Fabrication of novel compound SERS substrates composed of silver nanoparticles and porous gold nanoclusters: A study on enrichment detection of urea

Li, Yali,Li, Qianwen,Sun, Chengbin,Jin, Sila,Park, Yeonju,Zhou, Tieli,Wang, Xu,Zhao, Bing,Ruan, Weidong,Jung, Young Mee Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.427 No.2

<P><B>Abstract</B></P> <P>A new type of surface-enhanced Raman scattering (SERS) substrate was fabricated through the layer-by-layer self-assembly of silver nanoparticles (AgNPs, av. 45nm in diameter) and porous gold nanoclusters/nanoparticles (AuNPs, av. 143nm in diameter). The development of the porosity of the AuNPs was investigated, and successful SERS applications of the porous AuNPs were also examined. As compared with AgNP films, the enhancement factor of Ag-Au compound substrates is increased 6 times at the concentration of 10<SUP>−6</SUP> M. This additional enhancement contributes to the trace-amount-detection of target molecules enormously. The contribution is generated through the increase of the usable surface area arising from the nanoscale pores distributed three-dimensionally in the porous AuNPs, which enrich the adsorption sites and hot spots for the adsorption of probe molecules, making the developed nanofilms highly sensitive SERS substrates. The substrates were used for the detection of a physiological metabolite of urea molecules. The results reached to a very low concentration of 1mM and exhibited good quantitative character over the physiological concentration range (1∼20mM) under mimicking biophysical conditions. These results show that the prepared substrate has great potential in the ultrasensitive SERS-based detection and in SERS-based biosensors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new type of SERS substrate, consisting of silver nanoparticles and porous gold nanoparticles was fabricated. </LI> <LI> An additional enhancement contribution generated from the porous characteristic of gold nanoparticles. </LI> <LI> The substrates were used for the detection of a physiological metabolite of urea molecules. </LI> <LI> The results exhibited good quantitative character over all the physiological concentration range (1∼20 mM). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Identification of native charge-transfer status of p-aminothiolphenol adsorbed on noble metallic substrates by surface-enhanced infrared absorption (SEIRA) spectroscopy

Li, Qianwen,Wang, Yanan,Li, Yali,Park, Yeonju,Chen, Yujing,Wang, Xu,Zhao, Bing,Ruan, Weidong,Jung, Young Mee Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.204 No.-

<P><B>Abstract</B></P> <P>p-Aminothiophenol (PATP) is a preferred molecule in research on surface-enhanced Raman scattering (SERS) because of its unique characteristics of high spectral activity, easily induced charge-transfer (CT), and sensitivity to molecular structural changes. However, some aspects are still unclear, such as the initial steady state of PATP on noble metallic substrates without strong additional excitation with incident and/or induced electromagnetic radiation. Information about the initial steady state, especially the intrinsic CT state, is of great importance to elucidate the dynamic processes of CT and/or molecular structural changes under additional excitation. To investigate the native state of an adsorbed molecule, a suitable probe method that does not disrupt the native state of the whole system, including both molecules and substrates, is required. SERS is not applied in this context because of its use of high-energy visible and near-infrared light. Herein, a low-energy probe method, surface-enhanced infrared-absorption (SEIRA) spectroscopy, is employed as a suitable method for studying the native adsorption state of PATP on silver nanoisland films. The molecular structure and adsorption state were investigated. The intrinsic CT state received particular attention by analyzing the CT-related vibration of B<SUB>2</SUB> modes. Using Fourier transform infrared (FTIR), transmission SEIRA and reflection SEIRA spectroscopy, we explained why the relative intensities of some bands were different under different conditions. A quasi-standing orientation of PATP adsorbed on the substrates was also confirmed. More importantly, we demonstrated that there is no perceptible CT between PATP and silver nanoisland films; in contrast, CT generally occurs in a disruptive manner in SERS. Density functional theory (DFT) calculations and the selection rules for infrared (IR) transmission and reflection-absorption spectroscopy were used to analyze the spectra throughout the paper. SEIRA proved to be an effective technique to explore the native adsorption state of molecules without the excessive external disturbance induced by excitation. The results are very important in providing insight into molecules in surface-interface chemistry, enhanced spectroscopy and photoelectronics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The native state of PATP was investigated when adsorbed on silver substrates. </LI> <LI> FTIR and SEIRA allow a probe method with less interference on surfaces. </LI> <LI> The intrinsic charge-transfer state was analyzed through the vibration modes of B<SUB>2</SUB>. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

