从实验平台建设,实验教学改革,实验师资队伍建设和科普服务等方面介绍过去五年以来福州大学化学实验中心“双一流”建设的经验,突出实践作用,强化实践育人功能,切实提高实验教学内涵。

MALDI coupled with laser-postionization and trapped ion mobility spectrometry contribute to the enhanced detection of lipids in cancer cell spheroids

Cancer cell spheroids(CCS) are a valuable three-dimensional cell model in cancer studies because they could replicate numerous characteristics of solid tumors. Increasing researches have used matrix-assisted laser desorption/ionization mass spectrometry imaging(MALDI-MSI) to investigate the spatial distribution of endogenous compounds(e.g., lipids) in CCS. However, only limited lipid species can be detected owing to a low ion yield by using MALDI. Besides, it is still challenging to fully characterize the structural diversity of lipids due to the existence of isomeric/isobaric species. Here, we carried out the initial application of MALDI coupled with laser-postionization(MALDI-2) and trapped ion mobility spectrometry(TIMS) imaging in HCT116 colon CCS to address these challenges. We demonstrated that MALDI-2 is capable of detecting more number and classes of lipids in HCT116 colon CCS with higher signal intensities than MALDI. TIMS could successfully separate numerous isobaric/isomeric species of lipids in CCS. Interestingly, we found that some isomeric/isobaric species have totally different spatial distributions in colon CCS. Further MS/MS imaging analysis was employed to determine the compositions of fatty acid chains for isomeric species by examining disparities in signal intensities and spatial distributions of product ions. This work stresses the robust ability of TIMS and MALDI-2 imaging in analyzing endogenous lipids in CCS, which could potentially become powerful tools for future cancer studies.

Predesigned covalent organic framework with sulfur coordination: Anchoring Au nanoparticles for sensitive colorimetric detection of Hg(Ⅱ)

Targeted construction of new covalent organic frameworks(COFs)with specific purposes and rationalities to build colorimetric assay platform for environmental pollutant monitoring have attracted increasing interest.However,it is still challenging due to lack of available coordination sites inside COFs pores and only a slight bonding ability for anchoring metal.In this work,a two-dimensional(2D)COFs(termed as Tz-COF)with high crystallinity,excellent chemical stability,and abundant sulfur coordination in its skeletons was synthesized and used for the confined growth of Au NPs.It was found that the Au NPs showed significant dispersibility for the support of Tz-COF.The proposed Tz-COF@Au NPs possessed outstanding Hg^(2+)-activated peroxidase-like activity benefited from physicochemical properties of gold amalgam and synergistic effect between COFs and Au NPs to oxidize chromogenic substrate.Based on highly efficient activity and distinctive color evolution,the strategy for detecting Hg^(2+)was developed and successfully applied to determine the content of Hg^(2+)in real environmental samples.This work manifests that a potential strategy to establish a colorimetric assay platform for environmental pollutant monitoring based on the targeted manufacturing of novel COFs with specific functions.

Utilization of hydralazine as a reactive matrix for enhanced detection and on-MALDI-target derivatization of saccharides

Saccharides are a sort of ubiquitous and vital molecules within the whole life.However,the application of saccharides analysis with matrix-assisted laser desorption/ionization mass spectrometry(MALDI-MS)is restricted by their low ionization efficiency and the instability of the sialic acid fraction.Derivatization strategy based on nonreductive amination provides a good solution,however,this is often time consuming and may result in sample loss due to removal of excessive derivatization reagents.Herein,hydralazine(HZN)was utilized as a reactive matrix for labeling reducing saccharides directly on MALDI target which eliminated tedious sample preparation and avoided sample loss.After optimization,effective and reproducible on-MALDI-target derivatization of neutral and acidic saccharides was achieved in both positive and negative modes.Compared with 2,5-dihydroxybenzoic acid(DHB)and 9-aminoacridine(9-AA),HZN improved the detection sensitivity of reducing saccharides and provided more abundant fragment ions in MS/MS analysis.Moreover,26 kinds of neutral glycans and 5 kinds of sialic glycans were identified from ovalbumin(OVA)and bovine fetuin,respectively.Combined with the statistical models,this strategy could be used to distinguish and predict samples of 6 brands of beer,and discriminate 2 kinds of beer fermentation modes.In addition,HZN was applied for quantitative analysis of glucose in urine samples,and the obtained urine glucose concentrations of diabetic patients were consistent with the clinical test results,showing the potential of qualitative and quantitative analysis of reducing saccharides in complex samples.

