CARBOHYDRATE POLYMERS
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2022
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IF 10.723
Congwei Li,Lian Duan,Xinjian Cheng
Fluorescent chitosan-based hydrogel for the selective detection and adsorption of Hg 2+ /Hg + in aqueous environment was prepared through three-step synthesis strategy. NO 2 -Boron-dipyrrolemethene (BODIPY) was prepared firstly, and then the -NO 2 group was reduced to -NH 2 group. Finally, the NH 2 -BODIPY was introduced to chitosan by Schiff base formation reaction through bi-aldehyde. Eventually, fluorescent chitosan hydrogel was obtained. The as-prepared fluorescent hydrogel probe could detect Hg 2+ /Hg + through PET mechanism with the detection limit of 0.3 μM. The recognition site which combines Hg 2+ /Hg + is C N, it is just formed in the reaction with chitosan and the amino group on BODIPY. Adsorption capacity of the fluorescent hydrogel is 121 mg·g −1 , which is almost seven times of the original chitosan. The isotherm and kinetics of Hg 2+ /Hg + removal follows Langmuir isotherm and pseudo-second order kinetics , respectively. Besides, a series of fluorescent hydrogels were prepared to compare the elasticity, hydropHilicity , fluorescence intensity and adsorption capacity.
研究领域:
材料科学
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环境科学
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化学工程
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DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2022
·
IF 9.221
Kaiqi Liu,Luminita Marin,Xinjian Cheng
In this work, fluorescent β- cyclodextrin (β-CD) based probes containing naphthalimide group were synthesized to realize the specific recognition of Hg 2+ /Hg + in aqueous system. Firstly, three small fluorescent molecules (N1, N2 and N3) with -NH 2 groups were synthesized from 4-bromo-1, 8-naphthalene anhydride . Secondly, CH CCH 2 - group was introduced into β-CD by Williamson ether formation reaction. Finally, the target probes (β-CD-PI, β-CD-PY and β-CD-TP) were obtained by Amino-Yne click reaction. These probes can efficiently recognize Hg 2+ /Hg + . β-CD-PI emits bright yellow fluorescence after binding with Hg 2+ /Hg + , which is a turn-on fluorescent probe . When the Hg 2+ /Hg + concentration exceeds 26 μM, the fluorescence intensity amplifies sharply (20 folds). The hydrophobic parts of the probes aggregated together to form a micelle-like structure due to complexation with Hg 2+ /Hg + , resulting in special micelle-sensitizing properties. Meanwhile, the HOMO-LUMO energy levels of the probes were calculated by cyclic voltammetry (CV). The probe is expected to be used for the detection of Hg 2+ /Hg + in aqueous solutions without any organic solvents.
研究领域:
分析化学
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环境科学
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材料科学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2023
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IF 8.2
Jiao He,Lin Yun,Xinjian Cheng
Chitosan as the plentiful and easily available natural polymer, its solubility in organic solvents is still a challenge. In this article, three different chitosan-based fluorescent co-polymers were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. They could not only dissolve in several organic solvents, but also could selectively recognize Hg 2+ /Hg + ions. Firstly, allyl boron-dipyrrolemethene (bodipy) was prepared, and used as one of the monomers in the subsequent RAFT polymerization. Secondly, chitosan-based chain transfer agent (CS-RAFT) was synthesized through classical reactions for dithioester preparation. Finally, three methacrylic ester monomers and bodipy bearing monomers were polymerized and grafted as branched-chains onto chitosan respectively. By RAFT polymerization, three chitosan-based macromolecular fluorescent probes were prepared. These probes could be readily dissolved in DMF, THF, DCM , and acetone. All of them exhibited the ‘turn-on’ fluorescence with selective and sensitive detection for Hg 2+ /Hg + . Among them, chitosan-g-polyhexyl methacrylate-bodipy (CS-g-PHMA-BDP) had the best performance, its fluorescence intensity could be increased to 2.7 folds. In addition, CS-g-PHMA-BDP could be processed into films and coatings. When loading on the filter paper, fluorescent test paper was prepared and it could realize the portable detection of Hg 2+ /Hg + ions. These organic-soluble chitosan-based fluorescent probes could enlarge the applications of chitosan.
