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1.
Mater Horiz ; 2024 May 14.
Article in English | MEDLINE | ID: mdl-38742392

ABSTRACT

Polyurethane (PU) foams, pivotal in modern life, face challenges suh as fire hazards and environmental waste burdens. The current reliance of PU on potentially ecotoxic halogen-/phosphorus-based flame retardants impedes large-scale material recycling. Here, our demonstrated controllable catalytic cracking strategy, using cesium salts, enables self-evolving recycling of flame-retardant PU. The incorporation of cesium citrates facilitates efficient urethane bond cleavage at low temperatures (160 °C), promoting effective recycling, while encouraging pyrolytic rearrangement of isocyanates into char at high temperatures (300 °C) for enhanced PU fire safety. Even in the absence of halogen/phosphorus components, this foam exhibits a substantial increase in ignition time (+258.8%) and a significant reduction in total smoke release (-79%). This flame-retardant foam can be easily recycled into high-quality polyol under mild conditions, 60 °C lower than that for the pure foam. Notably, the trace amounts of cesium gathered in recycled polyols stimulate the regenerated PU to undergo self-evolution, improving both flame-retardancy and mechanical properties. Our controllable catalytic cracking strategy paves the way for the self-evolutionary recycling of high-performance firefighting materials.

2.
Heliyon ; 10(9): e29901, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38694095

ABSTRACT

Aims: To investigate the potential functions and mechanisms of tumourigenesis in carboxypeptidase E (CPE) and its prognostic value in gastric cancer, and to develop a predictive model for prognosis based on CPE. Results: Transcriptome level variation and the prognostic value of CPE in different types of cancers were investigated using bioinformatics analyses. The association between CPE and clinicopathological characteristics was specifically explored in gastric cancer. Elevated CPE expression was associated with poor survival and recurrence prognosis and was found in cases with a later clinical stage of gastric cancer. The CPE was considered an independent prognostic factor, as assessed using Cox regression analysis. The prognostic value of CPE was further verified through immunohistochemistry and haematoxylin staining. Enrichment analysis provided a preliminary confirmation of the potential functions and mechanisms of CPE. Immune cell infiltration analysis revealed a significant correlation between CPE and macrophage infiltration. Eventually, a prognosis prediction nomogram model based on CPE was developed. Conclusion: CPE was identified as an independent biomarker associated with poor prognosis in gastric cancer. This suggests that CPE overexpression promoted epithelial-mesenchymal transition via the activation of the Erk/Wnt pathways, leading to proliferation, invasion, and metastasis. Targeted therapeutic strategies for gastric cancer may benefit from these findings.

3.
Gland Surg ; 13(2): 199-208, 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38455344

ABSTRACT

Background: Breast cancer has become the most frequently diagnosed cancer in the world. Detection at an early stage, frequently allows women to benefit from breast conserving surgery. However, some patients are not satisfied with the breast shape after breast-conserving surgery, and autologous tissue flaps are needed to fill the defect in the resection area. The modified lateral thoracic artery perforator (LTAP) flap isn't one of the commonly used flaps in breast surgery and has the advantages of a reliable blood supply, simple operation and few postoperative complications. In this study, we aimed to evaluate the feasibility and effectiveness of a modified LTAP flap for repairing partial breast defects after breast-conserving surgery. Methods: In this study, we retrospectively analyzed the clinical data of 126 patients treated with LTAP flaps to repair local breast defects at Affiliated Hospital of Guangdong Medical University between January 2020 and June 2021. Data were collected on the demographic characteristics of these patients, tumor size and location, type of axillary lymph node surgery, availability of adjuvant chemotherapy and radiotherapy, and postoperative complications. Results: The median weight of the tumor specimen was 185 g (range, 170-320 g), and this glandular tissue accounted for 30% to 40% of the total breast volume. The average flap size was 10.5 cm ×2.5 cm (length range, 8-15 cm, width range: 2-4 cm). The minimum follow-up time was 6 months, with an average of 10 months (range, 6-22 months). The mean operative time was 130 minutes (range: 90-180 minutes), and the mean hospital stay was 3 days (range, 2-5 days). All modified LTAP flaps survived completely without donor site complications. None of the patients required revision surgery on the postoperative breast. Conclusions: The modified LTAP flap is a reliable method for repairing partial breast defects after breast-conserving surgery. It has the advantages of a simple operation, a reliable blood supply, fewer postoperative complications, and a high flap survival rate. It is especially suitable for Asian women with small breast volumes and can achieve good breast contouring effects.

