Phase-Tunable Molybdenum Boride Ceramics as an Emerging Sensitive and Reliable SERS Platform in Harsh Environments.

Traditional surface-enhanced Raman scattering (SERS) sensors rely heavily on the use of plasmonic noble metals, which have limitations due to their high cost and lack of physical and chemical stability. Hence, it is imperative to explore new materials as SERS platforms that can withstand high temperatures and harsh conditions. In this study, the SERS effect of molybdenum boride ceramic powders is presented with an enhancement factor of 5 orders, which is comparable to conventional noble metal substrates. The molybdenum boride powders synthesized through liquid-phase precursor and carbothermal reduction have ß-MoB, MoB2, and Mo2B5 phases. Among these phases, ß-MoB demonstrates the most significant SERS activity, with a detection limit for rhodamine 6G (R6G) molecules of 10-9 m. The impressive SERS enhancement can be attributed to strong molecule interactions and prominent charge interactions between R6G and the various phases of molybdenum boride, as supported by theoretical calculations. Additionally, Raman measurements show that the SERS activity remains intact after exposure to high temperature, strong acids, and alkalis. This research introduces a novel molybdenum boride all-ceramic SERS platform capable of functioning in harsh conditions, thereby showing the promising of boride ultrahigh-temperature ceramics for detection applications in extreme environments.

Non-pharmacological interventions for smoking cessation: analysis of systematic reviews and meta-analyses.

BACKGROUND: Although non-pharmacological smoking cessation measures have been widely used among smokers, current research evidence on the effects of smoking cessation is inconsistent and of mixed quality. Moreover, there is a lack of comprehensive evidence synthesis. This study seeks to systematically identify, describe, and evaluate the available evidence for non-pharmacological interventions in smoking populations through evidence mapping (EM), and to search for best-practice smoking cessation programs. METHODS: A comprehensive search for relevant studies published from the establishment of the library to January 8, 2023, was conducted in PubMed, Web of Science, Embase, the Cochrane Library, CNKI, CBM, Wan Fang, and VIP. Two authors independently assessed eligibility and extracted data. The PRISMA statement and AMSTAR 2 tool were used to evaluate the report quality and methodology quality of systematic reviews/meta-analyses (SRs/MAs), respectively. Bubble plots were utilized to display information, such as the study population, intervention type, evidence quality, and original study sample size. RESULTS: A total of 145 SRs/MAs regarding non-pharmacological interventions for smoking cessation were investigated, with 20 types of interventions identified. The most commonly used interventions were cognitive behaviour education (n = 32, 22.07%), professional counselling (n = 20, 13.79%), and non-nicotine electronic cigarettes (e-cigarettes) (n = 13, 8.97%). Among them, counselling and behavioural support can improve smoking cessation rates, but the effect varies depending on the characteristics of the support provided. These findings are consistent with previous SRs/MAs. The general population (n = 108, 74.48%) was the main cohort included in the SRs/MAs. The total score of PRISMA for the quality of the reports ranged from 8 to 27, and 13 studies (8.97%) were rated as high confidence, and nine studies (6.21%) as moderate confidence, in the AMSTAR 2 confidence rating. CONCLUSIONS: The abstinence effect of cognitive behaviour education and money incentive intervention has advantages, and non-nicotine e-cigarettes appear to help some smokers transition to less harmful replacement tools. However, the methodological shortcomings of SRs/MAs should be considered. Therefore, to better guide future practice in the field of non-pharmacological smoking cessation, it is essential to improve the methodological quality of SRs and carry out high-quality randomized controlled trials (RCTs).

Engineered Macrophage-Membrane-Coated Nanoparticles with Enhanced PD-1 Expression Induce Immunomodulation for a Synergistic and Targeted Antiglioblastoma Activity.

Glioblastoma (GBM), the most common subtype of malignant gliomas, is characterized by aggressive infiltration, high malignancy, and poor prognosis. The frustrating anti-GBM outcome of conventional therapeutics is due to the immunosuppressive milieu, in addition to the formidable obstacle of the blood-brain barrier (BBB). Combination therapy with an immune checkpoint blockade (ICB) has emerged as a critical component in the treatment of GBM. Here, we report an engineered macrophage-membrane-coated nanoplatform with enhanced programmed cell death-1 (PD-1) expression (PD-1-MM@PLGA/RAPA). Using both in vitro and in vivo GBM models, we demonstrate that PD-1-MM@PLGA/RAPA can efficiently traverse across the BBB in response to the tumor microenvironment (TME) recruitment with nanoparticles accumulating at the tumor site. Furthermore, we show a boosted immune response as a result of enhancing CD8+ cytotoxic T-lymphocyte (CTL) infiltration. Together we provide a new nanoplatform for enhancing ICB in combination with conventional chemotherapy for GBM and many other cancers.

