Size and Wavelength Dependence of the Charge-Transfer Contributions to Surface-Enhanced Raman Spectroscopy in Ag/PATP/ZnO Junctions

By use of surface-enhanced Raman spectroscopy, we observe the degree of charge-transfer for Ag/PATP/ZnO sandwich compounds as a function of both ZnO nanoparticle size and as a function of excitation wavelength. We show that there are several likely charge-transfer resonances. The most obvious is the resonance at particle diameter of 27.7 nm for all wavelengths. In a theoretical study it has been suggested that when there is an electron acceptor on the nanoparticle surface it may form a complex with the semiconductor exciton and that this is most likely the origin of the size-dependent resonance. At the smallest size (18.2 nm) studied here, there is an increase in degree of charge-transfer (relative to adjacent sizes), indicating the possibility of another, lower-lying charge-transfer state, which also could be caused by the acceptor−exciton complex. The other resonance suggested by our data is to higher excitation energy for all particle sizes. It can be seen that the degree of charge-transfer is rising as the excitation wavelength is shortened, indicating an additional charge-transfer resonance in the ultraviolet

Highly Sensitive Protein Concentration Assay over a Wide Range via Surface-Enhanced Raman Scattering of Coomassie Brilliant Blue

In the Bradford protein assay, protein concentrations are determined by the absorbance at 595 nm due to the binding of Coomassie brilliant blue G-250 (CBBG) to proteins. In a protein−CBBG liquid mixture, surface-enhanced Raman scattering (SERS) is sensitive to the amount of unbound CBBG molecules adsorbed on silver surfaces, and the bound CBBG amount is directly related to the target protein concentration. Accordingly, a novel method for detecting total protein concentration in a solution has been developed based on SERS of unbound CBBG with an internal standard of silicon. Two obvious advantages of the proposed protein assay over conventional Bradford protein assay are its much wider linear concentration range (10−5−10−9 g/mL) and 200 times lower limit of detection (1 ng/mL), which demonstrates its great potential in rapid, highly sensitive concentration determination of high and low-abundance proteins

Understanding Metal–Semiconductor Plasmonic Resonance Coupling through Surface-Enhanced Raman Scattering

Although there has been intense research on plasmon-induced charge transfer within metal/semiconductor heterostructures, previous studies have all focused on the surface plasmonic resonance (SPR) of only noble metals. Herein and for the first time, we observe and take into account the plasmonic coupling between SPR of both noble-metal and semiconductor nanostructures. A W18O49/Ag heterostructure composed of metallic Ag nanoparticles (Ag NPs) and semiconducting W18O49 nanowires (W18O49 NWs) is designed and fabricated, which exhibits a broad and strong SPR absorption in the visible wavelength range. This SPR band is attributed to the SPR coupling between the SPR of both Ag NPs and W18O49 NWs. Surface-enhanced Raman scattering (SERS) is then used to reveal the interactions between the metal SPR, semiconductor SPR, and the heterostructure’s charge transfer (CT) process, demonstrating that such coupled SPR enhanced the heterostructure’s internal CT and SERS signals. Finally, we proposed a new coupled-plasmon-induced charge transfer mechanism to interpret the improved CT efficiency between the SERS substrate and molecules. Our work provides insight for further studies on plasmonic effects and interfacial charge transfer in metal/semiconductor heterostructures

Image_5_Effects of immersion in a simulated natural environment on stress reduction and emotional arousal: A systematic review and meta-analysis.TIF

BackgroundAlthough the mental health benefits of exposure to simulated natural environments are well established by researchers from environmental psychology, landscape architecture, and public health, it is unclear whether and to what extent technological immersion affects these benefits.MethodsSystematical literature searches were conducted in May 2022 from six databases. The risk of bias was evaluated using the Cochrane’s Risk of Bias tool 2.0 and the Risk of Bias in Non-randomized Studies of Interventions tool. We performed a random-effects meta-regression to investigate the heterogeneity. The immersion levels of included studies were classified by projection devices and motion capture, and then subgroup analysis was conducted.ResultsTwenty-six publications were included. Exposure to simulated nature was confirmed to be associated with increased positive affect 0.40 [95% confidence interval (CI): 0.22, 0.58], vigor 0.58 (95% CI: 0.30, 0.86), calmness 0.54 (95% CI: 0.17, 0.92) and decreased perceived stress −0.38 (95% CI: −0.71, −0.06), total mood disturbance −0.87 (95% CI: −1.17, −0.57), tension −0.70 (95% CI: −0.99, −0.41), fatigue −0.60 (95% CI: −0.91, −0.28), anxiety −0.72 (95% CI: −1.43, −0.02), depression −0.33 (95% CI: −0.52, −0.14), confusion −0.79 (95% CI: −1.19, −0.40), and anger −0.54 (95% CI: −0.76, −0.31). Gender, health status, study design, mean age, and single exposure duration were not significant when entered in a meta-regression. For positive affect, medium immersion was observed to produce a larger effect than low and high immersion. All included studies had a moderate to high risk of bias.ConclusionAudio-visual exposure to simulated nature contributes to stress relief and emotional arousal. The immersion level explains the heterogeneity of positive affect triggered by simulated nature. Focusing on the technical features will open up new possibilities for combining actual and simulated nature’s mental health benefits.</p