4.
Article in English | MEDLINE | ID: mdl-38393895

ABSTRACT

 Secretory carcinoma of the breast (SCB) is a rare and specific type of breast cancer. Owing to its rarity, the number of SCB reports available is limited, with most of them focusing on clinical and pathological characteristics but no reports on its multimodal ultrasound (US) features. Thus, we present a rare case of SCB, retrospectively analyzing manifestations of US and contrast-enhanced US, as well as its pathological basis, aiming to enhance the understanding of US image features of SCB and provide more valuable information for clinical diagnosis. Moreover, the treatment strategy adopted for this patient may serve as a template for future management of SCB.

5.
Transl Cancer Res ; 12(6): 1588-1601, 2023 Jun 30.
Article in English | MEDLINE | ID: mdl-37434681

ABSTRACT

Background: Breast cancer is the most common gynecological malignancy and the leading cause of cancer-related deaths in women. P-element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are novel non-coding RNAs whose abnormal expressions have been closely associated with multiple cancers. This study explored the roles and possible mechanisms of piRNA-31106 in breast cancer. Methods: The expression of piRNA-31106 in breast cancer tissues and cells was detected by reverse transcription polymerase chain reaction (RT-PCR). The pcDNA vector containing piRNA-31106 (pcDNA-piRNA-31106) and a short hairpin (sh)RNA containing piRNA-31106 (shRNA-piRNA-31106) were used to interfere with piRNA-31106 expression in breast cancer cells. The effects on cell proliferation, apoptosis/cell cycle, invasion, and metastasis were detected via Cell Counting Kit-8 (CCK-8), flow cytometry, transwell assays, and scratch tests, respectively. The protein expressions of murine double minute 2 (MDM2), cyclin-dependent kinase 4 (CDK4), and cyclinD1 were detected by Western blot analysis. The N6-methyladenosine (m6A) RNA methylation level and the binding relationship between piRNA-31106 and METTL3 were analyzed. The role of METTL3 in the regulation of breast cancer by piRNA-31106 was further analyzed by using small interfering (si)RNA targeting METTL3. Results: PiRNA-31106 was highly expressed in breast cancer tissues and cell lines MDA-MB-231 and MCF-7. Overexpression of piRNA-31106 promoted the viability, invasion, and migration of breast cancer, inhibited apoptosis, and promoted the expressions of MDM2, CDK4, and cyclinD1. Inhibition of piRNA-31106 showed the opposite effect. In addition, piRNA-31106 promoted the m6A methylation levels and facilitated methyltransferase-like 3 (METTL3) expression in MDA-MB-231 and MCF-7 cells. RNA immunoprecipitation (RIP) assays confirmed the binding relationship between piRNA-31106 and METTL3. Further experiments demonstrated that si-METTL3 could inhibit the regulatory effects of piRNA-31106 on breast cancer. Conclusions: PiRNA-31106 was significantly highly expressed in breast cancer and could promote breast cancer progression by regulating METTL3-mediated m6A RNA methylation.

6.
Gland Surg ; 11(9): 1507-1517, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36221279

ABSTRACT

Background: Acquired lymphedema is a common and often severe complication of breast cancer surgery and radiology that seriously affects patients' quality of life. Nevertheless, the pathogenesis for acquired lymphedema is complex and remains unclear. The aim of this study is to find out possible genetic markers and potential drugs for acquired lymphedema. Methods: First, the GSE4333 datasets, which include expression data for six female humanized hairless immunocompetent SKH-1 mice (the condition of whom mimics acquired lymphedema), were reanalyzed. According to the criteria of a fold change (FC) ≥1.4 and an adjusted P value <0.05, we identified the differentially expressed genes (DEGs) between a normal group and the lymphedema group. Next, we analyzed the Gene Ontology (GO) terms and enriched signaling pathways associated with these DEGs with an online tool DAVID. We also constructed protein-protein interaction (PPI) networks and selected meaningful gene modules for additional gene-drug interaction research. Finally, the extant drugs targeting these module genes were identified for further study of their therapeutic effects against acquired lymphedema. Results: A total of 481 DEGs were identified that were closely associated with the immune system, inflammatory response, and extracellular matrix (ECM) structural constituent terms, among others. Moreover, we identified the top 10 significant genes in the PPI networks and identified one extant drug, fiboflapon, that targets the ALOX5AP gene. Conclusions: We ultimately identified 10 hub genes, molecular mechanisms, and one extant drug related to acquired lymphedema. The findings identified targets and a potential drug for further research on acquired lymphedema.

