最新刊期
卷 41 ， 期 4 ， 2022
- 摘要：Proteins involve in virtually all cell functions and participate in a variety of metabolic and physiological processes．Proteomics，which systematically analyzes the protein expression levels，modification states of proteins，and intracellular protein-protein interactions，provides a global perspective on how these molecules changes at different stages of disease occurrence and development．Recently，clinical proteomics has been proven to play a significant role in early diagnosis，prognosis，and monitoring of disease development．The concept of proteomics-driven precision medicine has been proposed thereby．In this review，the progress of proteomics-driven precision medicine（PDPM） and its application in the studies of major diseases are summarized.关键词：proteomics;mass spectrometry;biomarker;proteomics-driven precision medicine（PDPM）
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发布时间：2022-07-01 - 摘要：Molecular imaging has been widely applied to the research of fundamental biological processes，diagnosis，treatment design and therapeutic outcome assessment on many diseases．Hemicyanine（HCy） dye is a suitable bioimaging agent due to its good photophysical properties，biocompatibility and low toxicity to living systems．A huge amount of research work involving probes based on the HCy dye for molecular imaging has emerged in recent years．This review focuses on the development of probes based on HCy dye for fluorescence and multimodal imaging in a systematic manner．Design strategies of the activatable HCy probes and their successful applications as bioimaging agents are described in detail. In addition，the future development of HCy probes for molecular imaging is discussed．关键词：hemicyanine;molecular imaging;fluorescence imaging;multimodal imaging
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发布时间：2022-07-01 - 摘要：Alkaline phosphatase（ALP） is a hydrolase that can catalyze the removal of the phosphate group from proteins，nucleic acids and carbohydrates．ALP widely exists in both prokaryotes and eukaryotes and plays an important role in regulating various biological processes such as cell division，proliferation，apoptosis and signal transduction．The dysregulation of ALP activity is closely associated with a variety of human diseases including cardiovascular diseases，diabetes and cancers，making it a promising biomarker for disease diagnosis．Thus，sensitive detection of ALP activity is essential to clinical diagnosis and biomedical research．In this review，the emerging strategies for in vitro detection and in vivo imaging of ALP in recent years are summarized．The in vitro detection methods include colorimetry，electrochemistry，surface enhanced Raman scattering and fluorescence measurements，while the in vivo imaging methods mainly rely on fluorescence imaging．Moreover，new insights into the challenges and future directions of ALP assay are given．关键词：alkaline phosphatase;colorimetry;electrochemistry;surface enhanced Raman scattering;fluorescence analysis;bioimaging
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发布时间：2022-07-01 - 摘要：Metal-organic frameworks（MOFs） have played important roles in a wide range of fields，such as gas storage and separation，fuel cells，energy conversion，and chemical/biological sensors．When one of the dimensions is scaled down to nanometer，MOFs can be named as nanoscale MOFs（nMOFs）．Compared with the traditional MOFs，nMOFs retain the advantages of highly ordered porosity，structural tunability，more effective surface modification sites and improved biological distributions．nMOFs are biocompatible molecular nanomaterials with great potentials in various biomedical applications，especially for detection of tumors and tumor markers．In this review，recent progress in nMOFs for biological imaging of tumors and tumor markers is summarized．Different bioimaging techniques including fluorescence imaging，magnetic resonance imaging（MRI），photoacoustic imaging（PAI），computed tomography imaging（CTI），positron emission tomography imaging（PETI） are introduced．After that，multimodal imaging superimposed by two or more imaging modalities is highlighted. Finally，a brief conclusion about this special field is provided．Priorities of research in nMOF-mediated therapies and the prospects of clinical applications of nMOFs as delivery carriers and cancer therapeutics are also outlined．This review is expected to advance our understanding of this special field，and promote the applications of nMOFs in early diagnosis of disease and tumor therapy．关键词：nanoscale metal-organic frameworks（nMOFs）;biological imaging;tumor markers;biomedicine
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发布时间：2022-07-01 - 摘要：I-motif，as a novel pH-sensitive element，has attracted extensive attention and research upsurge in the field of biomedicine due to its ability of fast conformation alteration at different pH conditions，as well as the advantages of automatic synthesis，excellent biocompatibility and flexible functional integration．In this review，the basic performances of i-motif are firstly described．Then，the applications of i-motif-based nanosystems in biomedical field are reviewed from three aspects of cellular pH imaging，pH-controlled drugs release and pH-responsive tumor theranostics applications．Finally，some of the current challenges of the i-motif-based nanosystems for the biomedical applications are pointed out，and an insight into the future prospects of i-motif-based nanosystems for precision medicine is provided．关键词：i-motif;pH imaging;pH-controlled drugs release;pH-responsive tumor theranostics
