Investigation on the pollution release characteristics of subgrade base materials prepared by oil-based cutting thermal desorption residues.

The preparation of oil-based cutting thermal desorption residues into subgrade materials is one of the methods of their resource utilization. While the environmental safety for subgrade materials is lack of discussions. In this study, through the semi-dynamic leaching tests, the leaching characteristics of pollutants from residues subgrade materials under extremely acidic conditions were simulated. According to Fick's second law, combined with the effective diffusion coefficient (De), the risk of pollutant leaching and release in residue subgrade materials were evaluated. The concentrations of naphthalene, anthracene, benzo(a)anthracene, dibenzo(a,h)anthracene, Cd, and Zn met the requirements of class III water quality in the Chinese standard GB/T14848-2017. The release of naphthalene, anthracene, benzo(a)anthracene, dibenzo(a,h)anthracene, and Cd of leaching was dominated by diffusion. The release of benzo(a)pyrene and Zn of leaching was mainly dissolution. Hence, based on the investigation, the release law and characteristics of pollutants were explored when thermal desorption residues were applied as subgrade materials, which provided an important reference basis for the resource and utilization of oil-based cutting thermal desorption residues.

Dual signal magnification for ultrasensitive biosensing based on well-regulated SERS of AuNTs@AuHg and DSN-assisted amplification.

AuNTs@AuHg alloy with well-regulated SERS properties was proposed, which displayed wonderful SERS intensity and effective salt resistance. Using miRNA-21 as a model analyte and combining with DSN-assisted amplification, a dual signal amplification strategy for ultrasensitive miRNA biosensing with a low detection limit (0.53 fM) and satisfactory selectivity was designed.

Modulating Polarization of Perovskite-Based Heterostructures via In Situ Semiconductor Generation and Enzyme Catalysis for Signal-Switchable Photoelectrochemical Biosensing.

Polarization of photoactive materials in current photoelectric (PE) systems is difficult to be adjusted, and thus electron-transfer routes of these systems are unchangeable, which limits their performance in photoelectrochemical (PEC) analysis. Herein, we attempted to modulate the polarization of perovskite-based heterostructures by both in situ semiconductor generation and enzyme catalysis. Owing to their band alignments, Cs3Bi2Br9 quantum dots (QDs) and BiOBr are confirmed to construct a Z-scheme structure, leading to a large anodic photocurrent. In the presence of ascorbic acid 2-phosphate (AAP), BiPO4 is generated on the surface of the Cs3Bi2Br9 QDs/BiOBr heterostructure, reassigning energy bands of BiOBr. Accordingly, polarization of the photoactive materials is converted, and a new Z-scheme structure with a reversed electron-transfer route is constructed, which leads to an evident cathodic photocurrent. Furthermore, abundant electron donors can be obtained by catalyzing AAP with alkaline phosphatase (ALP). In this case, photogenerated holes in BiOBr are preferentially annihilated by electron donors, thereby blocking transfer of photogenerated electrons in the Cs3Bi2Br9 QDs/BiOBr/BiPO4 heterostructure. Consequently, a second polarization conversion is triggered by enzyme catalysis, resulting in the recovery of an anodic photocurrent. Benefited from the polarization conversion, a PEC biosensor with a feature of two-wing signal switch is designed, which remarkably enlarges the range of the signal response and subsequently improves the analytical performance. As a result, ALP in small volume of human serum can be quantified with this method. In this work, polarization of perovskite-based photoactive materials is tuned, proposing an alternative perspective on the design of advanced PE systems.

A novel activation-hydrochar via hydrothermal carbonization and KOH activation of sewage sludge and coconut shell for biomass wastes: Preparation, characterization and adsorption properties.