7.
World J Clin Cases ; 10(11): 3505-3510, 2022 Apr 16.
Article in English | MEDLINE | ID: mdl-35582050

ABSTRACT

BACKGROUND: Chronic radiative chest wall ulcers are common in patients undergoing radiation therapy. If not treated early, then symptoms such as erosion, bleeding and infection will appear on the skin. In severe cases, ulcers invade the ribs and pleura, presenting a mortality risk. Small ulcers can be repaired with pedicle flaps. Because radioactive ulcers often invade the thorax, surgeons need to remove large areas of skin and muscle, and sometimes ribs. Repairing large chest wall defects are a challenge for surgeons. CASE SUMMARY: A 74-year-old female patient was admitted to our department with chest wall skin ulceration after radiation therapy for left breast cancer. The patient was diagnosed with chronic radioactive ulceration. After multidisciplinary discussion, the authors performed expansive resection of the chest wall ulcers and repaired large chest wall defects using a deep inferior epigastric perforator (DIEP) flap combined with a high-density polyethylene (HDPE) patch. The patient was followed-up 6 mo after the operation. No pigmentation or edema was found in the flap. CONCLUSION: DIEP flap plus HDPE patch is one of the better treatments for radiation-induced chest wall ulcers.

8.
Gland Surg ; 10(5): 1687-1700, 2021 May.
Article in English | MEDLINE | ID: mdl-34164313

ABSTRACT

BACKGROUND: In recent years, breast cancer is the most common malignancy in women. The traditional method of surgery is to remove a woman's breast completely, which has a negative impact on her work and life. Today, women have a fiery pursuit to maintain their perfect figure, which has forced breast surgeon to find a new surgical approach to maintain the shape of the breast after surgery. METHODS: This study systematically analyzed and summarized the incision design and repair of glandular defects in early-stage breast cancer patients by oncoplastic breast techniques. By summarizing the methods of oncoplastic breast surgery (OBS) in different quadrants, it could help beginners to master this technology more quickly, so as to provide better help for breast cancer patients. RESULTS: A total of 216 breast cancer patients who underwent OBS from January 2016 to June 2020 at the Affiliated Hospital of Guangdong Medical University were included in this study. In patients treated with the volume-displacement method and the volume-replacement method, 92.6% and 86.2% of patients achieved excellent breast shape, respectively. CONCLUSIONS: OBS is a safe and effective way to treat early-stage breast cancer while obtaining better breast shape, reducing postoperative psychological trauma, and improving quality of life.

9.
Annu Rev Phys Chem ; 72: 213-234, 2021 Apr 20.
Article in English | MEDLINE | ID: mdl-33400554

ABSTRACT

Revealing the intrinsic relationships between the structure, properties, and performance of the electrochemical interface is a long-term goal in the electrochemistry and surface science communities because it could facilitate the rational design of electrochemical devices. Achieving this goal requires in situ characterization techniques that provide rich chemical information and high spatial resolution. Electrochemical tip-enhanced Raman spectroscopy (EC-TERS), which provides molecular fingerprint information with nanometer-scale spatial resolution, is a promising technique for achieving this goal. Since the first demonstration of this technique in 2015, EC-TERS has been developed for characterizing various electrochemical processes at the nanoscale and molecular level. Here, we review the development of EC-TERS over the past 5 years. We discuss progress in addressing the technical challenges, including optimizing the EC-TERS setup and solving tip-related issues, and provide experimental guidelines. We also survey the important applications of EC-TERS for probing molecular protonation, molecular adsorption, electrochemical reactions, and photoelectrochemical reactions. Finally, we discuss the opportunities and challenges in the future development of this young technique.

10.
Nanomaterials (Basel) ; 10(12)2020 Dec 19.
Article in English | MEDLINE | ID: mdl-33352752

ABSTRACT

Nobel metal nanohole arrays have been used extensively in chemical and biological systems because of their fascinating optical properties. Gold nanohole arrays (Au NHAs) were prepared as surface plasmon polariton (SPP) generators for the surface-enhanced sum-frequency generation (SFG) detection of 4-Mercaptobenzonitrile (4-MBN). The angle-resolved reflectance spectra revealed that the Au NHAs have three angle-dependent SPP modes and two non-dispersive localized surface plasmon resonance (LSPR) modes under different structural orientation angles (sample surface orientation). An enhancement factor of ~30 was achieved when the SPP and LSPR modes of the Au NHAs were tuned to match the incident visible (VIS) and output SFG, respectively. This multi-mode matching strategy provided flexible controls and selective spectral windows for surface-enhanced measurements, and was especially useful in nonlinear spectroscopy where more than one light beam was involved. The structural orientation- and power-dependent performance demonstrated the potential of plasmonic NHAs in SFG and other nonlinear sensing applications, and provided a promising surface molecular analysis development platform.

