Two-dimensional graphite-like carbon nitride nanosheets (g-C3N4 NSs) were hybridized with gold nanoparticles (Au NPs) to construct an electrochemiluminescence (ECL) immunosensor. The prepared Au ...NP-functionalized g-C3N4 NS nanohybrids (Au-g-C3N4 NHs) exhibit strong and stable cathodic ECL activity compared to g-C3N4 NSs due to the important roles of Au NPs in trapping and storing the electrons from the conduction band of g-C3N4 NSs, as well as preventing high energy electron-induced passivation of g-C3N4 NSs. On the basis of the improved ECL stability and ECL peak intensity of the Au-g-C3N4 NHs, a novel ECL immunosensor was developed to detect carcinoembryonic antigen (CEA) as a model target analyte. The ECL immunosensor has a sensitive response to CEA in a linear range of 0.02–80 ng mL–1 with a detection limit of 6.8 pg mL–1. Additionally, the proposed immunosensor shows high specificity, good reproducibility, and long-term stability.
Various beneficial properties of graphitic carbon nitride (g‐CN) have been discovered during the promotion of its visible‐light‐driven photocatalytic activity for water splitting. These properties ...enable g‐CN working as a sensing signal transducer with multiple output modes. In this review, state‐of‐the‐art sensing applications of tailored g‐CN nanostructures in the recent years are presented. Initially, g‐CN nanoarchitectures featuring large surface areas, abundance of active sites, and high dispersity in water are presented along with their preparation methods. Then, sensing applications of these g‐CN nanoarchitectures are described in sequence of the immobilization of recognition elements; semiconductor and electron donating properties derive signaling transduction modes, and efficient approaches for improving sensing performances. The review is concluded with a summary and some perspectives on the challenges and future possibilities of this research field.
The fabrication, sensing application, and future perspectives of a graphitic carbon nitride (g‐CN)‐based sensor are highlighted, which includes the following: the design and synthesis of g‐CN nanoarchitectures that are suitable for sensor construction; the strategy of conjugation of recognition elements to g‐CN nanoarchitectures, signaling transduction modes derived from g‐CN's semiconductor and electron donating properties; and efficient approaches for improving sensing performances, i.e., with high sensitivity, specificity, and reproducibility.
Electrochemiluminescence of the luminol–O2 system in an electrolyte-free N,N-dimethylformamide (DMF)–dipropylamine (DPA) cosolution is induced by the formation of a carbamate ionic liquid (IL) from ...the reaction between CO2 and DPA, on the basis of which a facile ECL sensor for measuring atmospheric CO2 has been developed. This ECL sensing method shows several advantages in the detection of CO2, such as high safety, high selectivity, wide linear response range, and good sensitivity. The gas sensor was found to have a linear response range from 100 ppm to 100 v/v% and a detection limit of 80 ppm (at signal-to-noise ratio of 3). This is the first reported IL-induced ECL sensor for a gas, thus the principle of this type of sensor and the IL-induced ECL mechanism have been demonstrated in detail.
Tens of thousands of chimeric RNAs have been reported. Most of them contain a short homologous sequence (SHS) at the joining site of the two partner genes but are not associated with a fusion gene. ...We hypothesize that many of these chimeras may be technical artifacts derived from SHS-caused mis-priming in reverse transcription (RT) or polymerase chain reactions (PCR). We cloned six chimeric complementary DNAs (cDNAs) formed by human mitochondrial (mt) 16S rRNA sequences at an SHS, which were similar to several expression sequence tags (ESTs).These chimeras, which could not be detected with cDNA protection assay, were likely formed because some regions of the 16S rRNA are reversely complementary to another region to form an SHS, which allows the downstream sequence to loop back and anneal at the SHS to prime the synthesis of its complementary strand, yielding a palindromic sequence that can form a hairpin-like structure.We identified a 16S rRNA that ended at the 4th nucleotide(nt) of the mt-tRNA-leu was dominant and thus should be the wild type. We also cloned a mouse Bcl2-Nek9 chimeric cDNA that contained a 5-nt unmatchable sequence between the two partners, contained two copies of the reverse primer in the same direction but did not contain the forward primer, making it unclear how this Bcl2-Nek9 was formed and amplified. Moreover, a cDNA was amplified because one primer has 4 nts matched to the template, suggesting that there may be many more artificial cDNAs than we have realized, because the nuclear and mt genomes have many more 4-nt than 5-nt or longer homologues. Altogether, the chimeric cDNAs we cloned are good examples suggesting that many cDNAs may be artifacts due to SHS-caused mis-priming and thus greater caution should be taken when new sequence is obtained from a technique involving DNA polymerization.