A two-stage method of hydrothermal carbonization and chemical activation technology was applied to prepare a novel, large surface area and rich-pore structure activation-hydrochar from sludge sewage and coconut shell due to its mild, low-cost, and well-developed merits. The pore-making mechanism of activation-hydrochar was discussed by FT-IR, XPS, SEM, TG, TG-MS, XRD, and BET characterization. These results illustrated that the first stage of hydrothermal carbonization achieved the rich-pore structure hydrochar via dehydration, decarboxylation, deamination, and rearrangement reactions. The subsequent KOH activation was conducive to the pore-forming process. Specifically, the pore structure of activation-hydrochar was ameliorated and abundant active adsorption sites were obtained by the modification. The adsorption properties of activation-hydrochar on Methylene Blue (MB) and Congo Red (CR) were systematically investigated, and the max adsorption capacities of those were obtained with 623.37 mg/g and 228.25 mg/g, respectively. The pseudo-second-order kinetics and Langmuir models were both fit to elucidate the adsorption process for both dyes. Thermodynamics revealed adsorption performance accompanied by the spontaneous and endothermic processes. In general, the research clearly indicated the synthesis route for activation-hydrochar, and its further adsorption performance, capacity, and mechanism on MB and CR. This research demonstrated that activation-hydrochar with the abundant surface area and rich-pore structure made it a candidate for the production of effective adsorption material. It is prospective to achieve the utilization of wastes and its further application in wastewater treatment.

A versatile switchable dual-modal colorimetric and photoelectrochemical biosensing strategy via light-controlled sway of a signal-output transverter.

A design criterion to construct a versatile dual-modal colorimetric and PEC biosensing platform for switching the corresponding mode freely is proposed via integration of a natural enzyme, light-activated nanozyme and light-controlled swayable signal-output transverter. A switchable dual-modal platform toward DNA analysis is developed as a proof of concept.

Influence of GSTP-1 Polymorphism on the Prognosis of Patients with High-Grade Glioma Who Received Temozolomide Plus Radiotherapy Adjuvant Treatment.

BACKGROUND: Glutathione S-Transferase P 1 (GSTP-1) gene plays an important physiological role in the body. The present study was conducted to identify the clinical implication of GSTP-1 gene polymorphism on the prognosis of patients with high-grade glioma (HGG) who received temozolomide plus radiotherapy adjuvant treatment. METHODS: This study recruited a total of 186 patients with HGG who were treated with temozolomide plus radiotherapy adjuvant regimen (retrospectively). Baseline clinical characteristics were obtained and the prognostic data of the patients were collected. Peripheral blood specimen of patients was preserved for genotyping of GSTP-1 polymorphism during hospitalization. Correlation analysis was carried out accordingly. Additionally, fresh peripheral blood specimens that were available for mRNA expression analysis were collected for the mRNA expression analysis. RESULTS: The median progression-free survival (PFS) and overall survival (OS) of the 186 patients with HGG who received temozolomide plus radiotherapy regimen was 8.5 months (95% CI: 5.95-11.05) and 15.5 months (95% CI: 11.49-19.51), respectively. The prevalence of 313A>G among 186 patients with glioma was AA genotype: 126 cases (67.7%), AG genotype: 54 cases (29.1%), GG genotype: 6 cases (3.2%), minor allele frequency of 313A>G was 0.18. Association analysis suggested that the median PFS of patients with AA and AG/GG genotypes was 11.2 and 5.0 months, respectively (χ2=11.17, P=0.001). Furthermore, the median OS of patients with AA and AG/GG genotypes was 18.9 and 10.5 months, respectively (χ2=12.684, P<0.001). Besides, when adjusted for PFS in multivariate Cox regression analysis, AG/GG genotype was an independent factor for PFS (HR=0.48, P=0.006). The mRNA expression results indicated that mRNA expression of GSTP-1 in patients with AG/GG genotypes of 313A>G was significantly higher than that of patients with AA genotype (P<0.001). CONCLUSION: GSTP-1 polymorphism 313A>G might be used as a potential biomarker to predict the prognosis of patients with HGG who received temozolomide plus radiotherapy adjuvant treatment.

Formation of a Photoelectrochemical Z-Scheme Structure with Inorganic/Organic Hybrid Materials for Evaluation of Receptor Protein Expression on the Membrane of Cancer Cells.