11.
Gland Surg ; 9(4): 1048-1055, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32953614

ABSTRACT

Locally advanced breast cancer, which is defined as a malignant breast tumor that invades or adheres to the surrounding tissue, is characterized by the invasion of the chest wall and the skin surface by the tumor. Multiple lymph nodes are invaded and fuse into a mass, causing extensive axillary lymph node metastasis. However, locally advanced breast cancer does not exhibit distant metastasis. At present, in most hospitals in China and the rest of the world, this type of breast cancer is primarily managed through systematic and local treatments. However, a consensus concerning the optimal surgical method for chest wall reconstruction, which for many surgeons is a difficult and confusing procedure, has not been reached. In the past, many breast centers had used skin flap combined with hard mesh titanium alloy plate to repair the large chest wall defects. Although titanium alloy plate can maintain the stability of the chest wall, it may have a negative effect on the follow-up radiotherapy of breast cancer patients, which is a controversial method. In addition, titanium alloy mesh also has the risk of deformation and fracture. These factors will cause some hidden dangers to patient safety. According to the research, the soft mesh not only has the characteristics of satisfactory compatibility and robustness for maintaining the stability of chest wall, but also does not affect the postoperative radiotherapy of patients. Combined with the advantages of soft mesh, Our department treated a case of locally advanced breast cancer with chest wall invasion. Through cooperation between the breast surgery and thoracic surgery departments, a mesh repair plus transverse rectus abdominis myocutaneous (TRAM) combined with deep inferior epigastric perforator (DIEP) procedure was performed to remove the breast tumor and repair the large area of skin defect after surgery, and a relatively satisfactory therapeutic effect was achieved. In this case, we took two novel approaches: first, a 4-layer high-density polyethylene mesh was used to repair the defect; secondly, the inferior epigastric artery perforation was anastomosed with the thoracoacromial artery (end-to-end anastomosis) and the inferior epigastric vein perforation was anastomosed with the axillary vein (end-to-side anastomosis).

12.
Nat Commun ; 11(1): 4211, 2020 Aug 24.
Article in English | MEDLINE | ID: mdl-32839440

ABSTRACT

Surface plasmons (SPs) of metals enable the tight focusing and strong absorption of light to realize an efficient utilization of photons at nanoscale. In particular, the SP-generated hot carriers have emerged as a promising way to efficiently drive photochemical and photoelectric processes under moderate conditions. In situ measuring of the transport process and spatial distribution of hot carriers in real space is crucial to efficiently capture the hot carriers. Here, we use electrochemical tip-enhanced Raman spectroscopy (EC-TERS) to in situ monitor an SP-driven decarboxylation and resolve the spatial distribution of hot carriers with a nanometer spatial resolution. The transport distance of about 20 nm for the reactive hot carriers is obtained from the TERS imaging result. The hot carriers with a higher energy have a shorter transport distance. These conclusions can be guides for the design and arrangement of reactants and devices to efficiently make use of plasmonic hot carriers.

13.
ACS Appl Mater Interfaces ; 12(25): 28700-28710, 2020 Jun 24.
Article in English | MEDLINE | ID: mdl-32479048

ABSTRACT

The leakage and fire hazard of organic solid-liquid phase change material (PCM) tremendously limit its long-term and safe application in thermal energy storage and regulation. In this work, novel nanoflake-fabricated organic-inorganic supramolecular hierarchical microspheres denoted as BPL were synthesized through the electrostatically driven assembly of poly(ethylene ammonium phenylphosphamide) (BP) decorated layered double hydroxides using sodium dodecyl sulfate as a template. Then the BPL was simultaneously utilized as a porous supporting material and flame retardant for polyethylene glycol to fabricate shape-stabilized PCM (BS-PCM). Benefiting from the structural uniqueness of the BPL microsphere, the BS-PCM possessed a high latent heat capacity of 116.7 J g-1 and excellent thermoregulatory capability. Moreover, the BS-PCM had no apparent leakage after a 200-cycle heating/cooling process and showed excellent thermal reversibility, superior to similar solid-liquid PCMs reported in recent literature. More interestingly, unlike flammable PEG, BS-PCM showed excellent fire resistance when exposed to a fire source. The unique BPL porous microsphere provided not only a microcontainer with high storage capacity for solid-liquid PCM, but also a fire resistant barrier to PEG, supplying a promising solution for highly efficient and fire-safe thermal energy storage.