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发布时间：2022-07-01 -
A Low-cost，Automated Nucleic Acid Extraction System Converted from the Open-Source RepRap 3D Printer
摘要：Automatic nucleic acid extraction is essential for nucleic acid detection such as DNA amplification and high-throughput sequencing. Currently，most commercial nucleic acid extractors are mainly based on magnetic separation technology，adopting a highly integrated structural design or a closed solution，which is too costly and not conducive to use in resource-limited areas. In addition，it is difficult to update the functionality of the instruments once the functional module is determined. To address these challenges，a desktop automated nucleic acid extraction system was built in this work，which was converted from a low-cost 3D printer based on the Self-Replicating Rapid Prototyping （RepRap） open-source project. With the RepRap open-source design，the module function of the system could be flexibly designed and programmable，thus allowing updates as needed，which significantly shortened the manufacturing and testing cycle of the system. In the developed system，the modular function of the heating，mechanical motion and multi-channel magnetic separation could be fully integrated with the open-source 3D printing hardware. an 8-channel magnetic separation based nucleic acid extraction module was designed，which could be assembled onto the original 3-axis motion platform by replacing the 3D printer extruder. The motion path planning required for automatic extraction was realized by G-code programming. The experimental protocols and control software were developed for the automated nucleic acid extraction in this work. The 3-axis motion platform and nucleic acid extraction module could be effectively controlled by the host computer and the module drive circuit，respectively. The heating module consisted of 4 custom-made aluminum heating bases and the heating plate on the 3D printer. The heating bases were adapted to a 96 deep-well plate，so that the deep-well plate is well attached to the heating block for high heating efficiency. By using the λDNA as the standard nucleic acid samples，the extraction performance of the system had been verified by evaluating extraction purity，and efficiency including consistency and stability. From the results，the system showed a better extraction purity and efficiency for the samples with high concentration than that with low concentration. Additionally，the 8-channel extraction experiment for the plasmid DNA from the cultured E. coli cells had been successfully carried out on the automated system in this study. This validation further demonstrated that the automated system can be utilized for extracting nucleic acids from real cell samples. Overall，the nucleic acid extraction system developed in this study is expected to provide a cost-effective means for rapid point-of-care molecular testing in resource-limited environments outside the laboratory.关键词：molecular diagnosis;magnetic separation;nucleic acid detection;open-source hardware- 3
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发布时间：2022-07-01 - 摘要：Adenosine-to-inosine（Ade-to-Ino）RNA editing is one of the most widespread post-transcriptional modifications in RNA．The conversion of adenosine to inosine is through the hydrolytic deamination of the amino group at the C6 position of adenosine，which is catalyzed by the adenosine deaminases acting on RNA（ADARs）．Accumulated lines of evidence show that Ade-to-Ino RNA editing is involved in the regulation of gene expression and protein functions．Aberrant Ade-to-Ino RNA editing is demonstrated to be correlated with many human diseases．In-depth investigation of the biological functions of Ade-to-Ino RNA editing depends on the sensitive detection，accurate quantification，and precise mapping analysis．This review provides an overview of the recent advances in analytical methods and techniques for the detection，quantification and location analysis of Ade-to-Ino RNA editing in a wide range of RNA molecules．The principles，advantages，limitations and applications of these established methods are discussed．It is hoped that this review could stimulate the development of analytical methods to decipher Ade-to-Ino RNA editing and expedite the elucidation of the functions of Ade-to-Ino RNA editing in various RNA species．关键词：adenosine-to-inosine RNA editing;RNA modification;detection method;mapping analysis