Tens of thousands of chimeric RNAs, i.e., RNAs with sequences of two genes, have been identified in human cells. Most of them are formed by two neighboring genes on the same chromosome and are ...considered to be derived via transcriptional readthrough, but a true readthrough event still awaits more evidence and
-splicing that joins two transcripts together remains as a possible mechanism. We regard those genomic loci that are transcriptionally read through as unannotated genes, because their transcriptional and posttranscriptional regulations are the same as those of already-annotated genes, including fusion genes formed due to genetic alterations. Therefore, readthrough RNAs and fusion-gene-derived RNAs are not chimeras. Only those two-gene RNAs formed at the RNA level, likely via
-splicing, without corresponding genes as genomic parents, should be regarded as authentic chimeric RNAs. However, since in human cells, procedural and mechanistic details of
-splicing have never been disclosed, we doubt the existence of
-splicing. Therefore, there are probably no authentic chimeras in humans, after readthrough and fusion-gene derived RNAs are all put back into the group of ordinary RNAs. Therefore, it should be further determined whether in human cells all two-neighboring-gene RNAs are derived from transcriptional readthrough and whether
-splicing truly exists.
The inability of small molecule drugs to diffuse into tumor interstitium is responsible for the relatively low effectiveness of chemotherapy. Herein, a hydrogen sulfide (H
2
S) gas–involved ...chemosensitization strategy is proposed for pancreatic cancer treatment by developing a tumor-specific lipase-responsive nanomedicine based on aptamer-conjugated DATS/Dox co-loaded PCL-
b
-PEO micelle (DA/D@Ms-A). After receptor-mediated endocytosis and subsequent digestion of PCL blocks by intracellular lipase, the nanomedicine releases Dox and DATS, which then react with intracellular glutathione to produce H
2
S. The cytotoxicity result indicates that H
2
S can enhance Dox chemotherapy efficiency owing to the synergetic therapeutic effect of Dox and H
2
S. Moreover, the nanomedicine is featured with well tumor penetration capability benefitting from the targeting ability of aptamers and high
in vivo
biocompatibility due to the high density of PEO and biodegradable PCL. The nanomedicine capable of synergetic gas-chemotherapy holds great potential for pancreatic cancer treatment.
A rapid, simple, and practical method for the determination of four of the most used thyreostatic drugs (methimazole, 2‐thiouracil, 6‐methyl‐2‐thiouracil, and 6‐propyl‐2‐thiouracil) using CE coupled ...to electrochemiluminescence detection has been established, based on the electrochemiluminescence enhancement of tris(2,2‐bipyridyl)ruthenium(II) with these analytes. Parameters that affect separation and detection were optimized. Under the optimum experimental conditions, the four analytes could be well separated within 11 min at the separation voltage of 16 kV in a running solution containing 20 mM phosphate buffer (pH 9.0) and 1.0 × 10⁻⁴ M Ru(bpy)₃ ²⁺, with a solution of 20 mM phosphate buffer (pH 12.0) containing 1.0 × 10⁻⁴ M Ru(bpy)₃ ²⁺ in the electrochemiluminescence detection cell. The detection limits for methimazole, 6‐methyl‐2‐thiouracil, 6‐propyl‐2‐thiouracil, and 2‐thiouracil were 0.1, 0.05, 0.05, and 0.01 μM, respectively. The proposed method was applied to analyze these drugs in spiked animal feed samples. The recoveries were 88.2∼99.0 and 86.4∼98.7% for the intraday and interday analyses, respectively. The RSDs were 2.7∼4.8 and 1.8∼5.0% for the intraday and interday analyses, respectively. The results demonstrate that the proposed method has promising applications in the detection of thyreostatic drugs in animal feeds.
Gas-involving cancer theranostics have attracted considerable attention in recent years due to their high therapeutic efficacy and biosafety. We have reviewed the recent significant advances in the ...development of stimuli-responsive gas releasing molecules (GRMs) and gas nanogenerators for cancer bioimaging, targeted and controlled gas therapy, and gas-sensitized synergistic therapy. We have focused on gases with known anticancer effects, such as oxygen (O2), carbon monoxide (CO), nitric oxide (NO), hydrogen sulfide (H2S), hydrogen (H2), sulfur dioxide (SO2), carbon dioxide (CO2), and heavy gases that act via the gas-generating process. The GRMs and gas nanogenerators for each gas have been described in terms of the stimulation method, followed by their applications in ultrasound and multimodal imaging, and finally their primary and synergistic actions with other cancer therapeutic modalities. The current challenges and future possibilities of gas therapy and imaging vis-à-vis clinical translation have also been discussed.
Uric acid (UA) deposition in human body is very harmful, since it may induce gout. Therefore, it would be of great significance to catalyze the degradation of UA in human body. Herein, platinum ...nanoparticles (PtNPs) were found to be an effective mimic of uricase in the oxidation of UA. PtNPs could lower the activation energy of UA oxidation (i.e., from 139.49 kJ mol(-1) to 61.73 kJ mol(-1)), and thus increase the reaction rate constant dramatically (e.g., by the catalysis of 2.63 mg L(-1) PtNPs, the reaction rate constant of UA degradation at 37 °C was 5.85 × 10(-4) s(-1), which was almost 29000 times higher than that of without PtNPs (2.02 × 10(-8) s(-1))). Effects of degradation conditions, such as the concentration and size of PtNPs, concentration of dissolved oxygen and pH value of the solution on the catalytic degradation of UA have been studied. Furthermore, products of UA degradation were analyzed by GC-MS spectroscopy and FT-IR spectrometry. On this basis, a detailed mechanism was finally proposed for the PtNPs-catalyzed UA degradation.
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