Quantitative analysis of receptor protein expression is essential to give new insights into tumor-related research. Benefitting from their high sensitivity and low background, photoelectrochemical (PEC) platforms are considered as powerful tools for evaluating the expression of receptor proteins. Herein, to reduce the cytotoxicity and facilitate the subsequent assembly, l-cysteine-modified Ag-ZnIn2S4 quantum dots (l-Cys AZIS QDs) are prepared and PEC responses under the irradiation of long wavelength light are obtained. To further improve the PEC behavior, iron phthalocyanine (FePc) is employed to form a Z-scheme structure with l-Cys AZIS QDs. The Z-scheme structure based on l-Cys AZIS QDs/FePc hybrid materials exhibits high photo-to-electric conversion efficiency and can be excited with near-infrared range light. Because hyaluronic acid linked to photoactive materials can recognize CD44 expressed on the membrane of cancer cells, cancer cells are immobilized onto l-Cys AZIS QDs/FePc hybrid materials, inducing a decrease of the photocurrent intensity. Consequently, a PEC cytosensor is constructed to quantify cancer cells expressing CD44. The PEC analytical platform is able to determine A549 cells in the range of 2 × 102 to 4.5 × 106 cells/mL, and a detection limit of 15 cells/mL is realized in the case of S/N = 3. In addition, the expression of CD44 in A549 and other five cancer cells is measured with this PEC method. Depending on our data, the expression of CD44 in different cancer cells is distinct, indicating great potential of this method in receptor protein-related studies.

Triple-Helix Molecular Switch Electrochemiluminescence Nanoamplifier Based on a S-Doped Lu2O3/Ag2S Pair for Sensitive MicroRNA Detection.

Development of sensitive detection methods for microRNAs has realistic application value for early clinical analysis and accurate diagnosis. In this study, a triple-helix molecular switch electrochemiluminescence resonance energy transfer (ECL-RET) nanoamplifier was designed to construct an electrochemiluminescence (ECL) biosensor for microRNA determination. The newly synthesized S-doped Lu2O3, which shows a 3 times better ECL performance than Lu2O3, was chosen as the donor in this ECL-RET system. Accordingly, Ag2S quantum dots (QDs) were used as the matched acceptor. They exhibited overlapping spectra and efficient energy transfer between each other. Furthermore, using a triple-helix switch structure with an improved quenching effect for signal amplification and a nano-DNA walker transformational system as a powerful method for target amplification, a supernanoamplifier was achieved. As a consequence, the proposed ECL biosensor for microRNA-141 detection exhibited good analytical performance with a low detection limit (16 aM). The sensor not only led to the development of a novel ECL-RET pair but also provided a strong nanoamplifier for biosensing platform construction, which may offer some new considerations regarding material design, signal amplification, and show promising application value in biomedical and clinical diagnosis.

Integrated miRNA profiling and bioinformatics analyses reveal upregulated miRNAs in gastric cancer.

Gastric cancer is one of the most common malignancies in China and exhibits a poor prognosis. The most significant challenge for gastric cancer treatment is the absence of early diagnostic biomarkers. MicroRNAs (miRNAs) are small non-coding RNAs, which possess clinical value in a number of different types of cancer. The current study identified 13 miRNAs (hsa-miR-22, hsa-miR-545, hsa-let-7i, hsa-miR-15b, hsa-miR-221, hsa-miR-196a, hsa-miR-20a, hsa-miR-196b, hsa-miR-93, hsa-miR-19a, hsa-miR-503, hsa-miR-106b and hsa-miR-18a) that were significantly overexpressed in GC, by analyzing 1,000 GC samples included in four public datasets, including GSE23739, GSE78091, GSE30070 and The Cancer Genome Atlas. Furthermore, it was revealed that the expression levels of these 13 miRNAs were significantly higher in gastric cancer tissues of grades I, II and III compared with normal controls. Gene ontology analysis and Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that the differentially expressed miRNAs were involved in regulating transcription, protein amino acid phosphorylation, signal transduction, protein binding, zinc ion binding, the mitogen-activated protein kinase signaling pathway and focal adhesion. In summary, the present study may provide potential new therapeutic and prognostic targets for gastric cancer.