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发布时间：2022-07-01 - 摘要：Clustered regularly interspaced short palindromic repeats（CRISPR） and CRISPR－associated proteins（Cas） have become highly promising candidates in the construction of biosensing systems and diagnostic devices，in addition to their roles as revolutionary genome engineering tools．For in vitro diagnostics，the class Ⅱ CRISPR/Cas systems possess unique advantages，such as high detection sensitivity and specificity，and the feasibility for developing point－of－care diagnostic technology．This minireview briefly introduces the working mechanism of CRISPR/Cas systems and mainly focus on the various diagnostic methods based on the CRISPR/Cas for detecting different forms of the genetic molecules in recent three years according to different readout methods．关键词：CRISPR/Cas;molecular diagnosis;point－of－care testing;biosensing
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发布时间：2022-07-01 - 摘要：In the field of regenerative medicine，the regulation effect of materials on cell growth and tissue repair has always been a critical issue．With the development of surface patterning technique，it has become possible to prepare regular，controllable，and diverse patterned areas on the surface of materials．Therefore，patterning technque is widely used in related disciplines such as regenerative medicine，tissue engineering and cell diagnosis．Micro/nano surface patterning methods are used to change the chemical properties and topological structures of materials，so as to achieve the regulatory effect on cell adhesion，migration，proliferation，apoptosis，gene expression and cell differentiation，which have attracted more and more attention．This type of research is currently quite rich and diverse，involving a variety of micro/nano structures，substrate materials，modified materials，cell types and cell behavior. The micro/nano surface patterning methods mainly used in the current experiments are introduced in this article．Meanwhile，the research work in the field of material micro/nano structure regulation of cell behavior is also summarized from the aspects of anisotropic topological structure，isotropic topological structure and composite structure．Finally，the specific relationship between cell behavior and growth environment is summarized，so as to provide references for the design of scaffolds and implants used in regenerative medicine．关键词：micro/nano structure;patterned surface;cell orientation;regenerative medicine
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发布时间：2022-07-01 - 摘要：The illicit drug issues have always been a social disease plaguing the world．Simple，rapid and sensitive drug detection methods play an important role in drug identification，drug use identification and drug rehabilitation monitoring. In recent years，the researches on rapid detection methods for drugs are mainly based on immunoassay，mass spectrometry and spectroscopy．Immunoassay technique with low cost and simple operation is suitable for screening in field tests and large sample group tests．Mass spectrometry analysis is time-saving，suitable for rapid screening and high throughput analysis，while portable mass spectrometry could be used for rapid detection of drugs in the field．Spectroscopy has attracted a widespread attention due to its advantages in drug detection，such as rapid nondestructive，fingerprint identification，high sensitivity and high accuracy．The research progresses on rapid detection methods for drugs in recent years are summarized in this paper．Meanwhile，the shortcomings，challenges and prospective of various techniques are also discussed．The purpose of this study is to provide a reference for researchers to develop rapid drug detection methods，so as to promote the continual development of rapid drug detection techniques.关键词：illicit drug;rapid detection;immunoassay;mass spectrometry;spectroscopy
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发布时间：2022-07-01 - 摘要：Specific targeting of cancer cells is the key to accurate diagnosis and efficient treatment．Among current delivery strategies，small molecule-based precursor probes（or drugs） are limited by their rapid body metabolism and toxicity on healthy organs，while the efficacies of nanoprobes（or nano drug carrier） are hampered by their unclear molecular weight，low biological penetration and easy capture by the reticuloendothelial system. The strategy of "in situ self-assembly" combines the advantages of both small molecules and nano-systems．The use of small molecule as precursor could improve the biological penetration of drugs in tumor tissues，while the nanostructures formed by self-assembly after reaching the target site may provide better bioavailability，higher metabolic stability and longer residence time．On this basis，a cascade self-assembly/disassembly strategy for accurate localization in tumor and high selectivity towards tumor cells was further developed by applying multiple tumor－specific biomolecules to sequentially activate molecular precursors．In the diagnosis and treatment of cancer，this strategy could effectively improve the sensitivity of diagnostic signals，track a series of dynamic biological processes in cancer cells，and achieve effective drug accumulation in tumor cells while reduce side effects on normal cells．In this paper，the current progress of enhanced cascade self-assembly and disassembly of small molecules are summarized，which provides new insights for cancer diagnosis and treatment.关键词：in situ self-assembly;cascade self-assembly/disassembly;accurate delivery;cancer diagnosis and treatment
