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>

Benzyladenine and Gibberellin Affect Runner Formation in Strawberry ‘Sulhyang’ and ‘Maehyang’

Yali Li,Jiangtao Hu,Hao Wei,Dong Il Kang,Yoo Gyeong Park,Byoung Ryong Jeong 한국원예학회 2019 한국원예학회 학술발표요지 Vol.2019 No.10

Optimal Photoperiod for Runner Induction in Strawberry ‘Seolhyang’ and ‘Maehyang’

Yali Li,Jiangtao Hu,Jie Xiao,Byoung Ryong Jeong 한국원예학회 2020 한국원예학회 학술발표요지 Vol.2020 No.11

Characteristics of Morphological and Physiological Changes during the Autolysis Process of Saccharomyces cerevisiae FX-2

Li, Xiao,Shi, Xiaodan,Zou, Man,Luo, Yudi,Tan, Yali,Wu, Yexu,Chen, Lin,Li, Pei The Korean Society for Microbiology and Biotechnol 2015 한국미생물·생명공학회지 Vol.43 No.3

In this paper, the autolysis process of Saccharomyces cerevisiae FX-2 (S. cerevisiae FX-2) via, a variety of endogenous enzyme, was investigated systematically by analyzing changes in physicochemical parameters in autolysate, surface morphology and the internal structure of the yeast cells. As an explicit conclusion, the arisen autolysis depended on the pH and the optimal pH was found to be 5.5. Based on the experimental data and the characteristics of mycelia morphology, a hypothesis is put forward that simple proteins in yeast vacuolar are firstly degraded for utilization, and then more membrane-bound proteins are hydrolyzed to release hydrolytic enzymes, which arouse an enzymatic reaction to induce the collapse of the cell wall into the cytoplasm.

A Comparison of Eu-Doped -Fe2O3 Nanotubes and Nanowires for Acetone Sensing

Yali Cheng,Yifang Wang,Jinbao Zhang,Haiying Li,Li Liu,Yu Lina,Liting Du,Haojie Duan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.11

Pure and Eu-doped (1.0, 3.0, 5.0 wt.%) α-Fe2O3 (PFO and EFO) nanotubes and nanowires have been successfully synthesized through the combination of electrospinning and calcination techniques. The structures, morphologies and chemical compositions of the as-obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric and differential scanning calorimetry (TG-DSC) and energy dispersive spectrum (EDS), respectively. To demonstrate the superior gas sensing performance of the doped nanotubes, a contrastive gas sensing study between PFO (EFO) nanotubes and nanowires was performed. It turned out that Eu doping could magnify the impact of morphology on gas sensitivity. Specifically, at the optimum operating temperature of 240 ℃, the response value of PFO nanotubes to 100 ppm acetone is slightly higher than that of nanowires (3.59/2.20). EFO (3.0 wt.%) nanotubes have a response of 84.05, which is almost 2.7 times as high as that of nanowires (31.54). Moreover, they possess more rapid response/recovery time (11 s and 36 s, respectively) than nanowires (17 s and 40 s, respectively). The lowest detection limit for acetone is 0.1 ppm and its response is 2.15. In addition, both of EFO nanotubes and nanowires sensors have a good linearity (0.1–500 ppm) and favorable selectivity in acetone detection.

How Competitive Orientation Influences Unethical Decision-making in Clinical Practices?

Yali Li,Taiwen Feng,Wenbo Jiang 한국간호과학회 2018 Asian Nursing Research Vol.12 No.3

Purpose: This study aims to investigate how competitive orientation influences unethical decisionmaking (UDM) through relationship conflict and the moderating effect of hostile attribution bias. Methods: This study was conducted using a self-report questionnaire. Data were collected from 727 employees in Chinese hospitals. For each variable, measures were adopted or adapted from existing literature. Data were analyzed using descriptive statistics, correlation analysis, confirmatory factor analysis, and hierarchical regression analysis. Common method variance was established using Harman's single-factor test. Results: Competitive orientation is significantly and positively associated with relationship conflict (b = .36, p < .001) and UDM (b = .35, p < .001). Relationship conflict is significantly and positively associated with UDM (b = .51, p < .001). Relationship conflict partially mediates the relationship between competitive orientation and UDM. In addition, hostile attribution bias strengthens the positive relationship between competitive orientation and UDM through relationship conflict. Conclusion: This study provides some implications for hospital employees to deal with ethical dilemmas in decision-making. Hospital employees including nurses, physicians, and other health-care professionals should raise awareness of competitive orientation and adopt a cooperative approach to human relations. Effective training programs should be utilized to direct all hospital employees to depress hostile attribution bias whenever possible to everything in clinical practice.

The Impact of Self-Efficacy on Nurses’ Well-Being: Does Digital Competence Matter?

Li, Yali,Jing, Qi,Feng, Taiwen,Yang, Xiaoling 한국간호과학회 2023 Journal of Korean Academy of Nursing Vol.53 No.4

Purpose: Drawing on person–environment fit theory and social cognitive theory, this study aimed to examine how self-efficacy affects nurses’ workplace well-being via person-job fit and the moderating role of digital competence. Methods: A two-wave survey was conducted to collect data. Data were collected from six hundred and ninety-five nurses at three Chinese hospitals between May 2022 and September 2022. We employed hierarchical regression analysis and bootstrapping to analyze the data. Results: Self-efficacy positively influenced person-job fit (β = .55, p < .001), which positively affected nurses’ workplace well-being (β = .32, p < .001). Person-job fit mediated the effect of self-efficacy on nurses’ workplace well-being. Additionally, digital competence strengthened the positive impact of self-efficacy on person-job fit (β = .12, p < .001). Conclusion: Recruiting nurses with both self-efficacy and digital competence benefits hospitals. It is critical for nurses to improve their digital competence for achieving person-job fit and attaining workplace well-being in the post-coronavirus disease 2019 (COVID-19) era.

Qualitative and quantitative analysis of furosine in fresh and processed ginsengs

Li, Yali,Liu, Xiaoxu,Meng, Lulu,Wang, Yingping The Korean Society of Ginseng 2018 Journal of Ginseng Research Vol.42 No.1

Background: Furosine (${\varepsilon}$-N-2-furoylmethyl-L-lysine, FML) is an amino acid derivative, which is considered to be an important indicator of the extent of damage (deteriorating the quality of amino acid and proteins due to a blockage of lysine and a decrease in the digestibility of proteins) during the early stages of the Maillard reaction. In addition, FML has been proven to be harmful because it is closely related to a variety of diseases such as diabetes. The qualitative analysis of FML in fresh and processed ginsengs was confirmed using HPLC-MS. Methods: An ion-pair reversed-phase LC method was used for the quantitative analysis of FML in various ginseng samples. Results: The contents of FML in the ginseng samples were 3.35-42.28 g/kg protein. The lowest value was observed in the freshly collected ginseng samples, and the highest value was found in the black ginseng concentrate. Heat treatment and honey addition significantly increased the FML content from 3.35 g/kg protein to 42.28 g/kg protein. Conclusion: These results indicate that FML is a promising indicator to estimate the heat treatment degree and honey addition level during the manufacture of ginseng products. The FML content is also an important parameter to identity the quality of ginseng products. In addition, the generation and regulation of potentially harmful Maillard reaction products-FML in ginseng processing was also investigated, providing a solid theoretical foundation and valuable reference for safe ginseng processing.