Red light-driven photoelectrochemical biosensing for ultrasensitive and scatheless assay of tumor cells based on hypotoxic AgInS2 nanoparticles.

A novel red light-driven photoelectrochemical (PEC) biosensing platform based on hypotoxic ternary mercaptopropionic acid (MPA)-capped AgInS2 nanoparticles (NPs) with excellent hydrophily and biocompatibility was proposed. AgInS2 NPs as a PEC sensing substrate exhibited high photon-to-current conversion efficiency under red light excitation, generating an intensive photocurrent for enhancing the sensitivity of PEC determination. After the introduction of the amino-terminated sgc8c aptamer onto the interface of AgInS2 NPs, the overexpressed protein tyrosine kinase-7 on the surface of lymphoblast CCRF-CEM cells could be efficiently captured. Using CCRF-CEM cell as a model analyte, an ultrasensitive PEC biosensor for scatheless assay of cells at the applied potential of 0.15 V under a red light excitation of 630 nm was designed based on the significant decline of photocurrent intensity after capturing CCRF-CEM cells. The developed PEC cytosensor demonstrated an excellent cell-capture ability, as well as a wide linear range from 1.5 × 102 to 3.0 × 105 cells/mL and a low detection limit of 16 cells/mL for CCRF-CEM cells. In addition, the resulting assay method verified high selectivity and negligible cytotoxicity for cells assay. This work provided an alternative method for scatheless assay of tumor cells, which would have promising prospect in clinical diagnoses of cancer.

Evaluation of activated carbon synthesized by one-stage and two-stage co-pyrolysis from sludge and coconut shell.

Waste biomass and sewage sludge were used to obtain an adsorbent material with excellent performance qualities by adopting a KOH activation process via one-stage (ACone) or two-stage (ACtwo) co-pyrolysis. The main purpose of this work was to investigate the effects of both methods in terms of the physicochemical properties and adsorption capacities for methylene blue (MB). Textural analyses revealed that the surface area (Stot= 683.82 m2/g) and total pore volume (Vtot= 0.72 cm3/g) of ACtwo were more than two-fold compared with ACone (Stot= 285.33 m2/g; Vtot= 0.35 cm3/g). Thus, two-stage co-pyrolysis produced activated carbon with increased porosity, which was favorable for MB adsorption. Nevertheless, the intensity of the surface functional groups of ACtwo was weaker than for ACone, which could be due to the pore-forming mechanism. Two-stage co-pyrolysis increased the yield and aromaticity of activated carbon, but sufficient activation caused more functional groups to decompose. For the adsorbate MB, the maximum adsorption capacity of ACtwo (602.80 mg/g) was more than five-fold greater than that of ACone (101.88 mg/g), due to its excellent porosity properties. Furthermore, the interactions of MB molecules with activated carbon were via hydrogen bonds and electrostatic attraction. The adsorption process of MB onto activated carbon was accurately described by the pseudo-second-order kinetic model. Adsorption equilibrium evaluated Langmuir isotherms demonstrated that MB formed a monolayer by adsorption onto the activated carbon. Adsorption thermodynamics was used to investigate the influence of temperature on the adsorption process. Thermodynamic parameters indicated that MB adsorption onto activated carbon was spontaneous and endothermic. In conclusion, our results showed that two-stage co-pyrolysis improves the adsorption capabilities of activated carbon, so achieving better economic value from waste materials.

Green light excited ultrasensitive photoelectrochemical biosensing for microRNA at a low applied potential based on the dual role of Au NPs in TiO2 nanorods/Au NPs composites.

An ultrasensitive photoelectrochemical biosensing strategy for microRNA at a low applied potential was designed based on the robust photocurrent generated by TiO2 nanorods/Au nanoparticles (Au NPs) composites under green light excitation. The dual role of Au NPs dramatically improved the photocurrent, which guaranteed enough sensitivity, leading to the excellent performance in microRNA detection.

Near-Infrared Light Excited and Localized Surface Plasmon Resonance-Enhanced Photoelectrochemical Biosensing Platform for Cell Analysis.