High-intensity focused ultrasound treatment as an alternative regimen for myxofibrosarcoma.

Myxofibrosarcoma is a common soft-tissue sarcoma in elderly patients, characterized by an infiltrative growth pattern and a high risk for persistent local recurrence. A 35-years-old woman was diagnosed with myxofibrosarcoma on the right upper arm and the tumor is surgically resected. The tumor relapsed 7 months later. Then the patient received five cycles of low power cumulative high-intensity focused ultrasound (HIFU) treatments, which completely ablated the tumor without complications. Now the patient is disease free with a high quality of life more than 30 months. This case indicates HIFU ablation might be a novel, promising therapy for recurrent myxofibrosarcoma.

The efficacy of a new high-intensity focused ultrasound therapy for metastatic pancreatic cancer.

PURPOSE: To compare the survival benefit, pain control and safety of low-power cumulative and traditional high-intensity focused ultrasound (HIFU) for metastatic pancreatic cancer. METHOD: We retrospectively analyzed 55 patients with metastatic pancreatic cancer who received HIFU treatment between January 2008 and April 2014 in our department. 23 patients received low-power cumulative HIFU treatment (L group), 32 received the traditional HIFU treatment (T group). Performance status, cancer-related pain and serum biochemistry results were assessed before and after treatment. All patients were followed up until death. The survival rate and adverse events of the two groups were compared. RESULTS: The baseline characteristics of the two groups were generally well balanced (p > 0.05). The average KPS score after treatment was significantly improved in both groups compared with the baseline score. 36 patients exhibited tumor-related pain at baseline. The pain response rate was significantly higher in the L group (92.3%) than in the T group (52.2%) (p = 0.025). The median overall survival (OS) for the L group was 7.0 months, which was significantly longer than that of the T group (p = 0.000). The 3-month and 6-month survival rates were higher in the L group. The adverse events in both groups included abdominal pain, elevated C-reactive protein (CRP) and elevated amylase. The incidence was lower in the L group than in the T group. CONCLUSION: Compared with traditional HIFU treatment, low-power cumulative HIFU treatment showed a significantly higher pain relief rate and survival benefit with a better safety profile in patients with metastatic pancreatic cancer.

Silver nanoparticle-assembled micro-bowl arrays for sensitive SERS detection of pesticide residue.

It is of great significance to develop a simple and effective method for constructing large-scale high-quality surface-enhanced Raman scattering (SERS) substrate. Here, an Ag nanoparticle-assembled micro-bowl array was prepared by a close-packed polystyrene (PS) sphere monolayer templated electrodeposition approach. The fabricated Ag nanoparticle-assembled micro-bowl array shows high SERS sensitivity to rhodamine 6G (R6G) under an ultra-low concentration of 1 fM, and exhibits excellent SERS spectral uniformity with a small relative standard deviation (RSD) of 7.6% and good reproducibility (a RSD ∼8.2% for the average peak intensities from different batches of SERS substrates). The fabricated micro-bowl array SERS substrate was employed to detect pesticide residue (thiram and methyl parathion) on vegetables. The limit of detections (LODs) for the two pesticides are lower than the maximum residue limits (MRLs) set by the European Union respectively, showing promising application in rapid inspection of food safety.

Pain management of pancreatic cancer patients with high-intensity focused ultrasound therapy.

This study was performed to evaluate cancer pain control of high-Intensity focused ultrasound ablation (HIFU) and to manage the HIFU treatment pain in advanced pancreatic cancer patients with analgesics. We collected 71 locally advanced pancreatic cancer patients treated with HIFU from 2013 March to 2014 January in our hospital. The cancer pain (pre-HIFU and two weeks after HIFU) and HIFU treatment pain were evaluated respectively. The numeric rating scale (NRS) was used as the tool of pain evaluation. The related factors with pains were analyzed. The 70.42% cancer painless rate before HIFU was improved to 92.96% (P<0.05) 2 weeks after HIFU in 71 advanced pancreatic cancer patents without analgesics adjustment. The HIFU treatment pain occurred in 42 of 71 treated patients (59.15 %). The average duration was 3.93 days and pain score was 3.22. HIFU can improve cancer pain relief further in the advanced pancreatic cancer patients with third ladder analgesics, meanwhile HIFU treatment pain can be managed easy because of its short duration and low pain score.

