Au@Ag Core−Shell Nanocubes with Finely Tuned and Well-Controlled Sizes, Shell Thicknesses, and Optical Properties

Ma, Yanyun,Li, Weiyang,Cho, Eun Chul,Li, Zhiyuan,Yu, Taekyung,Zeng, Jie,Xie, Zhaoxiong,Xia, Younan American Chemical Society 2010 ACS NANO Vol.4 No.11

<P>This paper describes a facile method for generating Au@Ag core−shell nanocubes with edge lengths controllable in the range of 13.4−50 nm. The synthesis involved the use of single-crystal, spherical Au nanocrystals of 11 nm in size as the seeds in an aqueous system, with ascorbic acid serving as the reductant and cetyltrimethylammonium chloride (CTAC) as the capping agent. The thickness of the Ag shells could be finely tuned from 1.2 to 20 nm by varying the ratio of AgNO<SUB>3</SUB> precursor to Au seeds. We also investigated the growth mechanism by examining the effects of seeds (capped by CTAC or cetyltrimethylammonium bromide(CTAB)) and capping agent (CTAC <I>vs</I> CTAB) on both size and shape of the resultant core−shell nanocrystals. Our results clearly indicate that CTAC worked much better than CTAB as a capping agent in both the syntheses of Au seeds and Au@Ag core−shell nanocubes. We further studied the localized surface plasmon resonance properties of the Au@Ag nanocubes as a function of the Ag shell thickness. By comparing with the extinction spectra obtained from theoretical calculations, we derived a critical value of <I>ca.</I> 3 nm for the shell thickness at which the plasmon excitation of the Au cores would be completely screened by the Ag shells. Moreover, these Au@Ag core−shell nanocubes could be converted into Au-based hollow nanostructures containing the original Au seeds in the interiors through a galvanic replacement reaction.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2010/ancac3.2010.4.issue-11/nn102237c/production/images/medium/nn-2010-02237c_0001.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn102237c'>ACS Electronic Supporting Info</A></P>

An electrochemical immunosensor based on a graphene/multi-wall carbon nanotube composite platform for the detection of cardiovascular marker C-reactive protein

Du Jingjing,Ma Yuedong,Wang Yanyun 한국탄소학회 2024 Carbon Letters Vol.34 No.1

This paper presents an electrochemical immunosensor using a graphene/multi-walled carbon nanotube (MWCNT) composite platform for detecting the cardiovascular marker C-reactive protein (CRP). The immunosensor exhibited a linear detection range of 0.20–100 ng/mL CRP with a low limit of detection reaching 0.081 ng/mL. The composite material provided a 3D porous structure that allowed efficient antibody immobilization and minimized steric hindrance. The sensor showed high specificity, with minimal response to interfering substances. Using differential pulse voltammetry, the immunosensor demonstrated exceptional precision, rapid detection, and a direct correlation between CRP concentration and sensor response current. Overall, this work highlights the potential of the graphene/MWCNT composite platform as a robust tool for early CRP detection and cardiovascular disease risk assessment. The immunosensor provides sensitive and selective CRP quantification that could enable timely clinical intervention for at-risk individuals.

Au^I: an alternative and potentially better precursor than Au^III for the synthesis of Au nanostructures

Zeng, Jie,Ma, Yanyun,Jeong, Unyong,Xia, Younan Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.12

<P>This article provides an overview of current developments with regard to the use of Au<SUP>I</SUP> compounds as precursors in the synthesis of Au nanostructures with controlled shapes or morphologies. We begin with a brief description of the difference between Au<SUP>I</SUP> and Au<SUP>III</SUP> compounds, followed by a discussion on how the solubility and stability of a Au<SUP>I</SUP> compound can be improved by forming a coordination complex with a ligand (X). We then focus on a range of recent studies that have been directed towards the use of Au<SUP>I</SUP>-X complexes as precursors to elemental Au, in an effort to produce Au nanostructures with a variety of shapes, including icosahedral nanoparticles, truncated decahedrons, nanowires or nanorods, branched nanostructures, hybrid nanostructures, nanoboxes, nanocages, and nanoframes. In these syntheses, the Au<SUP>I</SUP>-X complexes offer a number of attractive features for generating Au nanostructures as compared to the conventional Au<SUP>III</SUP> compounds, mostly due to their differences in oxidation state and aurophilic effect. The ability to control Au<SUP>I</SUP> chemistry therefore provides a great opportunity to systematically investigate the syntheses, physical properties, and applications of Au nanostructures.</P> <P>Graphic Abstract</P><P>We provide an overview of recent developments in the synthesis of Au nanostructures using Au<SUP>I</SUP> compounds as the precursor. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b922571d'> </P>