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发布时间：2022-07-01 - 摘要：Alzheimer's disease is one of the most serious neurodegenerative diseases in the world．The brain of Alzheimer's patient after death showed two main neuropathological changes，i.e. senile plaques and neurofibrillary tangles，while the typical clinical symptoms of Alzheimer's disease include memory loss，mood swings，cognitive decline，and difficulty in speaking，writing and walking．Early diagnosis is essential for the prevention or treatment of Alzheimer's disease by introducing proper intervention．Biomarkers associated with Alzheimer's disease such as proteins，genes，miRNAs，complement system，kinin system and metal ions are reviewed in this paper，and the current clinical diagnostic methods and kits for Alzheimer's disease are also summarized．There is an urgent need to develop simple，rapid，and less invasive diagnostic techniques due to the invasion and high cost of the current methods．Meanwhile，the novel emerging detection methods based on immunoassay，fluorescence，bio-imaging，electrochemistry，nanotechnology and miRNAs are also presented，which have pushed forward the way of early diagnostics of Alzheimer's disease.关键词：Alzheimer's disease;amyloid β-protein;tau protein;novel biomarkers;molecular diagnostics
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发布时间：2022-07-01 - 摘要：Vibrio vulnificus（V.vulnificus） is an important marine foodborne pathogen，which could infect a variety of aquaculture animals and humans via a wound or intestinal infection．Moreover，this bacteria have the highest mortality among various foodborne pathogens，occurring rapidly．Therefore，the detection of V.vulnificus is very significant for food safety and the diagnosis of patients．However，traditional detection methods still have some limitations，such as cumbersome steps and long time-consuming．Meanwhile，they also limit the accuracy of medical inspection and food safety detection．In recent years，based on the rapid development of molecular biology and immunology，as well as the rise of nano science and technology，domestic and foreign scholars have studied and established varieties of rapid detection techniques for V.vulnificus，with the characteristics of simple operation，accuracy，high efficiency and high sensitivity，providing a new idea for the further development of rapid detection methods of V.vulnificus．Thus，this paper reviews and summarizes the traditional and emerging detection methods of V.vulnificus，such as microbial traditional pathogenic detection technique，immunological detection technique，molecular biology detection technique，biochip and biosensor technique，in order to provide a scientific basis for the effective prevention and control of V. vulnificus，as well as the diagnosis and treatment of patients.关键词：Vibrio vulnificus;foodborne pathogens;detection technology
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发布时间：2022-07-01 - 摘要：DNA self-assemblies play an increasingly significant role in biosensing，drug delivery and therapy due to their minimal toxicity，high biocompatibility and built-in features．Compared to most natural polymers or synthetic fibers，these DNA molecules could be relatively strong while also modifiable through sequence variation．By simply attaching to a polymer as a side chain，the secondary structure formed could endow the DNA structure with designable responsiveness to something like metal ions，proteins，pH，DNA，RNA，and some other small signal molecules（such as ATP） response to achieve some functional self-assemblies．In this review，the most recent progress of DNA self-assembly is introduced．The focus is on the initiator to distinguish the trigger mechanism and their fluorescence imaging applications.关键词：in-situ DNA self-assembly;fluorescence imaging;living cell;trigger mechanism
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发布时间：2022-07-01 - 摘要：Diabetes mellitus（DM） is the third major non-communicable disease which threatens human health after tumor and cerebro-cardiovascular diseases in the world．Blood glucose detection（BGD） is the scientific basis for doctors to diagnose DM，making and adjusting treatment plan for DM patients．Non-invasive BGD techniques，which will inevitably replace the traditional invasive and minimally invasive BGD techniques in future，have an important application value and broad market prospects．In the last two decades，researchers have proposed a variety of BGD methods based on different physical principles．The basic principles，advantages and disadvantages of various non-invasive BGD methods are respectively described in this paper according to the optical and non-optical categories，and the development trend of non-invasive BGD technques in the future is discussed.关键词：diabetes mellitus（DM）;blood glucose;non-invasive blood glucose detection;optical method;non-optical method