A flexible transparent Ag-NC@PE film as a cut-and-paste SERS substrate for rapid in situ detection of organic pollutants.

This report presents a simple and inexpensive fabrication approach to a flexible transparent composite film as a "cut-and-paste" surface-enhanced Raman scattering (SERS) substrate for in situ detection of organic pollutants. First, a self-assembled monolayer of Ag-nanocubes (Ag-NCs) is obtained at the air/water interface. Then, the Ag-NC monolayer is retrieved onto a flexible transparent polyethylene (PE) film to achieve an Ag-NC@PE composite film as a flexible SERS substrate. As the Ag-NCs in the monolayer are closely and uniformly packed on the PE film, the Ag-NC@PE composite film shows high SERS-activity with good signal homogeneity and reproducibility. Furthermore, the flexible transparent Ag-NC@PE composite film is "cut into" small pieces and directly "pasted" onto contaminated fruits for in situ SERS detection, as a result 10 nM thiram, 1 µM 4-polychlorinated biphenyl and 10 nM methyl parathion contaminants on oranges are detected, respectively. Therefore the Ag-NC@PE composite film is an inexpensive and effective SERS substrate for rapid in situ detection of organic pollutants in aqueous solutions, on fruits and other solid objects.

An ordered array of hierarchical spheres for surface-enhanced Raman scattering detection of traces of pesticide.

An ordered array of hierarchically-structured core-nanosphere@space-layer@shell-nanoparticles has been fabricated for surface-enhanced Raman scattering (SERS) detection. To fabricate this hierarchically-structured chip, a long-range ordered array of Au/Ag-nanospheres is first patterned in the nano-bowls on the planar surface of ordered nanoporous anodic titanium oxide template. A ultra-thin alumina middle space-layer is then conformally coated on the Au/Ag-nanospheres, and Ag-nanoparticles are finally deposited on the surface of the alumina space-layer to form an ordered array of Au/Ag-nanosphere@Al2O3-layer@Ag-nanoparticles. Finite-difference time-domain simulation shows that SERS hot spots are created between the neighboring Ag-nanoparticles. The ordered array of hierarchical nanostructures is used as the SERS-substrate for a trial detection of methyl parathion (a pesticide) in water and a limit of detection of 1 nM is reached, indicating its promising potential in rapid monitoring of organic pollutants in aquatic environment.

Ag Nanoparticle-Grafted PAN-Nanohump Array Films with 3D High-Density Hot Spots as Flexible and Reliable SERS Substrates.

A facile fabrication approach of large-scale flexible films is reported, with one surface side consisting of Ag-nanoparticle (Ag-NP) decorated polyacrylonitrile (PAN) nanohump (denoted as Ag-NPs@PAN-nanohump) arrays. This is achieved via molding PAN films with ordered nanohump arrays on one side and then sputtering much smaller Ag-NPs onto each of the PAN-nanohumps. Surface-enhanced Raman scattering (SERS) activity of the Ag-NPs@PAN-nanohump array films can be improved by curving the flexible PAN film with ordered nanohump arrays during the Ag-sputtering process to increase the density of the Ag-NPs on the sidewalls of the PAN-nanohumps. More 3D hot spots are thus achieved on a large-scale. The Ag-NPs@PAN-nanohump array films show high SERS activity with good Raman signal reproducibility for Rhodamine 6G probe molecules. To trial their practical application, the Ag-NPs@PAN-nanohump array films are employed as SERS substrates for trace detection of trinitrotoluene and a congener of polychlorinated biphenyls. A lower detection limit of 10(-12) m and 10(-5) m can be achieved, respectively. Furthermore, the flexible Ag-NPs@PAN-nanohump array films can also be utilized as swabs to probe traces of methyl parathion on the surface of fruits such as apples. The as-fabricated SERS substrates therefore have promising potential for applications in rapid safety inspection and environmental protection.

Influence of high intensity focused ultrasound (HIFU) treatment to the pancreatic function in pancreatic cancer patients.

