CHINESE JOURNAL OF CATALYSIS
·
2022
·
IF 12.92
Ya Li,Zhenkang Wang,Haoqing Ji,Lifang Zhang,Tao Qian,Chenglin Yan,Jianmei Lu
As an essential raw material for fertilizer production and promising green fuels, ammonia is significant to the national economy and social development. Recently, nitrogen reduction reaction (NRR) towards ammonia under mild conditions has received intensive attention due to environmental friendliness and low energy consumption, compared to the rigorous and contaminative Haber-Bosch process. However, as current research deepens, some fatal challenges emerged in this field–not only high volatility and low repeatability but false–positive results, casting serious doubts about its prospects. In this review, we summarized and discussed some potential factors that possibly induce false-positive results for accurate ammonia quantification, including the aspects of catalyst materials, experimental process, and quantification methods. And corresponding methods to eliminate these effects are also summarized. Furthermore, a promising protocol and several control principles are proposed to eliminate potential errors during ammonia quantification. This review establishes a paradigm base in NRR research field toward more accurate ammonia quantification.
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
International Journal of Analytical Chemistry
·
2020
·
IF 1.678
Lina Huang,Hanke Li,Yuhang Li,Peng Ren,Lezhou Yi,Yang Chen,Tongmei Ma
Background. Organic tin compounds (OTCs), a group of high-risk hazardous substances, are highly concerned in safety regulation of consumer products especially for toys because they can cause serious damage to organs after prolonged or repeated exposure. Gastric juice migration is nowadays widely implemented to assess organic tin intake from toys or food-contact materials; however, the followed up detection method using sodium tetraethylborate [NaB(Et4)] as a derivatization agent may directly lead to false positive of monomethyltins (MMT). Objective. In order to avoid the phenomena of false positive of MMT in the course of laboratory testing of toys, it is necessary and important to perform relative experimental and theoretical studies to reveal the cause of false positive of MMT. Method. With metal tin powder as a representative of inorganic tin which existed in real samples, it was treated with artificial gastric juice (0.07 mol/L·HCl), followed by ethyl derivatization using sodium tetraethylborate [NaB(Et)4] and then analyzed by gas chromatography-mass spectrometry (GC-MS) according to the procedure specified in the standard of EN 71-3:2013+A3:2018 issued by the European Committee for Standardization (CEN). Results. Without any OTCs in the starting materials, MMT false positive can be reproduced by detecting 0.56 mg/L of triethylmethyltin (TEMT) together with approximately 1000 mg/L of tetraethyltin (TeET), which is similar to real samples. Further, it is demonstrated that the detected amount of TEMT is linearly related with the added amount of NaB(Et)4, and that the formation of TEMT (methyl derivative) is easier than TeET (ethyl derivative) even though the ethyl group is present in a larger amount than the methyl group. Conclusions. The phenomena of MMT false positive which occurred in the laboratory testing of toys is mainly because that TEMT is highly likely to be obtained from the reaction of inorganic tin and trace level of methylation agent impurities contained in the derivatization reagent—NaB(Et)4. To avoid MMT false positive, it is concluded that the maximum acceptable mole ratio of methylation agent impurities contained in NaB(Et)4 is approximately 0.028%. This research is helpful to be aware of methylation impurities and is favorable to avoid false judgment caused by MMT false positive in routine analysis of toys.