14.
Gland Surg ; 9(2): 463-466, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32420275

ABSTRACT

Modified breast cancer radical mastectomy is a more common operating method in breast surgery. Traditional modified radical mastectomy focuses on protecting the long thoracic nerve and thoracodorsal nerve while ignoring the protection of the anterior thoracic nerve and intercostobrachial nerve protection, which leads often to patients with upper medial arm numbness, acid swelling, pain, chest atrophy, and other problems. In the modified radical mastectomy of breast cancer, in this case, the author used an elaborative operation to protect the anterior thoracic nerve and intercostobrachial nerve and thoroughly dissected the third-level lymph nodes through the axillary approach.

15.
J Am Chem Soc ; 142(3): 1341-1347, 2020 Jan 22.
Article in English | MEDLINE | ID: mdl-31893500

ABSTRACT

Active oxygen species (AOS) play key roles in many important catalytic reactions relevant to clean energy and environment. However, it remains challenging to characterize the active sites for producing AOS and to image the surface properties of AOS, especially on multicomponent metallic catalyst surfaces. Herein, we utilize tip-enhanced Raman spectroscopy (TERS) to probe the local generation and diffusion of OH radicals on a Pd/Au(111) bimetallic catalyst surface. The reactive OH radicals can be catalytically generated from hydrogen peroxide (H2O2) at the metal surface, which then oxidizes the surface adsorbed thiolate, a reactant that is used as the TERS probe. By TERS imaging of the spatial distribution of unreacted thiolate molecules, we demonstrate that the Pd surface is active for generation of OH radicals and the Pd step edge shows much higher activity than the Pd terrace, whereas the Au surface is inactive. Furthermore, we find that the locally generated OH radicals at the Pd step edge could diffuse to both the Au and the Pd surface sites to induce oxidative reactions, with a diffusion length estimated to be about 5.4 nm. Our TERS imaging with few-nanometer spatial resolution not only unravels the active sites but also characterizes in real space the diffusion behavior of OH radicals. The results are highly valuable to understand AOS-triggered catalytic reactions. The strategy of using reactants with large Raman cross sections as TERS probes may broaden the application of TERS for studying catalysis with reactive small molecules.

16.
Luminescence ; 35(1): 52-61, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31410969

ABSTRACT

The over-use of antibiotics has caused a number of problems such as contamination of antibiotic residues and virus resistance, and therefore has attracted global attention. In this study, spectroscopic techniques and molecular docking were employed to predict conformational changes and binding interaction between two cephalosporins (cefaclor and cefixime) and calf thymus DNA (ctDNA). Fluorescence and UV-vis spectra suggested that static quenching was predominant and cephalosporin bound to the groove region of ctDNA. Binding parameters calculated by the Stern-Volmer and Scatchard equations showed that cephalosporin bound to ctDNA with a binding affinity in the order of 103  L mol-1 . Thermodynamic parameters further indicated that the reaction was a spontaneous process driven by enthalpy and entropy, and that the main binding force was an electrostatic force. The effects of iodide, denaturant, thermal denaturation and pH on a cephalosporin-Hoechst-DNA complex were also studied, and the results confirmed that cephalosporin bound to the groove area of DNA. Finally, these results were further confirmed by molecular docking and electrochemical studies.


Subject(s)
Anti-Bacterial Agents/chemistry , Cefaclor/chemistry , Cefixime/chemistry , DNA/chemistry , Electrochemical Techniques , Molecular Docking Simulation , Animals , Binding Sites , Cattle , Hydrogen-Ion Concentration , Molecular Conformation , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , Thermodynamics
17.
Nat Commun ; 10(1): 5544, 2019 12 05.
Article in English | MEDLINE | ID: mdl-31804496

ABSTRACT

Defects can induce drastic changes of the electronic properties of two-dimensional transition metal dichalcogenides and influence their applications. It is still a great challenge to characterize small defects and correlate their structures with properties. Here, we show that tip-enhanced Raman spectroscopy (TERS) can obtain distinctly different Raman features of edge defects in atomically thin MoS2, which allows us to probe their unique electronic properties and identify defect types (e.g., armchair and zigzag edges) in ambient. We observed an edge-induced Raman peak (396 cm-1) activated by the double resonance Raman scattering (DRRS) process and revealed electron-phonon interaction in edges. We further visualize the edge-induced band bending region by using this DRRS peak and electronic transition region using the electron density-sensitive Raman peak at 406 cm-1. The power of TERS demonstrated in MoS2 can also be extended to other 2D materials, which may guide the defect engineering for desired properties.