Preparation of Al₂O₃–CeO₂ by Hydrothermal Method Supporting Copper Oxide for the Catalytic Oxidation of CO and C₃H₈

A series of Al2O3–CeO2 carriers were synthesized by hydrothermal method, and CuO/Al2O3–CeO2 catalysts were prepared by ultrasound-assisted impregnation for the catalytic oxidation of CO and C3H8. These prepared samples have been characterized by XRD, BET, TEM, XPS, and other techniques. The 15 wt % CuO/A1C1 catalyst exhibited the best catalytic activity, and the light-off temperatures (T50) of CO and C3H8 were 67 and 325 °C, respectively. XRD results showed that the dispersion of CuO on the catalyst surface was improved by the introduction of CeO2 into the CuO/Al2O3 catalyst. Besides, with the addition of CeO2 content, the specific surface area and pore volume of the sample gradually decrease. XPS results suggest that the synergistic effect (Ce3+ + Cu2+ ↔ Ce4+ + Cu+) is conducive to the generation of oxygen vacancies and improves the activity of the catalyst. Both H2-TPR and O2-TPD temperatures shift toward lower temperatures, indicating that redox reactions are more likely to occur. Finally, based on the results of in situ DRIFTS, the surface Cu+ species obtained from the reduction of Cu2+ play a crucial role in the catalytic oxidation of CO and C3H8

Coupling Reaction-Based Ultrasensitive Detection of Phenolic Estrogens Using Surface-Enhanced Resonance Raman Scattering

Studies have shown that many adverse health effects are associated with human exposure to dietary or environmental estrogens. Therefore, the development of rapid and highly sensitive detection methods for estrogens is very important and necessary to maintain hormonal concentration below the safety limit. Herein, we demonstrate a simple and rapid approach to detect trace amounts of phenolic estrogen based on surface-enhanced resonance Raman scattering (SERRS). Because of a coupling reaction between diazonium ions and the phenolic estrogens, azo compounds are formed with strong SERRS activity, which allows phenolic estrogen recognition at subnanomolar levels in solution. The proposed protocol has multiplexing capability, because each SERRS fingerprint of the azo dyes specifically corresponds to the related estrogen. Moreover, it is universal and highly selective, not only for phenolic estrogens but also for other phenolic molecules, even in complex systems

Image_6_Effects of immersion in a simulated natural environment on stress reduction and emotional arousal: A systematic review and meta-analysis.TIF

BackgroundAlthough the mental health benefits of exposure to simulated natural environments are well established by researchers from environmental psychology, landscape architecture, and public health, it is unclear whether and to what extent technological immersion affects these benefits.MethodsSystematical literature searches were conducted in May 2022 from six databases. The risk of bias was evaluated using the Cochrane’s Risk of Bias tool 2.0 and the Risk of Bias in Non-randomized Studies of Interventions tool. We performed a random-effects meta-regression to investigate the heterogeneity. The immersion levels of included studies were classified by projection devices and motion capture, and then subgroup analysis was conducted.ResultsTwenty-six publications were included. Exposure to simulated nature was confirmed to be associated with increased positive affect 0.40 [95% confidence interval (CI): 0.22, 0.58], vigor 0.58 (95% CI: 0.30, 0.86), calmness 0.54 (95% CI: 0.17, 0.92) and decreased perceived stress −0.38 (95% CI: −0.71, −0.06), total mood disturbance −0.87 (95% CI: −1.17, −0.57), tension −0.70 (95% CI: −0.99, −0.41), fatigue −0.60 (95% CI: −0.91, −0.28), anxiety −0.72 (95% CI: −1.43, −0.02), depression −0.33 (95% CI: −0.52, −0.14), confusion −0.79 (95% CI: −1.19, −0.40), and anger −0.54 (95% CI: −0.76, −0.31). Gender, health status, study design, mean age, and single exposure duration were not significant when entered in a meta-regression. For positive affect, medium immersion was observed to produce a larger effect than low and high immersion. All included studies had a moderate to high risk of bias.ConclusionAudio-visual exposure to simulated nature contributes to stress relief and emotional arousal. The immersion level explains the heterogeneity of positive affect triggered by simulated nature. Focusing on the technical features will open up new possibilities for combining actual and simulated nature’s mental health benefits.</p