A reagent-assisted method in SERS detection of methyl salicylate

Li, Yali,Li, Qianwen,Wang, Yanan,Oh, Joohee,Jin, Sila,Park, Yeonju,Zhou, Tieli,Zhao, Bing,Ruan, Weidong,Jung, Young Mee Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.195 No.-

<P><B>Abstract</B></P> <P>With the explosive application of methyl salicylate (MS) molecules in food and cosmetics, the further detection of MS molecules becomes particularly important. Here we investigated the detection of MS molecules based on surface-enhanced Raman scattering (SERS) in a novel molecule/assistant/metal system constructed with MS, 4,4′-(hexafluoroisopropylidene) bis (benzoic acid) and Ag nanoparticles (AgNPs). The minimum detection concentration is 10<SUP>−4</SUP> M. To explore the function of assisted reagent, we also referred another system without assistant molecules. The result demonstrates that SERS signals were not acquired, which proves that the assistant molecules are critical for the capture of MS molecules. Two possible mechanisms of MS/assistant/AgNPs system were speculated through two patterns of hydrogen bonds. The linker molecules acted as the role of the bridge between metallic substrates and target molecules through the molecular recognition. This strategy is very beneficial to the expanding of MS detection techniques and other hydrogen bond based coupling detections with SERS.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel molecule/assistant/metal system was constructed to achieve the SERS detection of methyl salicylate. </LI> <LI> The intermolecular hydrogen bond was employed as the driving force to accomplish the assembly. </LI> <LI> The obstacle of non-adsorption of target molecules on substrates was solved through the hydrogen-bond-based assembly method. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Honokiol Suppresses Renal Cancer Cells’ Metastasis via Dual-Blocking Epithelial-Mesenchymal Transition and Cancer Stem Cell Properties through Modulating miR-141/ZEB2 Signaling

Weidong Li,Qian Wang,Qiaozhen Su,Dandan Ma,Chang An,Lei Ma,Hongfeng Liang 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.5

Renal cell carcinoma (RCC) is associated with a high frequency of metastasis and only few therapies substantially prolong survival. Honokiol, isolated from Magnolia spp. bark, has been shown to exhibit pleiotropic anticancer effects in many cancer types. However, whether honokiol could suppress RCC metastasis has not been fully elucidated. In the present study, we found that honokiol suppressed renal cancer cells’ metastasis via dual-blocking epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties. In addition, honokiol inhibited tumor growth in vivo. It was found that hono-kiol could up-regulate miR-141, which targeted ZEB2 and modulated ZEB2 expression. Honokiol reversed EMT and suppressed CSC properties partly through the miR-141/ZEB2 axis. Our study suggested that honokiol may be a suitable therapeutic strategy for RCC treatment.

Honokiol Suppresses Renal Cancer Cells' Metastasis via Dual-Blocking Epithelial-Mesenchymal Transition and Cancer Stem Cell Properties through Modulating miR-141/ZEB2 Signaling

Li, Weidong,Wang, Qian,Su, Qiaozhen,Ma, Dandan,An, Chang,Ma, Lei,Liang, Hongfeng Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.5

Renal cell carcinoma (RCC) is associated with a high frequency of metastasis and only few therapies substantially prolong survival. Honokiol, isolated from Magnolia spp. bark, has been shown to exhibit pleiotropic anticancer effects in many cancer types. However, whether honokiol could suppress RCC metastasis has not been fully elucidated. In the present study, we found that honokiol suppressed renal cancer cells' metastasis via dual-blocking epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties. In addition, honokiol inhibited tumor growth in vivo. It was found that honokiol could upregulate miR-141, which targeted ZEB2 and modulated ZEB2 expression. Honokiol reversed EMT and suppressed CSC properties partly through the miR-141/ZEB2 axis. Our study suggested that honokiol may be a suitable therapeutic strategy for RCC treatment.