研究领域:
材料科学
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分析化学
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生物医学工程
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
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IF 15.1
Jiao He,Siyuan Zhang,Xinjian Cheng
Dendritic fiber nanosilica (DFNS) possesses a unique porous structure, and its potential application for adsorption and separation, particularly of heavy metals, should be explored. This study, to our knowledge, is the first time to introduce fluorescence recognition ability to DFNS and to combine it with polymer materials. Firstly, the fluorescent DFNS (FL-DFNS) was prepared by a Schiff base formation reaction between the naphthalamide fluorophore and the modified DFNS. Then, a two-step approach was employed to fabricate FL-DFNS/polyurethane (FL-DFNS/CSPU-02) nanocomposite materials. FL-DFNS functions as a “turn off” sensor for Hg 2+ /Hg + ions, exhibiting fluorescence quenching of up to 81.1 %/75.9 %. It also has an excellent adsorption capacity to mercury. Specifically, FL-DFNS/CSPU-02 membrane enabled portable detection of Hg 2+ /Hg + ions. Importantly, it exhibited superior performance in the adsorption and separation of Hg 2+ /Hg + ions, achieving a removal efficiency of 97.7 % and 98.0 %, with an absorption capacity of 382.4/373.5 µg/cm 2 . And it can be recycled for at least nine times. Overall, this study confirms the practical application value of FL-DFNS and FL-DFNS/CSPU-02 membrane in the recognition and removal of Hg 2+ /Hg + ions, it will achieve the real application in environmental science and engineering.
研究领域:
环境科学
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材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2023
·Vol. 141
·期 4
·e54853
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IF 3
Meng Xie,Ke Yang,Yuye Wang,Xinjian Cheng
Heavy metal (HM) pollution is getting worse with the society progress. Identification and separation of HM ions are urgent issues in environmental protection and social development. In this work, 4-bromo-1,8-naphthalic anhydride was first reacted with amino-propylene glycol to synthesize naphthimide fluorophores bearing two hydroxyl groups. And then, –Br was substituents by 8-mercaptoquinoline, 2-mercaptoimidazole, and 4-mercaptopyridine, respectively. Eventually, it was reacted with 1,5-naphthalene diisocyanate (NDI) to synthesize fluorescent polyurethane (PU) films through the reaction between –OH and –NCO. It is found that the PU film not only has a specific identification ability to Hg 2+ /Hg + and Fe 3+ ions, but also can efficiently remove Hg 2+ /Hg + and Fe 3+ ions through adsorption. In addition, selective identification by fluorescence quenching was investigated. It is due to the photoinduced electron transfer mechanism (PET). Furthermore, the lowest detection limits for Fe 3+ , Hg 2+ , and Hg + were 6.0 × 10 −7 M, 4.7 × 10 −7 M, and 9.7 × 10 −7 M, respectively, which reflected the sensitivity of the probe and made it fluorescence probes. The three fluorescent small molecules were incorporated into PU, which not only retain their identification function, but also serve the purpose of adsorption and separation of HM ions.
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高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2022
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IF 4.778
Jiao He,Congwei Li,Xinjian Cheng
Three chitosan-BODIPY probes were prepared in this work. The water solubility of original chitosan has been improved. Water soluble fluorescent probes were obtained. They also exhibited good sensing ability to Hg 2+ /Hg + ions. Firstly, through the amidation reaction, arginine, cysteine, and tryptophan were grafted respectively onto chitosan chains. And then chitosan-BODIPY probes were produced by means of Schiff base formation reaction. By this way, the high structural regularity of chitosan polymer chains was changed with introducing amino acids and fluorescent groups. It also endowed fluorescence sensing ability. They could recognize Hg 2+ /Hg + ions with the interaction of C N groups. It could selectively recognize Hg 2+ /Hg + in aqueous solution, the detection limits reached 0.747μM/0.783 μM. Moreover, by the introduction of hydrophilic groups, the contact angle of modified chitosan film was improved as well. It realized performance transformation from the hydrophobic to hydrophilic. The viscoelasticity , thermal, rheological properties and fluorescence properties of the hydrogels were investigated. C N groups not only acted as a binding site to coordinate with heavy metals, but also could enhance the water solubility of the fluorescent chitosan.