18.
Anal Chem ; 91(17): 11092-11097, 2019 Sep 03.
Article in English | MEDLINE | ID: mdl-31361476

ABSTRACT

Electrochemical tip-enhanced Raman spectroscopy (EC-TERS) appears as a promising in situ nanospectroscopic tool for characterization and understanding of the electrochemical interfacial processes at the nanometer scale and molecular level. However, the wide application of EC-TERS is hampered by its low sensitivity as a result of the optical path distortion due to the refractive index mismatch of the multilayer media (air, glass, and electrolyte). Here, we propose a new side-illumination EC-TERS setup by coupling a water immersion objective with a high numerical aperture to a scanning tunneling microscope scanning head customized with a large open space and a compact spectroelectrochemical cell. It not only effectively eliminates the optical distortion but also increases the sensitivity remarkably, which allows sensitive monitoring of the electrochemical redox processes of anthraquinone molecules. More importantly, EC-TERS is able to independently control the tip position and laser illumination position. By utilizing this feature, we reveal that the irreversible reduction reaction of anthraquinone observed in EC-TERS is induced by the synergistic effect of the negative potential and laser illumination rather than the localized surface plasmon. The highly improved sensitivity and the flexibility to control the tip and laser illumination position on the nanometer scale endows EC-TERS as an important tool for the fundamental understanding of the photo- or plasmon electrochemistry and the interfacial structure-activity relationship of important electrochemical systems.

19.
J Phys Chem Lett ; 10(10): 2306-2312, 2019 May 16.
Article in English | MEDLINE | ID: mdl-31013094

ABSTRACT

In the field of surface plasmon-mediated photocatalysis, the coupling reactions of p-aminothiophenol (PATP) and p-nitrothiophenol (PNTP) to produce p, p'-dimercaptoazobenzene (DMAB) are the most widely investigated systems. However, a clear understanding of the structure-function relationship is still required. Here, we used tip-enhanced Raman spectroscopy (TERS) to study the coupling reactions of PATP and PNTP on well-defined Ag(111) and Au(111) surfaces using 632.8 and 532 nm lasers. On Au(111), the oxidative coupling of PATP can proceed under irradiation by a 632.8 nm laser, and the reductive coupling of PNTP can only occur under irradiation by a 532 nm laser. Neither wavelength of laser light can induce the coupling reactions of these two molecules on Ag(111). Density functional theory (DFT) was used to calculate the stable adsorption configurations of PATP and PNTP on Ag(111) and Au(111). Both the adsorption configurations of the two molecules on the surfaces and laser energies were, experimentally and theoretically, found to determine whether the coupling reactions can occur on different substrates. These results may help the rational design of photocatalysts with enhanced reactivity.

20.
Angew Chem Int Ed Engl ; 57(25): 7523-7527, 2018 06 18.
Article in English | MEDLINE | ID: mdl-29645335

ABSTRACT

Tip-enhanced Raman spectroscopy can provide molecular fingerprint information with ultrahigh spatial resolution, but the tip will be easily contaminated, thus leading to artifacts. It also remains a great challenge to establish tip-enhanced fluorescence because of the quenching resulting from the proximity of the metal tip. Herein, we report shell-isolated tip-enhanced Raman and fluorescence spectroscopies by employing ultrathin shell-isolated tips fabricated by atomic layer deposition. Such shell-isolated tips not only show outstanding electromagnetic field enhancement in TERS but also exclude interference by contaminants, thus greatly promoting applications in solution. Tip-enhanced fluorescence has also been achieved using these shell-isolated tips, with enhancement factors of up to 1.7×103 , consistent with theoretical simulations. Furthermore, tip-enhanced Raman and fluorescence signals are acquired simultaneously, and their relative intensities can be manipulated by changing the shell thickness. This work opens a new avenue for ultrahigh resolution surface analysis using plasmon-enhanced spectroscopies.

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