研究领域:
分析化学
·
毒理学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Yu Liu,Wen-Yan Jiang,Yuying Liao,Ruikun Sun,Jiale Hu,Zifan Lu,Min Chang,Jie Yang,Zhenqing Dai,Chunxia Zhou,Pengzhi Hong,Zhong-Ji Qian,Shengli Sun,Lei Ren,Yan-Qiu Liang,Yueqin Zhang,Chengyong Li
In the field of microplastics research, more accurate standardised methods and analytical techniques still need to be explored. In this study, a new method for the microplastics quantitatively and qualitatively analysis by two-phase (ethyl acetate-water) system combined with confocal Raman spectroscopy was developed. Microplastics can be separated from false-positive microplastics in beach sand and marine sediment , attributing to the hydrophobic-lipophilic interaction (HLI) of the two-phase system. Results show that the recovery rates of complex environment microplastics (polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide 66 (PA 66), polycarbonate (PC) and polyethylene (PE)) are higher than 92.98%. Moreover, the new technique can also be used to detect hydrophobic and lipophilic antibiotics, such as sulfamethoxazole (SMX), erythromycin (EM), madimycin (MD), and josamycin (JOS), which adsorbed on microplastics and are extracted based on the dissolving-precipitating mechanism. This innovative research strategy provides a new scope for further detection of marine environment microplastics and toxic compounds adsorbed on its surface.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
·
2024
·
IF 1.2
Liyi Ma,Lixuan Mu,Lushan Huang,Guangwei She,Wensheng Shi
An outstanding fluorescent probe for adenosine 5′-triphosphate (ATP) in the millimolar range will shed deep light on the physiological role of ATP. Many fluorescent probes based on rhodamine spirolactam derivatives have been developed for this purpose and claimed to detect millimolar ATP excellently, where ATP or adenosine 5′-triphosphate disodium salt (ATP-2Na) dissolved in a buffer solution is employed to examine their response to ATP. However, in this work, it was found that both millimolar ATP and ATP-2Na could significantly decrease the pH of the common buffer solution even for several units. Considering the dependence of the rhodamine spirolactam fluorescence on pH, a series of rhodamine spirolactam-based probes was synthesized to investigate their fluorescence response to pH and ATP-2Na. The results demonstrated that the fluorescence response of the probes to millimolar ATP-2Na indeed resulted from both ATP-2Na itself and the pH decrease induced by ATP-2Na. Furthermore, it was evidenced that acidic pH was crucial for the probes to produce fluorescence response to millimolar ATP-2Na itself, and the rhodamine spirolactam-based probes would show poor sensitivity to millimolar ATP-2Na at near-natural pH. Accordingly, the previous conclusion that the rhodamine spirolactam-based probes could detect millimolar ATP excellently was almost erroneous, and might mislead the design and practice of intracellular ATP probe in the future. This work notes that attention should be paid to the physiochemical properties of the analyte and the environmental changes produced by the target analyte.
研究领域:
分析化学
·
生物化学
·
分子生物学
·
荧光光谱学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Xuemeng Li,Jinxiu Wei,Kai Zhu,Yuanyuan Liu,Lei Wu,Kuo Yang,Shenfei Zong,Zhuyuan Wang,Yiping Cui
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) caused the global pandemic known as coronavirus disease 2019 (COVID-19). Accurate screening of SARS-CoV-2 is crucial in controlling the spread of the virus. Moreover, the false positive diagnosis will cause significant waste of the medical resources. Hence, we introduce a s uper- r esolution d ual f luorescence c o-localization (SR-DFC) strategy for the detection of SARS-CoV-2, which can greatly reduce false positive rates. In the SR-DFC assay, fluorescent capture probes are first modified onto periodically structured gold array substrates to capture the spike protein of SARS-CoV-2. Then, fluorescent recognition probes are added to identify SARS-CoV-2, forming sandwich-like immune complex structures. SR-DFC is realized by utilizing single-molecule localization microscopy (SMLM). Specific recognition of SARS-CoV-2 will induce high fluorescence colocalization between the capture probes and recognition probes. Owing to the high spatial resolution of SMLM, nonspecific adsorption can be well excluded, which greatly improves the specificity and significantly reduces false positive rates. Using a pixel counting method proposed by our group, quantitative detection of SARS-CoV-2 could be realized. The detection range covered in this study is between 0.1 ng/mL to 1000 ng/mL. By simply changing capture probes and recognition probes, the SR-DFC strategy is feasible for the detection of other targets, indicating a good universality. Such a highly accurate sensing strategy holds promising potential in the screening of infectious diseases.
研究领域:
病毒学
·
医学诊断
·
显微镜技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2025
·
IF 4.3
Hanhua Li,Jiale Gao,Huiwen Xiong,Dilimulati Yishake,Lin Liu,Jilie Kong,Qin Chen,Xueen Fang,Wenhao Weng
Loop-mediated isothermal amplification (LAMP) holds great promise for rapid nucleic acid detection. However, its application is hindered by the notable occurrence of false positives. In this work, gold nanorod (AuNR)-mediated hot start effect, which adsorbs primers and controls the release of single-stranded DNA (ssDNA) primers at about 50 °C, was demonstrated. The AuNR-mediated LAMP reaction for detecting African horse sickness virus (AHSV) showed high selectivity against other DNA fragments, even at high magnesium concentrations. Furthermore, the assay achieves excellent sensitivity with a detection limit of 100 copies/μL. Additionally, the method displays good repeatability from 50 to 65 °C (optimal), and the coefficient of variation of Tt at the same concentration of nucleic acids is less than 5%. Our study optimizes the LAMP reaction using AuNRs, thereby reducing false positives and offering great potential for clinical diagnosis.