研究领域:
生物化学
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材料科学
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环境科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Jiao He,Yuxiang Huang,Jinlei Xu,Fang Zeng,Xinjian Cheng
Dendritic fibrous nano-silica (DFNS) possesses unique porous structure, making it an outstanding candidate for heavy metal adsorption and separation. It is interesting to introduce natural polymer (chitosan) into DFNS and produce natural materials-based porous DFNS. Initially, in this work, DFNS underwent modification to enlarge size and enrich with -C≡C bonds. And then, NH2-naphthalimide fluorophore was click-reacted with the modified DFNS, forming fluorescent DFNS (FL-DFNS). Eventually, chitosan was integrated into FL-DFNS using diacyl chloride, generating the organic–inorganic fluorescent composite micro-beads (FL-DFNS@CS-3). FL-DFNS acts as a “turn on” sensor for Hg 2+ /Hg + ions, showing up to 5 times fluorescence increase. Also, it exhibited effective mercury adsorption. Due to its porous structure, it demonstrated good performance in adsorbing and separating Hg 2+ /Hg + ions, achieving removal ratios of 98.8 % and 96.1 %, and adsorption capacities of 196.2 mg/g and 180.4 mg/g, respectively. It reached effective adsorption equilibrium within 15 min and was reusable up to seven times. Overall, this work confirms the practical applicability of FL-DFNS and FL-DFNS@CS micro-beads for identifying and removing Hg 2+ /Hg + ions. Further exploration is worthy to explore its potential in environmental science and engineering.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CHEMICAL PAPERS
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2022
·Vol. 76
·期 11
·7037-7049
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IF 2.146
Zhang Lin,Jiao Xinyue,Zhang Huijuan,He Suyan,Cheng Xinjian
Heavy metal ions are harmful to the environment and the human beings and other creatures. Fluorescent agents play important roles in the detection of heavy metals. Chitosan-based fluorescent probes were synthesized and investigated in this work. Firstly, 4-bromo-1,8-naphthimide was introduced into chitosan through nucleophilic addition–elimination reaction, and then the Br was replaced by amino acid through substitution reaction. By this way, three chitosan–naphthalimide–amino acid fluorescent probes were obtained consequently. The structure and fluorescence properties of macromolecular probes were characterized and confirmed. These macromolecules have good selectivity and sensitivity to Hg 2+ /Hg + , and Fe 2+ ions. When Hg + /Hg 2+ ions are present, the probe P1 produces a significant increase in fluorescence intensity. The LOD of P1 to Hg + and Hg 2+ are 1.66 × 10 −6 M and 1.60 × 10 −6 M, respectively. When Fe 2+ ions exist with the presence of P2 and P3 probes, P2 and P3 show significant fluorescence quenching, and their LODs are 1.09 × 10 −6 M and 6.65 × 10 −7 M, respectively. And these three chitosan derivatives also have good adsorption effect on ions, the maximum adsorption capacity of mercury can reach 108.7 mg/g, and the maximum adsorption capacity of ferrous iron can reach 52.0 mg/g. This mechanism of recognition and adsorption is formed as the complexation of N and ions on the probe. In this article, a material with good recognition, and removal of Hg + /Hg 2+ and Fe 2+ is developed, which also provides a way for the potential remediation of heavy metal polluted water.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 48
·22888-22901
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IF 3.591
Kaiqi Liu,Luminita Marin,Li Xiao,Xinjian Cheng
Multi-component polymers (MCPs) incorporate multiple components into the main chain or pendant group and have special functions. In this work, the small-molecule fluorescent boron-dipyrromethene (BODIPY), with ester groups and/or alkoxyl long chains, was synthesized first. Then, this small-molecule BODIPY and the components containing CC bonds (HD and PD) were reacted via the Heck coupling reaction to obtain macromolecular probes that perform different functions. With the help of ester groups and alkoxyl “tail”, polymers MCP1 and MCP2 were soluble in a variety of water-miscible organic solvents. Moreover, MCP3 and MCP4 were completely soluble in water. These macromolecular probes showed sensitive and selective recognition toward Hg2+/Hg+ because of the introduced components (HD and PD) containing CC bonds. After binding to Hg2+/Hg+, MCP1 and MCP2 demonstrated fluorescence quenching and color changes, which allowed the dual-channel specific detection of Hg2+/Hg+. Compared with the probes containing HD, the probes containing PD showed higher sensitivity, and the good recognition ability caused the detection limit to be as low as 0.32 μM, which may be due to the “molecular wire” mechanism. The small-molecule components with different functional groups were polymerized into fluorescent polymer materials. This methodology endows the polymer probe with good solubility and high sensitivity, and the as-prepared polymers could sense metal ions in aqueous environments.
研究领域:
分析化学
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材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）