Present study was designed to investigate the pancreatic endocrine and exocrine function damage after High Intensity Focused Ultrasound (HIFU) therapy in patients with advanced pancreatic cancer. It was a retrospective analysis of blood glucose and amylase changes in 59 advanced pancreatic cancer patients treated with HIFU from 2010 February to 2014 January. The mean glucose and amylase before HIFU treatment were 6.02mmol/L and 59.17 U/L respectively. After HIFU treatment, it was shown that the mean glucose and amylase levels were 5.66mmol/L and 57.86/L respectively. There was no statistical significance between them. No acute pancreatitis was observed. The endocrine and exocrine function of pancreatic cancer patients was not damaged by HIFU treatment. HIFU treatment for the pancreatic cancer patients seems to be safe.

Ordered arrays of Au-nanobowls loaded with Ag-nanoparticles as effective SERS substrates for rapid detection of PCBs.

Large-scale hexagonally close-packed arrays of Au-nanobowls (Au-NBs) with tens of Ag-nanoparticles (Ag-NPs) dispersed in each bowl (denoted as Ag-NPs@Au-NB arrays) are achieved and utilized as effective surface-enhanced Raman scattering (SERS) substrates. The field enhancement benefiting from the special particle-in-cavity geometrical structure as well as the high density of SERS hot spots located in the sub-10 nm gaps between adjacent Ag-NPs and at the particle-cavity junctions all together contribute to the high SERS activity of the Ag-NPs@Au-NB arrays; meanwhile the ordered morphological features of the Ag-NPs@Au-NB arrays guarantee uniformity and reproducibility of the SERS signals. By modifying the Ag-NPs@Au-NB arrays with mono-6-thio-ß-cyclodextrin, the SERS detection sensitivity to 3,3('),4,4(')-tetrachlorobiphenyl (PCB-77, one congener of polychlorinated biphenyls (PCBs, kinds of persistent organic pollutants which represent a global environmental hazard)) can be further improved and a low concentration down to 5 × 10(-7) M can still be examined, showing promising potential for application in rapid detection of trace-level PCBs in the environment.

Initial treatment for surgery-naïve desmoid tumors by high intensity focused ultrasound.

Introduction: Desmoid tumor (DT) is a rare proliferative disease occurring in connective tissues, characterized by high infiltration and recurrence rates. While surgery remains the primary treatment, its recurrence risk is high, and some extra-abdominal desmoid tumors are inoperable due to their locations. Despite attempts with radiotherapy and systemic therapy, the efficacy remains limited. Methods: We used low-power cumulative high-intensity focused ultrasound (HIFU) therapy as an initial treatment for desmoid tumor patients either ineligible or unwilling for surgery. Low-power cumulative HIFU employs slower heat accumulation and diffusion, minimizing damage to surrounding tissues while enhancing efficacy. Results: Fifty-seven non-FAP desmoid tumor patients, previously untreated surgically, underwent low-power cumulative HIFU therapy. Among them, 35 had abdominal wall DT, 20 had extra-abdominal DT, and 2 had intra- abdominal DT, with an 85% median ablation ratio. Abdominal wall DT patients showed significantly better response rates (91.4% vs. 86%) and disease control rates (100% vs. 32%) than that of non-abdominal wall DT patients. Median event- free survival time was not reached after a median follow-up duration of 34 months. Discussion: With its high response rate, durable efficacy, and mild adverse effects, our findings suggest that low-power cumulative HIFU presents a promising novel treatment for desmoid tumors, particularly abdominal wall DT patients.

Biomass-derived lightweight SiC aerogels for superior thermal insulation.

Silicon carbide (SiC) aerogels, which possess unique porous structure and high ablation resistance, show great potential as thermal insulation materials, but their wide application is limited by expensive and cumbersome synthetic procedures. Therefore, it is pivotal to develop a facile, versatile, and cost-effective method for producing SiC aerogels. Herein, we have successfully prepared ultra-light SiC nanowire aerogels (SNWAs) boasting remarkably low thermal conductivity, using biomass-derived carbon templates (BCTs) through a direct carbothermal reduction method. The BCTs obtained by simply carbonizing freeze-dried eggplants can serve not only as the carbon sources but also as the templates for the in situ growth of SiC nanowires. The resultant three-dimensional (3D) SNWAs possess various porous structures, incorporating the original micro-sized pores inherited from the eggplant and nano-sized pores constructed from interconnected SiC nanowires. These multi-scale pore structures bestow SNWAs with lower gas-phase heat conduction characteristics. Besides, the numerous stacking faults and heterojunctions present in the SiC nanowires play a key role in obstructing the solid-phase heat transfer and reinforcing the SiC skeleton. As a result, the SNWAs show an exceptionally low thermal conductivity, measuring 0.0149 W m-1 K-1 at room temperature, and maintain this low value (0.0256 W m-1 K-1) even at 500 °C. Remarkably, even after being exposed to air at 1200 °C for 2 h, the SNWAs maintain a low thermal conductivity of 0.0226 W m-1 K-1. Such low-cost and effective preparation of biomass-derived SiC aerogels is anticipated to pave a new avenue for the development of advanced thermal insulators.