研究领域:
分子生物学
·
生物传感
·
临床诊断
·
病毒检测
·
纳米医学
·
转化医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Lancheng Wang,Mingjie Xu,Huimin Zhou,Kun Yan,Shiqi Duan,Dandan Xue,Youmei Wang,Bin Di,Chi Hu
The target of typical PCR analysis is restricted to nucleic acids. To this end, we report here a novel strategy to simultaneously detect genetic and metabolic markers using commercial PCR kits with cucurbit[8]urils (CB[8]) implemented to manipulate the activity of Taq DNA polymerase. CB[8] binds with the nonionic surfactants and displaces them from the polymerase surface, resulting in decreased enzyme activity. Meanwhile, the inhibited enzyme can be reversibly activated when spermine, the downstream metabolite of ornithine decarboxylase (ODC), is present in the sample, which competitively binds to CB[8] and recovers polymerase activity. CB[8] was implemented in conventional PCR kits not only to reduce false-positive results but also to extend the detection range of PCR technology. With this novel method to detect ODC in cell lysates containing both the nucleotides and intracellular metabolites, positive results were only observed in highly active HEK 293T cells, whereas silent cells treated with ODC inhibitor showed negative readouts, therefore providing a simple but elegant dual-modality PCR method for precision diagnosis.
研究领域:
分子生物学
·
生物技术
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NUCLEIC ACIDS RESEARCH
·
2025
·Vol. 53
·期 6
·
IF 13.1
Mao Shiqi,Wu Ruonan,Luo Weibang,Qin Jinshan,Chen Antony K
Clustered regularly interspaced short palindromic repeats (CRISPR)-based imaging tools that utilize fluorescently tagged single-guide RNAs (sgRNAs) have enabled versatile analysis of the dynamics of single genomic loci, but the accuracy may be hindered by nonspecific subnuclear probe accumulation, generating false-positive foci in cell nuclei. By examining the subcellular localizations of sgRNA expression plasmids, their RNA transcripts, and several RNA-binding proteins, we found that spuriously transcribed (cryptic) transcripts, produced by sgRNA expression plasmids, are the major contributors of false-positive signals, independent of sgRNA scaffold design or effector probe (i.e. RNA aptamer- or oligonucleotide-based probes) used. These transcripts interact with the paraspeckle core proteins, but not with the sgRNA expression plasmids or the paraspeckle RNA scaffold NEAT1_2, to form nuclear bodies that display liquid-like properties including sphericality, fusion competence, and sensitivity to 1,6-hexanediol. Transfecting sgRNA transcription units (i.e. sgRNA expression cassettes), lacking the plasmid backbones, reduces false-positive signals and enhances genomic imaging accuracy. Overall, this study unveils previously undescribed activities of cryptic plasmid transcripts and presents an easy-to-adapt strategy that can potentially improve the precision of CRISPR-based imaging systems that implement fluorescently tagged sgRNAs.
研究领域:
分子生物学
·
遗传学
·
生物物理学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Yanfeng Wang,Jing Zhang,Liangtao Pu,Miao Cao,Shangshang Dong,Chad D. Vecitis,Guandao Gao
Magnetic stir bars are routinely used by most of researchers in the fields of chemistry, biology and environment etc. An incredible phenomenon, in which the magnetic stirring increased reaction rate by tens of times under ultrasound irradiation, impelled us to explore roles of magnetic stirring. Unexpectedly, the thimbleful nano PTFE particles, from shell of magnetic stir bar, were exfoliated during magnetic stirring and account for ultrahigh tribocatalytic and piezocatalytic activities under ultrasonic irradiation. Reactive oxygen species (ROS), such as hydroxyl radical ( OH), superoxide radicals ( O 2 − ) and singlet oxygen ( 1 O 2 ) were generated in the present of PTFE under ultrasound irradiation, which is desired in the pollution control . The newly discovered PTFE activity, against the conventional wisdom that PTFE is inert, which also reminds the researchers that the trace amount of PTFE ground during magnetic stirring may inadvertently botch our experiments and introduce false positive results, especially involving routine magnetic stirring and ultrasound irradiation operation in laboratory. In addition, the safety and inertness of PTFE may require further review in PTFE-based commercial, industrial and biomedical settings.
