Zhenhua Chen

Preparation of Nickel Cobalt Sulfide Hollow Nanocolloids with Enhanced Electrochemical Property for Supercapacitors Application

Nanostructured functional materials with hollow interiors are considered to be good candidates for a variety of advanced applications. However, synthesis of uniform hollow nanocolloids with porous texture via wet chemistry method is still challenging. In this work, nickel cobalt precursors (NCP) in sub-micron sized spheres have been synthesized by a facile solvothermal method. The subsequent sulfurization process in hydrothermal system has changed the NCP to nickel cobalt sulfide (NCS) with porous texture. Importantly, the hollow interiors can be tuned through the sulfurization process by employing different dosage of sulfur source. The derived NCS products have been fabricated into supercapacitor electrodes and their electrochemical performances are measured and compared, where promising results were found for the next-generation high-performance electrochemical capacitors.

In situ mineralization of anticancer drug into calcium carbonate monodisperse nanospheres and their pH-responsive release property

In this paper, we facilitated the preparation of uniform calcium carbonate nanospheres and the encapsulation of anticancer drug (Doxorubicin, Dox) in one step by a facile bio-inspired mineralization method at room temperature. Hesperidin (Hesp), a natural originated flavanone glycoside, was introduced as crystallization modifier. The obtained Dox encapsulated CaCO3 nanospheres (Dox@CaCO3-Hesp NSs) having a narrow size range of ~200 nm. The drug loading/release studies reveal that these Dox@CaCO3-Hesp NSs have a drug loading efficiency (DLE) of 83% and drug loading content (DLC) of 14wt%. Besides, the release of Dox from Dox@CaCO3-Hesp NSs was pH depended. At pH=7.4, only a small amount (~28%) of Dox was released. While at pH=5.0, all amount of incorporated Dox was released. Confocal laser scanning microscopy (CLSM) image reveals the Dox@CaCO3-Hesp NSs can internalize the cells. These results suggest the Dox@CaCO3-Hesp NSs can be potentially used to utilize pH-responsive delivery of anticancer drugs.

Fluorescence enhancement for noble metal nanoclusters

Noble metal nanoclusters have attracted great attentions in the area of fluorescence related applications due to their special properties such as low toxicity, excellent photostability and bio-compatibility. However, they still describe disadvantages for low quantum yield compared to quantum dots and organic dyes though the brightness of the fluorescence play an important role for the efficiency of the applications. Attentions have been attracted for exploring strategies to enhance the fluorescence based on the optical fundamentals through various protocols. Some methods have already been successfully proposed for obtaining relative highly fluorescent nanoclusters, which will potentially describe advantages for the application. In this review, we summarize the approach for enhancement of the fluorescence of the nanoclusters based on the modification of the properties, improvement of the synthesis process and optimization of the environment. The limitation and directions for future development of the fabrication of highly fluorescent metal nanoclusters are demonstrated.

One-pot development of water soluble copper nanoclusters with red emission and aggregation induced fluorescence enhancement

One-pot synthesis of water-soluble Cu NCs using DHLA protection ligands by different reducing reagents including NaBH4, N2H4 and THPC was developed. Furthermore, it was found that the as prepared Cu NCs using THPC as a reducing reagent describe fluorescence enhancement in the presence of Zn2+ and Al3+. It is proposed that the binding of Zn2+ and Al3+ to OH on the copper core of Cu NCs promotes the formation of CuNC–OH–Zn–OH–Cu NCs and CuNC–OH–Al–OH–Cu NCs aggregates respectively, which enables aggregation induced fluorescence enhancement. Additionally, it was found that the fluorescence enhancement were partly reversible by the introduction of an alkaline buffer solution and Zn2+.

Green synthesis of highly fluorescent AuNCs with red emission and their special sensing behavior for Al3

Facile methods were fabricated for preparation of highly fluorescent AuNCs with red emission using L-cysteine. Water soluble and aggregation induced AuNCs have been prepared by the employment of the same ligand. The emission wavelength of the as-prepared water soluble AuNCs can be tuned by simply adjusting the amounts of the reactants. Interestingly, it is further found that the fluorescence of AuNCs which has been quenched by Pb2+ can be recovered by Al3+. This provides a new approach for ‘turn-on’ detection of Al3+ in aqueous solution. A mechanism for sensing that is related to the residual reducing reagent (THPC) has been proposed base on the investigation of various related nanoclusters-based systems.