Preparation of biomass-based yam solar absorber for enhanced solar evaporation application

Ting Li,Juan Jia,Yanqing Wang,Hanxue Sun,Jiyan Li,Zhaoqi Zhu,Weidong Liang 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.11

The solar evaporation system has become a research hotspot in the field of photothermal conversion technology in recent years because of its high photothermal conversion efficiency and practicality of promotion. Biomass solar absorbers have excellent solar absorption properties and high solar-water vapor conversion, but they have the limitations of long feedstock production cycle and high carbonization temperature. As a kind of biomass materials, yam is not only inexpensive, but also has a short production cycle and rich pore structures. Therefore, in this paper, a yam based solar absorber with rich pore structure was prepared, and the photothermal conversion efficiency of the absorber was further investigated. The yam was treated with freeze-dried method and carbonized at different temperatures to obtain yam solar absorbers. Then the thermal stability and porosity of solar absorber was found to gradually rise as the treatment temperature increased. The solar absorption rate of the carbonized yam was close to 90% in the near UV-visible region. Solar-water vapor control experiments with different treatments of the solar absorber of the yam were carried out in simulated solar-driven interface steam generation system (SISGS). An absorber treated at 200 °C in the sun was found to have the best performance with a solar-water vapor conversion of about 90% and a water evaporation rate of 1.3164 kg m−2 h−1.

Balantidium honghuensis n. sp. (Ciliophora: Trichostomatidae) from the Rectum of Rana nigromaculata and R. limnocharis from Honghu Lake, China

Ming Li,Weidong Li,Lei Zhang,Chong Wang 대한기생충학열대의학회 2013 The Korean Journal of Parasitology Vol.51 No.4

Biphasic effects of ANP infusion in conscious, euvolumic rats: roles of AQP2 and ENaC trafficking.

Wang, Weidong,Li, Chunling,Nejsum, Lene N,Li, Hongyan,Kim, Soo Wan,Kwon, Tae-Hwan,Jonassen, Thomas E N,Knepper, Mark A,Thomsen, Klaus,Frokiaer, Jorgen,Nielsen, Soren American Physiological Society 2006 American journal of physiology. Renal physiology Vol.290 No.2

<P>Atrial natriuretic peptide (ANP) acutely promotes water and sodium excretion, whereas subchronic effects involve water retention. Renal hemodynamics, water and sodium excretion, and aquaporin-2 (AQP2) and epithelial Na channel (ENaC) subcellular trafficking were determined in response to continuous ANP infusion in conscious rats, where body sodium and fluid balance was constantly maintained. ANP (0.5 microg x kg(-1) x min(-1)) evoked a transient (peak at 10 min) fivefold diuresis followed by reduced urine production to control levels (30- to 90-min period). The fractional distal water excretion was significantly increased initially and then decreased in response to ANP. There was no change in the subcellular localization of AQP2 and AQP2 phosphorylated in PKA consensus site S256 (p-AQP2) 10 min after ANP infusion. In contrast, after 90 min a marked increase in apical labeling of AQP2 and p-AQP2 was observed in the inner and outer medullary collecting ducts but not in cortical collecting ducts. In support of this, ANP induced plasma membrane targeting of AQP2 in transiently AQP2-transfected cells. ANP infusion evoked an instant increase in renal sodium excretion, which persisted for 90 min. Ten minutes of ANP infusion induced no changes in the subcellular localization of ENaC subunits, whereas a marked increase in apical targeting of alpha- and gamma-subunits was observed after 90 min. In conclusion, 1) ANP infusion induced a sustained natriuresis and transient diuresis; 2) there were no changes in the subcellular localization of AQP2 and ENaC subunits after 10 min of ANP infusion; and 3) there was a marked increase in apical targeting of AQP2, p-AQP2, and alpha- and gamma-ENaC after 90 min of ANP infusion. The increased targeting of ENaC and AQP2 likely represents direct or compensatory effects to increase sodium and water reabsorption and to prevent volume depletion in response to prolonged ANP infusion.</P>

Correlation Between Different Antidiarrheal Treatments and Changes in Chemical Components of Allii Sativi Bulbus Before and After Steaming Treatment Based on Flora Sequencing and In Vitro Experiments

Yarong Li,Yaqian Zhou,Huanjin Liu,Chenxu Wei,Shuli Chen,Zhengying Hua,Yan Xu,Yu Wu,Weidong Li 한국식품영양과학회 2022 Journal of medicinal food Vol.25 No.10