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2019
·Vol. 7
·期 11
·1926-1932
·
IF 5.047
Fanyu Meng,Hua Chai,Xiaoyi Ma,Yuguo Tang,Peng Miao
Telomerase catalyzes the elongation of telomeres, which is closely associated with tumorigenesis. Therefore, development of reliable and convenient methods for telomerase activity analysis is critical for clinical diagnosis of cancers. However, most of the current probes for intracellular telomerase activity assay suffer from inevitable false-positive interferences. In this study, we have proposed a novel fluorescence resonance energy transfer (FRET)-based strategy for ultrasensitive monitoring intracellular telomerase activity with an amplification-free procedure. DNA nanoprobes constructed using a DNA tetrahedron and Flare DNA are designed to circumvent the problem of false-positive interference. Generally, telomerase catalyzes DNA extension and changes the configuration of the DNA nanoprobe, which finally leads to the increase of the distance between two labelled fluorophores. Based on the notably decreased FRET efficiency, a simple ratiometric sensor is established for the detection of telomerase activity at the single-cell level, which is much suitable for clinical applications. In addition, this method can be further applied in the detection of telomerase inhibitors, which is important for anti-cancer drug discovery.
研究领域:
分子生物学
·
生物技术
·
癌症研究
·
纳米技术
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYST
·
2023
·
IF 4.2
Wei Li,Huili Wang,Xinxin Ying,Zhen Liang,Jianna Li,Xiangjuan Chen,Lei Su,Xueji Zhang
Zr-metal–organic frameworks (Zr-MOFs) have received increasing interest for their use as the signal marker in the development of sandwich-structured aptasensors for the detection of exosomes. However, Zr4+ ions of the Zr-MOFs can interact with not only the exosomes, but also the aptamers, leading to possible false positives and a large background response. In the present study, we report for the first time aptasensors with Pd nanoparticle (NP)-decorated and hemin-embedded UiO-66 MOFs serving as the signal amplification marker to eliminate false positives and decrease the background response of aptasensors. To construct aptasensors for detection of exosomes, CD63-specific aptamers were tethered onto magnetic Fe3O4 particles coated with polydopamine (PDA) and UiO-66-NH2 using glutaraldehyde crosslinking for capturing the exosomes. To prepare highly catalytic Zr-MOF-based signal markers, UiO-66 MOFs were modified with hemin followed by Pd NPs. The as-prepared Pd-decorated hemin-embedded MOFs showed high catalytic activity towards the chromogenic oxidation reaction of TMB by H2O2. Moreover, the decoration with Pd NPs led to the change of the surface charge state of the catalytic hemin-embedded UiO-66 MOFs from positive to negative, weakening the interaction between the signal marker and the negatively charged aptamers. Therefore, the as-prepared aptasensors showed an improved sensing performance towards exosomes with a linear concentration range from 4.28 × 102 to 4.28 × 105 and a limit of detection (LOD) of 86.2 particles per μL. The as-prepared aptasensors also showed high sensitivity and selectivity to the exosomes from different origins including the HeLa cell line and MCF-7 cell line.
研究领域:
生物传感器
·
纳米技术
·
分析化学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2024
·Vol. 16
·期 11
·1538
·
IF 4.7
Boxuan Yao,Long Gu,Li Huang,Ruichun Li,Ze Fan,Zhongxiang Chen,Dongli Qin,Lei Gao
In this study, a highly efficient magnetic molecularly imprinted polymer nanocomposite material was prepared using multi-walled carbon nanotubes as carriers. The characterization of the obtained nanocomposite material was conducted using Fourier transform infrared spectroscopy, a vibrating sample magnetometer, a thermogravimetric analyzer, a scanning electron microscope, and a transmission electron microscope. The adsorption properties of the nanocomposite material were evaluated through adsorption experiments, including static adsorption, dynamic adsorption, and selective recognition studies. The prepared nanocomposite material, serving as a selective adsorbent, was applied in magnetic solid-phase extraction. Subsequently, the derivatized samples were analyzed for glucose in fish serum using liquid chromatography–tandem mass spectrometry. Under optimal conditions, the detection limit was 0.30 ng/mL, the quantitation limit was 0.99 ng/mL, satisfactory spiked recovery rates were obtained, and the relative standard deviation was less than 1.1%. Using 2-deoxy-D-ribose as the template molecule and a structural analog of glucose allowed us to eliminate the potential template leakage in qualitative and quantitative analyses, effectively avoiding the issues of false positives and potential quantitative errors, compared to traditional methods. A method for detecting glucose levels in fish serum based on molecularly imprinted polymer technology has been successfully developed to determine the stress and health levels of fish.
研究领域:
分析化学
·
材料科学
·
生物化学
·
环境科学
·
水产养殖
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）