Hydrophobic Microenvironment Modulation of Ru Nanoparticles in Metal-Organic Frameworks for Enhanced Electrocatalytic N2 Reduction.

The modulation of the chemical microenvironment surrounding metal nanoparticles (NPs) is an effective means to enhance the selectivity and activity of catalytic reactions. Herein, a post-synthetic modification strategy is developed to modulate the hydrophobic microenvironment of Ru nanoparticles encapsulated in a metal-organic framework (MOF), MIP-206, namely Ru@MIP-Fx (where x represents perfluoroalkyl chain lengths of 3, 5, 7, 11, and 15), in order to systematically explore the effect of the hydrophobic microenvironment on the electrocatalytic activity. The increase of perfluoroalkyl chain length can gradually enhance the hydrophobicity of the catalyst, which effectively suppresses the competitive hydrogen evolution reaction (HER). Moreover, the electrocatalytic production rate of ammonia and the corresponding Faraday efficiency display a volcano-like pattern with increasing hydrophobicity, with Ru@MIP-F7 showing the highest activity. Theoretical calculations and experiments jointly show that modification of perfluoroalkyl chains of different lengths on MIP-206 modulates the electronic state of Ru nanoparticles and reduces the rate-determining step for the formation of the key intermediate of N2H2 *, leading to superior electrocatalytic performance.

Kirkendall effect induced ultrafine VOOH nanoparticles and their transformation into VO2(M) for energy-efficient smart windows.

Vanadium dioxide (VO2) has received widespread attention for application in energy-efficient smart windows because of its distinct thermochromic property in the near-infrared region during the reversible metal-insulator phase transition. In this study, lepidocrocite VOOH ultrafine nanoparticles (NPs) with a diameter less than 30 nm were prepared by a mild and efficient hydrothermal method, and the Kirkendall effect played a vital role in the growth of the VOOH NPs. It was found that VOOH could be transformed into VO2via a subsequent annealing treatment during which the size and morphology of VOOH are well preserved even though the annealing temperature is up to 500 °C. The ultrafine VO2 NPs are crucial for achieving excellent nanothermochromic performance with a luminous transmittance (Tlum) up to 56.45% and solar modulation ability (ΔTsol) up to 14.95%. The environmental durability is well improved by coating VO2 NPs with an SiO2 shell as confirmed via progressive oxidation and acid corrosion experiments. Meanwhile, the Tlum of the VO2@SiO2 film is further increased from 56.45% to 62.29% while the ΔTsol remained unchanged. This integrated thermochromic performance presents great potential for the development of VO2-based smart windows.

Mitochondrial translocation of cofilin is required for allyl isothiocyanate-mediated cell death via ROCK1/PTEN/PI3K signaling pathway.

BACKGROUND: Cofilin is a member of the actin depolymerizing factor (ADF)/cofilin family, which regulates actin dynamics. Increasing evidence suggests that mitochondrial translocation of cofilin appears necessary for the regulation of apoptosis. RESULTS: We report that allyl isothiocyanate (AITC) potently induces mitochondria injury and apoptosis. These events were accompanied by a loss of polymerized filamentous actin (F-actin) and increase in unpolymerized globular actin (G-actin). AITC also induces dephosphorylation of cofilin through activation of PP1 and PP2A. Only dephosphorylated cofilin binds to G-actin and translocates to mitochondria during AITC-mediated apoptosis. Mechanistic study revealed that interruption of ROCK1/PTEN/PI3K signaling pathway plays a critical role in AITC-mediated dephosphorylation and mitochondrial translocation of cofilin and apoptosis. Our in vivo study also showed that AITC-mediated inhibition of tumor growth of mouse leukemia xenograft model is in association with dephosphorylation of cofilin. CONCLUSIONS: These findings support a model in which induction of apoptosis by AITC stems primarily from activation of ROCK1 and PTEN, and inactivation of PI3K, leading in turn to activation of PP1 and PP2A, resulting in dephosphorylation of cofilin, which binds to G-actin and translocates to mitochondria, culminating in the dysfunction of mitochondria, release of cytochrome c and apoptosis.