Novel coal and siloxane based surfactants: Bola polysiloxanes modified with butynediol-ethoxylate and their properties

Pengxiao Fang,Yanyun Bai,Xiaoyuan Ma,Xiumei Tai,Wanxu Wang,Guoyong Wang 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.59 No.-

Novel polysiloxane amphiphiles obtained by introducing coal-based amphiphiles (butynediol ethoxylate) into polysiloxanes based on hydrosilylation reaction by two steps: first, synthesizing hydride terminated polysiloxane with different degree of polymerization (HTP); second, butynediol-ethoxylate was grafted on hydride terminated polysiloxane at terminals to get bola coal-based polysiloxane amphiphiles (EO-PSi-EO). In our work, EO-PSi-EO were compared together to investigate the impacts of different ratios of hydrophilic and hydrophobic groups on its properties. A conclusion was obtained from the work that EO-PSi-EO with various hydrophobic backbones have low surface tension, rich aggregate behavior, excellent wetting property and low foam.

Adsorption, aggregation and wetting behaviors of biodegradable surfactant: Perfluoropolyether quaternary ammonium salt

Jixian Shen,Yanyun Bai,Qiwen Yin,Wanxu Wang,Xiaoyuan Ma,Guoyong Wang 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.56 No.-

A novel cationicfluorinated surfactant, (PFP-AI), was synthesized via amidation and quaterisationsuccessively with perfluorinated acylfluride (PFPF) as starting material. Their structure was analyzed byFT-IR, 1H NMR and 19F NMR. The TG indicated the PFP-AI possess thermal stability with initiationdecomposition temperatures about 217 C. The physicochemical properties of PFP-AI were studiedsystematically by equilibrium surface tension, dynamic surface tension, dynamic light scattingmeasurement (DLS) and transmission electron microscopy (TEM). The results revealed the PFP-AIexhibited high surface activity (gcmc = 16.4 mN/m) and could aggregate into vesicles at the concentrationof 4.15 mmol/L. Furthermore, contact angle measurements demonstrated that PFP-AI exhibited efficientwettability on the hydrophobic surface.

Hair Growth Promoting Effects of 650 nm Red Light Stimulation on Human Hair Follicles and Study of Its Mechanisms via RNA Sequencing Transcriptome Analysis

( Kai Yang ),( Yulong Tang ),( Yanyun Ma ),( Qingmei Liu ),( Yan Huang ),( Yuting Zhang ),( Xiangguang Shi ),( Li Zhang ),( Yue Zhang ),( Ji’an Wang ),( Yifei Zhu ),( Wei Liu ),( Yimei Tan ),( Jinran 대한피부과학회 2021 Annals of Dermatology Vol.33 No.6

Background: Androgenetic alopecia (AGA) leads to thinning of scalp hair and affects 60%~70% of the adult population worldwide. Developing more effective treatments and studying its mechanism are of great significance. Previous clinical studies have revealed that hair growth is stimulated by 650-nm red light. Objective: This study aimed to explore the effect and mechanism of 650-nm red light on the treatment of AGA by using ex vivo hair follicle culture. Methods: Human hair follicles were obtained from hair transplant patients with AGA. Hair follicles were cultured in Williams E medium and treated with or without 650-nm red light. Real-time RT-PCR and immunofluorescence staining were used to detect the expression level of genes and proteins in hair follicles, respectively. RNA-sequencing analysis was carried out to reveal the distinct gene signatures upon 650 nm treatment. Results: Low-level 650 nm red light promoted the proliferation of human hair follicles in the experimental cultured-tissue model. Consistently, 650 nm red light significantly delayed the transition of hair cycle from anagen to catagen in vitro. RNA-seq analysis and gene clustering for the differentially expressed genes suggests that leukocyte transendothelial migration, metabolism, adherens junction and other biological process maybe involved in stimulation of hair follicles by 650-nm red light treatment. Conclusion: The effect of 650-nm red light on ex vivo hair follicles and the transcriptome set which implicates the role of red light in promoting hair growth and reversing of miniaturization process of AGA were identified.