We investigated the changes in the main active ingredients and pharmacodynamic differences in the therapeutic effect of garlic before and after steaming and the correlation between them. The main active ingredients in raw garlic products (RGPs) and steamed garlic products (SGPs) were determined by high-pressure liquid chromatography and ultraviolet spectroscopy. Acute rapid diarrhea (AD) and antibiotic-induced diarrhea (DD) models were established in rats, and each group was treated with RGP and SGP, respectively. The main chemical components of garlic changed before and after steaming. Garlicin and alliinase were only found in RGP, whereas only alliin was found in SGP. Both RGP and SGP contained garlic polysaccharides. For in vivo experiments on AD, the average rate of loose stools was 100.00 ± 0.00, 31.55 ± 11.76, and 19.14 ± 6.62 in the RGP high-dose and SGP high-dose treatment groups, respectively; in DD, the rates were 91.11 ± 14.40, 19.33 ± 3.63, and 30.56 ± 4.30, respectively (P < .01, treatment vs. model groups). In AD, the average grade of loose stools was 2.33 ± 0.52 and 1.83 ± 0.75 in the model and RGP high-dose treatment groups, respectively (P < .05); in DD, the values were 2.17 ± 0.41 in the model group and 1.67 ± 0.52 in the SGP high-dose treatment group (P < .05). RGP had a better therapeutic effect on AD, mainly related to the antibacterial effect of garlicin in RGP. SGP had a better therapeutic effect on DD, mainly related to the alliin and garlic polysaccharide in SGP. This study could provide evidence to support the clinical use of garlic.

alpha-MSH prevents impairment in renal function and dysregulation of AQPs and Na-K-ATPase in rats with bilateral ureteral obstruction.

Li, Chunling,Shi, Yimin,Wang, Weidong,Sardeli, Chrysanthi,Kwon, Tae-Hwan,Thomsen, Klaus,Jonassen, Thomas,Djurhuus, Jens Christian,Knepper, Mark A,Nielsen, Soren,Frokiaer, Jorgen American Physiological Society 2006 American Journal of Physiology Vol.290 No.2

<P>The purpose of this study was to evaluate the effects of the anti-inflammatory hormone alpha-melanocyte-stimulating hormone (alpha-MSH) treatment on renal function and expression of aquaporins (AQPs) and Na-K-ATPase in the kidney in response to 24 h of bilateral ureteral obstruction (BUO) or release of BUO (BUO-R). In rats with 24-h BUO, immunoblotting revealed that downregulation of AQP2 and AQP3 was attenuated (AQP2: 38 +/- 5 vs. 13 +/- 4%; AQP3: 44 +/- 3 vs. 19 +/- 4% of sham levels; P < 0.05), whereas downregulation of Na-K-ATPase was prevented by alpha-MSH treatment (Na-K-ATPase: 94 +/- 7 vs. 35 +/- 5% of sham levels; P < 0.05). Immunocytochemistry confirmed the changes in AQP1 and Na-K-ATPase expression. Renal tubular cell apoptosis was confirmed in BUO kidneys, and alpha-MSH treatment virtually completely abolished apoptosis. Furthermore, we measured glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), respectively. Forty-eight hours after BUO-R demonstrated that alpha-MSH treatment almost completely prevented the decrease in GFR (nontreated: 271 +/- 50; alpha-MSH: 706 +/- 85; sham: 841 +/- 105 microl x min(-1).100 g body wt(-1), P < 0.05) and ERPF (nontreated: 1,139 +/- 217; alpha-MSH: 2,598 +/- 129; sham: 2,633 +/- 457 microl x min(-1).100 g body wt(-1), P < 0.05). alpha-MSH treatment also partly prevented the downregulation of AQP1 and Na-K-ATPase expression in rats after BUO-R for 48 h. In conclusion, alpha-MSH treatment significantly prevents impairment in renal function and also prevents downregulation of AQP2, AQP3, and Na-K-ATPase during BUO or AQP1 and Na-K-ATPase after BUO-R, demonstrating a marked renoprotective effect of alpha-MSH treatment in conditions with urinary tract obstruction.</P>