New clinical application of high-intensity focused ultrasound: local control of synovial sarcoma.

High-intensity focused ultrasound (HIFU) is playing an increasingly important role in cancer therapy. Primary synovial sarcomas of the chest wall are extremely rare. We report the first case of noninvasive HIFU therapy for the control of synovial sarcoma. A 51-year-old man was diagnosed with spindle cell sarcoma on the left chest wall through lumpectomy. After four cycles of chemotherapy, local recurrence of the sarcoma was detected. Subsequent extended resection confirmed synovial sarcoma. After five cycles of a new chemotherapy option, the sarcoma relapsed again. Then the patient received five courses of HIFU; this completely ablated the sarcoma without complications. No chemotherapy, radiotherapy, or biological therapy has been applied since. Now the patient is stable and has a high quality of life.

Flexible 3D Substrate of Ag Nanoparticle-Loaded Carbon Aerogels with Outstanding Surface-Enhanced Raman Scattering Performance.

Surface-enhanced Raman scattering (SERS), an ultra-sensitive and non-destructive analytic technique, has attracted wide attention from the scientific community. Despite its rapid development, limited hotspots on the SERS substrates have restricted their potential in practical applications. Herein, we developed a facile method to fabricate a flexible three-dimensional (3D) SERS substrate composed of silver nanoparticles (Ag NPs)-loaded carbon aerogels (CAs). Such a flexible Ag NPs/CAs substrate exhibited numerous hotspots, which can facilely be adjusted not only by tuning the density of Ag NPs but also by controlling the bending degree of the flexible substrate. In addition, the influence of hotspots on the local electric field enhancement was investigated by theoretical calculations. Moreover, the 3D network structure of the CAs with a large specific surface area and strong adsorption ability can improve the capture of target molecules. Consequently, the optimal Ag NPs/CAs substrate has a low detection limit of 10-12 M for rhodamine 6G molecules as well as good repeatability. Furthermore, based on the good performance of SERS detection of the Ag NPs/CAs substrate, it can also be practically used for the detection of thiram molecules on the surface of cherry tomatoes. Such a flexible 3D Ag NPs/CAs substrate has great potential for practical environmental monitoring applications.

Large-scale homogeneously distributed Ag-NPs with sub-10 nm gaps assembled on a two-layered honeycomb-like TiO2 film as sensitive and reproducible SERS substrates.

We present a surface-enhanced Raman scattering (SERS) substrate featured by large-scale homogeneously distributed Ag nanoparticles (Ag-NPs) with sub-10 nm gaps assembled on a two-layered honeycomb-like TiO(2) film. The two-layered honeycomb-like TiO(2) film was achieved by a two-step anodization of pure Ti foil, with its upper layer consisting of hexagonally arranged shallow nano-bowls of 160 nm in diameter, and the lower layer consisting of arrays of about fifty vertically aligned sub-20 nm diameter nanopores. The shallow nano-bowls in the upper layer divide the whole TiO(2) film into regularly arranged arrays of uniform hexagonal nano-cells, leading to a similar distribution pattern for the ion-sputtered Ag-NPs in each nano-cell. The lower layer with sub-20 nm diameter nanopores prevents the aggregation of the sputtered Ag-NPs, so that the Ag-NPs can get much closer with gaps in the sub-10 nm range. Therefore, large-scale high-density and quasi-ordered sub-10 nm gaps between the adjacent Ag-NPs were achieved, which ensures homogeneously distributed 'hot spots' over a large area for the SERS effect. Moreover, the honeycomb-like structure can also facilitate the capture of target analyte molecules. As expected, the SERS substrate exhibits an excellent SERS effect with high sensitivity and reproducibility. As an example, the SERS substrate was utilized to detect polychlorinated biphenyls (PCBs, a kind of persistent organic pollutants as global environmental hazard) such as 3,3',4,4'-pentachlorobiphenyl (PCB-77) with concentrations down to 10(-9) M. Therefore the large-scale Ag-NPs with sub-10 nm gaps assembled on the two-layered honeycomb-like TiO (2) film have potentials in SERS-based rapid trace detection of PCBs.