Under near-infrared (NIR) light of 810 nm wavelength for irradiation, a very simple and highly sensitive photoelectrochemical (PEC) biosensing platform has been established using the localized surface plasmon resonance effect of Au nanoparticles (NPs) as signal amplification for the nondestructive analysis of living cells. The water-dispersible Ag2S quantum dots (QDs) synthesized by a one pot method were employed as photoelectrochemically active species, and they exhibited excellent PEC properties irradiated with NIR light which was chosen due to the obvious absorption and fluorescent emission in the NIR light region. After the incorporation of Au NPs on the Ag2S QDs modified ITO electrode, the photoelectric conversion efficiency was greatly increased, at ∼2.5 times that of the pure Ag2S QDs modified electrode. Additionally, 4-mercaptophenylboronic acid (MPBA) molecules, as recognition elements, self-assembled on the electrode surface through Au-S bonds. On the basis of the chemical reaction between sialic acid on the cytomembranes and boric acid of MPBA, the very simple PEC biosensing platform was used for the quantitative determination of MCF-7 cells and dynamic evaluation of cell surface glycan expression under the external stimulus of sialidase. Under NIR light of 810 nm and a potential of 0.15 V, this proposed strategy exhibited a wide linear range from 1 × 102 to 1 × 107 cells/mL, with an experimental detection limit of 100 cells/mL. Importantly, this work provided a promising application for NIR Ag2S QDs coupled with Au NPs in the development of a novel PEC biosensing platform for the nondestructive analysis of biological samples.

An ultrasensitive photoelectrochemical bioanalysis strategy for tumor markers based on the significantly enhanced signal of a bismuth oxyiodine microsphere/graphitic carbon nitride composite.

An innovative and ultrasensitive photoelectrochemical bioanalysis strategy was designed, which provided a promising method for the assay of tumor markers. The BiOI/g-C3N4 composite acted as photoelectrochemical biosensing substrate for significant signal enhancement, and CuS NPs were introduced to label signal antibodies to amplify the signal variation.

A "Signal On" Photoelectrochemical Biosensor Based on Bismuth@N,O-Codoped-Carbon Core-Shell Nanohybrids for Ultrasensitive Detection of Telomerase in HeLa Cells.

Core-shell nanohybrids (NHs) with good semiconducting properties are vital to promote optoelectronic, photocatalytic, biosensing and bioelectronics technologies. Although great process has been achieved, synthesis of NHs composed of semiconductor core and heteroatom-doped nanocarbon shell remains a challenge, and their applications in photoelectronchemical (PEC) biosensors have not been explored. Herein, the synthesis and properties of a Bi nanocrystal and N,O-codoped carbon (NOC) core-shell NHs (Bi@NOC) is described, which exhibits the typical semiconducting feature with the bandgap of 1.14 eV. Also, such NHs show good biocompatibility and their surfaces bear the carboxylic groups that facilitate further assembly of an amino-modified primer DNA. By taking advantage of the excellent PEC activity of Bi@NOC NHs and the signal amplification effect of thioflavine-T, a novel "signal on" PEC aptasensor for the detection of telomerase activity is constructed. The fabricated aptasensor can detect telomerase activity from 5.0×102 to 1.0×106 HeLa cells with a low detection limit of 60 cells. Also, the aptasensor shows a wide linear response ranges, high sensitivity and good reproducibility. This work not only enriches current core-shell NHs family but also offers a novel PEC biosensing platform for detecting telomerase activity that is helpful for early clinical diagnosis of cancer.

Photoelectrochemical Bioanalysis Platform for Cells Monitoring Based on Dual Signal Amplification Using in Situ Generation of Electron Acceptor Coupled with Heterojunction.