Thiophene-based covalent organic frameworks for highly efficient iodine capture

Development of adsorbent materials for highly efficient iodine capture is high demand from the perspective of ecological environment and human health. Herein, the two kinds of thiophene-based covalent organic frameworks(COFs) with different morphologies were synthesized by solvothermal reaction using thieno[3,2-b]thiophene-2,5-dicarbaldehyde(TT) as the aldehyde monomer and tri(4-aminophenyl)benzene(PB) or tris(4-aminophenyl)amine(PA) as the amino monomer(denoted as PB-TT COF and PA-TT COF) and the as-prepared two heteroatoms-rich COFs possessed many excellent properties,including high thermal stability and abundant binding sites. Among them, PB-TT COF exhibited ultra-high iodine uptake up to 5.97 g/g in vapor, surpassing most of adsorbents previously reported, which was ascribed to its high specific surface(1305.3 m2/g). Interestingly, PA-TT COF with low specific surface(48.6m2/g) showed good adsorption ability for iodine in cyclohexane solution with uptake value of 750 mg/g,which was 2.38 times higher than that obtained with PB-TT COF due to its unique sheet-like morphology.Besides, the two COFs possessed good reusability, high selectivity and iodine retention ability. Based on experimental results, the adsorption mechanisms of both COFs were studied, revealing that iodine was captured by the physical-chemical adsorption. Furthermore, the both COFs showed excellent adsorption ability in real radioactive seawater treated safely, demonstrating their great potential in real environment.

Metal-organic framework nanofilm enhances serum metabolic profiles for diagnosis and subtype of cardiovascular disease

Cardiovascular disease(CVD)is a global health problem and is thought to be responsible for almost half of all deaths in the world.Nevertheless,currently available diagnostic methods for CVD are strongly depended on clinical observation and monitoring,which commonly result in false diagnosis.Herein,an attractive strategy of a metal-organic framework(MOF)nanofilm-based laser desorption/ionization mass spectrometry(LDI-MS)was developed for enhancing serum metabolic profiling,which could provide precise diagnosis and molecular subtyping of CVD.The porous MOF nanofilm fabricated on indium-tin oxide(ITO)glass possessed enhanced ionization efficiency and size-exclusion effect,which endowed it as substrate with high sensitivity and selectivity for serum metabolites.Furthermore,the MOF nanofilm with uniform surface and high orientation provided high-quality and high-reproducibility serum metabolic profiles(SMPs)without any tedious pretreatment.Further analysis of extracted serum metabolic fingerprints could successfully distinguish patients with CVD from healthy controls and also differentiate two major subtypes of CVD.This work not only extends the application of MOF nanofilm as an attractive MS probe,but also provide an alternative way for precise diagnosis of CVD in molecular level.

Polydopamine-mediated immobilization of phenylboronic acid on magnetic microspheres for selective enrichment of glycoproteins and glycopeptides

In this work, we demonstrate for the first time, a method to synthesize phenylboronic acid-Fe304@polydopamine （Fe3O4@ PDA-PBA） magnetic microspheres via the combination of mussel-inspired polydopamine coating and click chemistry. Uniform-size and core-shell structured Fe3O4@PDA-PBA magnetic microspheres with a core diameter of -240 nm and a shell thickness of -13 nm were obtained as identified by the characterization of the morphology, structure and composition of the synthesized microspheres. We evaluated the selectivity and binding capacity of the Fe3O4@PDA-PBA magnetic microsphcres by using standard glycoproteins （ovalbumin, immunoglobulin G and catalase） and nonglycoproteins （human serum albumin, bovine hemoglobin, myoglobin, lysozyme, and ribonuclease A） as model proteins. Adsorption experiments, SDS-PAGE and mass spectrometry analysis demonstrated that the Fe3O4@PDA-PBA magnetic microspheres had much high binding capacity and selectivity for glycoproteins/glycopeptides compared to nonglycoproteins/nonglycopeptides. In addition, the practicability of the Fe3O4@PDA-PBA magnetic microspheres was further assessed by selective capture of glycoproteins from healthy hu- man serum. The good results demonstrated its potential in glycoproteome analysis.

Copper(Ⅱ) ions-immobilized virus-like hollow covalent organic frameworks for highly efficient capture and sensitive analysis of amyloid beta-peptide 1–42 by MALDI-MS

Amyloid beta-peptide 1-42(Aβ1-42)is one of the biomarkers of Alzheimer's disease,and its selective capture and quantitative detection are important for diagnosis and treatment of Alzheimer's disease.Herein,copper(Ⅱ)ions-immobilized virus-like hollow covalent organic frameworks(V-HCOFs@Cu^(2+))were synthesized by a facile approach.The as-prepared V-HCOFs@Cu^(2+)showed unique morphology,ultra-high specific surface(2552 m^(2)/g),uniform mesoporous structure(3.2 nm),superior chemical stability and abundant binding sites.Based on these excellent properties,the V-HCOFs@Cu^(2+)could be adopted as an ideal enrichment probe for highly efficient capture of Aβ1-42,exhibiting high adsorption capacity(320 mg/g),and fast adsorption equilibration time(3 min).In addition,an attractive approach of the V-HCOFs@Cu^(2+)-based matrix-assisted laser desorption/ionization mass spectrometry(MALDI-MS)was developed for the rapid screening and quantitative analysis of Aβ1-42 in human serum by using C-peptide as an internal standard,which exhibited low limit of detection(LOD,0.2 fmol/μL),and satisfactory recovery.This work provides an alternative solution for enrichment of biomarkers and also offers the potential applications of COFs in clinical analysis.