Image_7_Effects of immersion in a simulated natural environment on stress reduction and emotional arousal: A systematic review and meta-analysis.TIF

BackgroundAlthough the mental health benefits of exposure to simulated natural environments are well established by researchers from environmental psychology, landscape architecture, and public health, it is unclear whether and to what extent technological immersion affects these benefits.MethodsSystematical literature searches were conducted in May 2022 from six databases. The risk of bias was evaluated using the Cochrane’s Risk of Bias tool 2.0 and the Risk of Bias in Non-randomized Studies of Interventions tool. We performed a random-effects meta-regression to investigate the heterogeneity. The immersion levels of included studies were classified by projection devices and motion capture, and then subgroup analysis was conducted.ResultsTwenty-six publications were included. Exposure to simulated nature was confirmed to be associated with increased positive affect 0.40 [95% confidence interval (CI): 0.22, 0.58], vigor 0.58 (95% CI: 0.30, 0.86), calmness 0.54 (95% CI: 0.17, 0.92) and decreased perceived stress −0.38 (95% CI: −0.71, −0.06), total mood disturbance −0.87 (95% CI: −1.17, −0.57), tension −0.70 (95% CI: −0.99, −0.41), fatigue −0.60 (95% CI: −0.91, −0.28), anxiety −0.72 (95% CI: −1.43, −0.02), depression −0.33 (95% CI: −0.52, −0.14), confusion −0.79 (95% CI: −1.19, −0.40), and anger −0.54 (95% CI: −0.76, −0.31). Gender, health status, study design, mean age, and single exposure duration were not significant when entered in a meta-regression. For positive affect, medium immersion was observed to produce a larger effect than low and high immersion. All included studies had a moderate to high risk of bias.ConclusionAudio-visual exposure to simulated nature contributes to stress relief and emotional arousal. The immersion level explains the heterogeneity of positive affect triggered by simulated nature. Focusing on the technical features will open up new possibilities for combining actual and simulated nature’s mental health benefits.</p

Label-Free Highly Sensitive Detection of Proteins in Aqueous Solutions Using Surface-Enhanced Raman Scattering

We detected concentration-dependent surface-enhanced Raman scattering (SERS) spectra of several label-free proteins (lysozyme, ribonuclease B, avidin, catalase, and hemoglobin) for the first time in aqueous solutions. Acidified sulfate was used as an aggregation agent to induce high electromagnetic enhancement in SERS. Strong SERS spectra of simple and conjugated protein samples could easily be accessed after the pretreatment with the aggregation agent. The detection limits of the proposed method for lysozyme and catalase were as low as 5 μg/mL and 50 ng/mL, respectively. This detection protocol for label-free proteins has combined simplicity, sensitivity, and reproducibility and allows routine qualitative and relatively quantitative detections. Thus, it has great potential in practical high-throughput protein detections

Table_1_Effects of immersion in a simulated natural environment on stress reduction and emotional arousal: A systematic review and meta-analysis.DOCX

BackgroundAlthough the mental health benefits of exposure to simulated natural environments are well established by researchers from environmental psychology, landscape architecture, and public health, it is unclear whether and to what extent technological immersion affects these benefits.MethodsSystematical literature searches were conducted in May 2022 from six databases. The risk of bias was evaluated using the Cochrane’s Risk of Bias tool 2.0 and the Risk of Bias in Non-randomized Studies of Interventions tool. We performed a random-effects meta-regression to investigate the heterogeneity. The immersion levels of included studies were classified by projection devices and motion capture, and then subgroup analysis was conducted.ResultsTwenty-six publications were included. Exposure to simulated nature was confirmed to be associated with increased positive affect 0.40 [95% confidence interval (CI): 0.22, 0.58], vigor 0.58 (95% CI: 0.30, 0.86), calmness 0.54 (95% CI: 0.17, 0.92) and decreased perceived stress −0.38 (95% CI: −0.71, −0.06), total mood disturbance −0.87 (95% CI: −1.17, −0.57), tension −0.70 (95% CI: −0.99, −0.41), fatigue −0.60 (95% CI: −0.91, −0.28), anxiety −0.72 (95% CI: −1.43, −0.02), depression −0.33 (95% CI: −0.52, −0.14), confusion −0.79 (95% CI: −1.19, −0.40), and anger −0.54 (95% CI: −0.76, −0.31). Gender, health status, study design, mean age, and single exposure duration were not significant when entered in a meta-regression. For positive affect, medium immersion was observed to produce a larger effect than low and high immersion. All included studies had a moderate to high risk of bias.ConclusionAudio-visual exposure to simulated nature contributes to stress relief and emotional arousal. The immersion level explains the heterogeneity of positive affect triggered by simulated nature. Focusing on the technical features will open up new possibilities for combining actual and simulated nature’s mental health benefits.</p