Micellization and aggregation properties of sodium perfluoropolyether carboxylate in aqueous solution

Qiwen Yin,Wanxu Wang,Wei Xue,Yanyun Bai,Xiaoyuan Ma,Zhiping Du,Guoyong Wang 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.42 No.-

Sodium perfluoropolyether carboxylate (PFPE-Na) was synthesized via hydrolyzing the correspondinghexafluoropropylene oxide oligomer (PFPF). The structure of PFPE-Na was characterized by FT-IR and 19FNMR. The micellization and aggregation properties of PFPE-Na surfactant in aqueous solution werestudied systematically using equilibrium surface tension, electrical conductivity, dynamic surfacetension, steady-statefluorescence, transmission electron microscopy (TEM) and contact anglemethodologies. The results of equilibrium surface tension at 25 C showed that the critical micelleconcentration (CMC) and the surface tension at CMC (gCMC) of PFPE-Na aqueous solution are lower thansodium perfluorooctanoate [NaPFO, C7F15COONa], which revealing that as a kind of environment-friendly surfactant, PFPE-Na is a perfect substitute of NaPFO. Electrical conductivity measurementsimplied that the micellization of PFPE-Na in aqueous solution was an exothermic and entropy-drivenprocess in the range of temperature investigated. Steady-statefluorescence and transmission electronmicroscopy (TEM) may indicate that PFPE-Na self-assemble in aqueous solution to form larger sphericalaggregates with the increase of concentration. In addition, dynamic surface tension measurements ofPFPE-Na solution showed an extremely efficient adsorption at concentrations above CMC while thedetermination of contact angle of PFPE-Na showed the wetting ability was general.

Association of microRNA-3144 variant with the susceptibility to hepatocellular carcinoma

Jun Zhang,Yi Liu,Jie Liu,Rui Wang,Min Cai,Shunji Yu,Yanyun Ma,Weihong Xu,Chunfang Gao,Jiucun Wang,Lifang Hou 한국유전학회 2014 Genes & Genomics Vol.36 No.6

Increasing studies suggest that microRNAs, anew group of small non-coding molecules, regulate theexpression of their target genes and play some roles in cancers. Thus, it is hypothesized that the genetic variants ofmicroRNAs could contribute to the susceptibility to cancers. In this study, the association between rs67106263 in microRNA-3144 and the risk of hepatocellular carcinoma (HCC)was explored in a large-scaled case–control population basedon MassARRAY technology. It was discovered that comparedwith the carriers of wide-type GG genotype and heterozygoteGA genotype of microRNA-3144, thesignificantly increased risk of HCC was observed in thesubjects with the homozygote variant AA (adjusted oddsratio = 1.285, 95 % confidence interval = 1.004–1.643,P = 0.046). Additionally, the variant was also associatedwith the expression of alpha fetoprotein (AFP), which is thediagnostic marker for HCC. Our findings suggest for the firsttime that rs67106263 may play some roles in the risk of HCC,expecting future molecular researches to elucidate the possiblemechanisms behind these results.

Synthesis of Gold Nano‐hexapods with Controllable Arm Lengths and Their Tunable Optical Properties

Kim, Do Youb,Yu, Taekyung,Cho, Eun Chul,Ma, Yanyun,Park, O Ok,Xia, Younan WILEY‐VCH Verlag 2011 Angewandte Chemie Vol.123 No.28

<P><B>Ein Stern wird geboren</B>: Gold‐Hexapoden mit kontrollierten Armlängen wurden durch selektives Wachstum an den Ecken oktaedrischer Au‐Keime gebildet. Abhängig von der Armlänge, die über die HAuCl<SUB>4</SUB>‐Menge und die Reaktionstemperatur eingestellt werden kann, verschiebt sich die Oberflächenplasmonenresonanz der Nanohexapoden vom sichtbaren in den nahinfraroten Bereich (siehe Bild).</P>