Enhancement of fluorescence brightness and stability of copper nanoclusters using Zn2 + for ratio-metric sensing of S2 −

It is acknowledged water soluble copper nanoclusters (Cu NCs) are extremely unstable in aqueous solutions, which limit their fluorescence applications to a great extent. In this work, it is found the fluorescence intensity and stability of water soluble Cu NCs could obviously be enhanced by the introduction of Zn2+. Then, the as modified Cu NCs will be stable enough to be applied as a ratio-metric sensor for S2-. This method may provide more broaden avenues for the application of fluorescent Cu NCs in the future.

Preparation of core–shell structured CaCO 3 microspheres as rapid and recyclable adsorbent for anionic dyes

Core–shell structured CaCO3 microspheres (MSs) were prepared by a facile, one-pot method at room temperature. The adsorbent dosage and adsorption time of the obtained CaCO3 MSs were investigated. The results suggest that these CaCO3 MSs can rapidly and efficiently remove 99–100% of anionic dyes within the first 2u2009min. The obtained CaCO3 MSs have a high Brunauer–Emmett–Teller surface area (211.77u2009m2u2009g−1). In addition, the maximum adsorption capacity of the obtained CaCO3 MSs towards Congo red was 99.6u2009mgu2009g−1. We also found that the core–shell structured CaCO3 MSs have a high recycling capability for removing dyes from water. Our results demonstrate that the prepared core–shell structured CaCO3 MSs can be used as an ideal, rapid, efficient and recyclable adsorbent to remove dyes from aqueous solution.

Prepare porous silica nanospheres for water sustainability: high efficient and recyclable adsorbent for cationic organic dyes

In this paper, we prepared monodisperse porous silica nanospheres (SiO2 NSs) to adsorb organic dyes. The obtained porous SiO2 NSs have uniform size of ~xa0350xa0nm in diameter. Zeta potential result reveals the obtained porous SiO2 NSs are negative charged. The adsorption property of porous SiO2 NSs was analyzed by various influenced factors, such as adsorbent doses, adsorption time, removal efficiency, and adsorption capacity and recycle adsorption capability. In a very short adsorption time of 5xa0min, the obtained porous SiO2 NSs have efficient removal efficiency of 99.71% (for Alcian blue) and 99.06% (for methylene blue) and high adsorption capacity of 250xa0mg/g (for Alcian blue) and 160xa0mg/g (for methylene blue), higher than previously reported adsorbents. Recycle adsorption experiments (using calcination method) show that porous SiO2 NSs could be recycled at least six times while the removal efficiency had no significant decrease (<xa02%).

Preparation of anticancer micro-medicine based on quinoline and chitosan with pH responsive release performance

N-(2-(3-fluorobenzyl)-2H-indazol-5-yl)-2-phenyl-2H-pyrazolo[4,3-c]qui- nolin-4-amine (LZC-2b) with a quinoline structure was synthesized as an anticancer prodrug. The pH sensitive anticancer drugs obtained by a simple hydrothermal method. The interaction of chitosan (Cts) and LZC-2b is used to complete the encapsulation without any cross-linking. The obtained micromedicine (LZC-2b@Cts-MSs) has an average size of ∼980u202fnm. The drug loading efficiency (DLE) of LZC-2b@Cts-MSs was about 79%. In addition, drug release from LZC-2b@Cts-MSs was pH depended. At pHu202f=u202f7.4, only 5.1% of loaded LZC-2b was released, while 90.3% of loaded LZC-2b was released at pHu202f=u202f5.0. Cell culture results indicate that LZC-2b@Cts-MSs can be easily uptaken by KB cells. Cell viability results show that KB cells can be effectively killed by LZC-2b@Cts-MSs. Our strategy of synthesis and preparation of pH responsive LZC-2b@Cts-MSs has promising prospect in chemotherapy of oral cancer.

GSH and enzyme responsive nanospheres based on self-assembly of green tea polyphenols and BSA used for target cancer chemotherapy

Developing safe and effective stimuli-responsive nanocarriers is very important for tumor chemotherapy. In this work, bovine serum albumin (BSA) and green tea polyphenol (TP) were used to prepare glutathione (GSH) and enzyme (trypsin) responsive nanocarriers for doxorubicin (DOX). These nanocarriers were further modified with folate, briefly named as DOX@BSA-TP-FA NSs. The diameter of nanocarriers was about 220u2009nm. The DOX loading efficiency and loading amount were 86.4% and 23.5u2009wt%, respectively. The cellular uptake, apoptosis, and GSH and trypsin responsive release properties of these nanocarriers were investigated.