By using in situ generation of electron acceptor coupled with heterojunction as dual signal amplification, a simple photoelectrochemical (PEC) bioanalysis platform was designed. The synergic effect between the photoelectrochemical (PEC) activities of carbon nitride (C3N4) nanosheets and PbS quantum dots (QDs) achieved almost nine-fold photocurrent intensity increment compared with the C3N4 alone. After the G-quadruplex/hemin/Pt nanoparticles (NPs) with catalase-like activity toward H2O2 were introduced, oxygen was in situ generated and acted as electron donor by improving charge separation efficiency and further enhancing photocurrent response. The dually amplified signal made enough sensitivity for monitoring H2O2 released from live cells. The photocathode was prepared by the stepwise assembly of C3N4 nanosheets and PbS QDs on indium tin oxide (ITO) electrode, which was characterized by scanning electron microscope. A signal-on protocol was achieved for H2O2 detection in vitro due to the relevance of photocurrent on the concentration of H2O2. Under the optimized condition, the fabricated PEC bioanalysis platform exhibited a linear range of 10-7000 µM with a detection limit of 1.05 µM at S/N of 3. Besides, the bioanalysis platform displayed good selectivity against other reductive biological species. By using HepG2 cells as a model, a dual signal amplifying PEC bioanalysis platform for monitoring cells was developed. The bioanalysis platform was successfully applied to the detection of H2O2 release from live cells, which provided a novel method for cells monitoring and would have prospect in clinical assay.

A localized surface plasmon resonance-enhanced photoelectrochemical biosensing strategy for highly sensitive and scatheless cell assay under red light excitation.

In this work, a novel photoelectrochemical biosensing strategy was designed for cell assay under 630 nm (red light) excitation. WS2/Au NP nanocomposites were prepared as a photoelectrochemical biosensing substrate. The localized surface plasmon resonance effect of Au NPs tremendously improved the photoelectric conversion efficiency and enhanced the detection sensitivity.

Dual Signal Amplification Using Gold Nanoparticles-Enhanced Zinc Selenide Nanoflakes and P19 Protein for Ultrasensitive Photoelectrochemical Biosensing of MicroRNA in Cell.

Using Au nanoparticles (NPs)-decorated, water-soluble, ZnSe-COOH nanoflakes (NFs), an ultrasensitive photoelectrochemical (PEC) biosensing strategy based on the dual signal amplification was proposed. As a result of the localized surface plasmon resonance (SPR) of Au NPs, the ultraviolet-visible absorption spectrum of Au NPs overlapped with emission spectrum of ZnSe-COOH NFs, which generated efficient resonant energy transfer (RET) between ZnSe-COOH NFs and Au NPs. The RET improved photoelectric conversion efficiency of ZnSe-COOH NFs and significantly amplified PEC signal. Taking advantage of the specificity and high affinity of p19 protein for 21-23 bp double-stranded RNA, p19 protein was introduced. P19 protein could generate remarkable steric hindrance, which blocked interfacial electron transfer and impeded the access of the ascorbic acid to electrode surface for scavenging holes. This led to the dramatic decrease of photocurrent intensity and the amplification of PEC signal change versus concentration change of target. Using microRNA (miRNA)-122a as a model analyte, an ultrasensitive signal-off PEC biosensor for miRNA detection was developed under 405 nm irradiation at -0.30 V. Owing to RET and remarkable steric hindrance of p19 protein as dual signal amplification, the proposed strategy exhibited a wide linear range from 350 fM to 5 nM, with a low detection limit of 153 fM. It has been successfully applied to analyze the level of miRNA-122a in HeLa cell, which would have promising prospects for early diagnosis of tumor.

Label-free photoelectrochemical cytosensing via resonance energy transfer using gold nanoparticle-enhanced carbon dots.

A universal and label-free photoelectrochemical cytosensing strategy was designed based on resonance energy transfer (RET) between carbon dots and cysteamine capped gold nanoparticles. RET promoted photo-to-current conversion efficiency and enhanced detection sensitivity. This proposed photoelectrochemical cytosensing platform exhibited a good performance for the assay of tumor cells with overexpressed receptors on cells.

Highly sensitive "signal-on" electrochemiluminescent biosensor for the detection of DNA based on dual quenching and strand displacement reaction.

A "signal-on" electrochemiluminescent DNA biosensing platform was proposed based on the dual quenching and strand displacement reaction. This novel "signal-on" detection strategy revealed its sensitivity in achieving a detection limit of 2.4 aM and its selectivity in distinguishing single nucleotide polymorphism of target DNA.