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发布时间：2022-07-01 - 摘要：The microenvironment of tumor has a series of abnormal features，including low pH values，hypoxia，excess glutathione，increased oxidative stress and overexpressed enzymes．These endogenous factors play an important role in tumor proliferation，invasion，migration and neoangiogenesis，but they also provide opportunities for tumor precision diagnosis and treatment．The development of endogenous stimuli responsive platforms has become a research hotspot．Therefore，the design principles and the recent progress of various kinds of endogenous stimuli responsive diagnosis and treatment agents developed in recent years are summarized in this paper．The challenges and perspectives of the stimuli responsive platforms are discussed with a view to providing a theoretical basis for the construction of intelligent theranostics system．关键词：endogenous;stimulus response;precision theranostics;tumor;research progress
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发布时间：2022-07-01
Reviews
- 摘要：Early accurate detection of malignancy tumor plays a key role in reducing cancer mortality．Current detection strategies mainly rely on the imaging technologies．However，single-modality biomedical image cannot provide enough information due to its inherent defects．Therefore，the dual-modal biomedical imaging strategies which can provide more available information for precise cancer diagnosing，have become a hotspot for research．Among the biomedical imaging methods applied in clinical，magnetic resonance imaging（MRI） is considered to be an effective method for clinicopathological diagnosis due to its high three-dimensional（3D） spatial resolution and high soft tissue resolution，but it has also been plagued by the long inspection time and expensive inspection fee．Whereas，thermal imaging is an efficient and minimally invasive method for biomedical imaging，which could offset the above deficiencies of MRI．Most importantly，it is convenient and economical．Furthermore，the development of multifunctional nanoparticles brings more possibilities for the establishment of novel tumor diagnostic platforms，which is expected to have a greater impact in the field of biomedical imaging．Thus，a kind of highly biocompatible multifunctional nanoparticles（CuSSe NPs） were prepared by a facile one-pot hydrothermal method for tumor MRI/thermal imaging in this study．The diameter of CuSSe NPs is about 100 nm，and it exhibited an excellent dispersity in aqueous solution．However，the CuSSe NPs did not exhibited the best MRI capability due to the existence of diamagnetic Cu（Ⅰ），but in vivo experiments demonstrated that the CuSSe NPs could specifically respond to the excess hydrogen peroxide（H2O2） at the tumor site so as to realize the conversion of diamagnetic Cu（Ⅰ） to paramagnetic Cu（Ⅱ），acting as in situ autogenous MRI agents for visualizing and diagnosing the location of cancer．Moreover，attributing to the intensive absorption in the second near-infrared（NIR－Ⅱ） region，CuSSe NPs exhibited as a concentration- and laser－power-dependent photothermal imaging agent with considerable photothermal conversion effects in the NIR－Ⅱ region．The photothermal conversion efficiency of CuSSe NPs was calculated to be－48% under the illumination of NIR－Ⅱ laser（1 064 nm）．Both in vivo and in vivo experiments demonstrated that CuSSe NPs have good thermal imaging capabilities for real-time cancer monitoring．Furthermore，the blood analysis on the mice injected with or without CuSSe NPs were evaluated after 3 and 25 days．The results showed that CuSSe NPs were highly biocompatible without acute and long-term toxicity．Consequently，the constructed copper-based multifunctional NPs have been demonstrated to be a potential nanoprobe for dual-modal imaging with high tumor contrast in clinical cancer theranostics．关键词：H2O2-activatable;in situ autogenous MRI;thermal imaging;NIR－Ⅱregion;cancer diagnosis
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发布时间：2022-07-01 - 摘要：DNA nanotechnology has attracted a broad research interest in biosening field，in which various functional two- or three-dimensional DNA nanostructures have been constructed．Rolling circle amplification（RCA） as an isothermal amplification technique has provided a new way for the design and self-assembly of DNA nanomaterials．Herein，the horseradish peroxidase（HRP）-embedded DNA nanoflowers（HRP@DNFs） are one-pot synthesized by RCA，which are further applied to the fabrication of photothermal biosensor for highly sensitive and selective detection of circulating tumor cells（CTCs） in hepatocellular carcinomas（HCCs） based on dual-aptamer recognition. After encapsulation of HRP into DNFs，the catalytic activity of HRP is significantly enhanced due to the formation of highly ordered and hydrogen-bonded water environment．For HCCs detection，the aptamer TLS11a that can specifically recognize the HepG2 HCCs is designed in DNFs as the signal amplification labels，while the EpCAM aptamer-modified magnetic beads（EpCAM-MBs） are prepared as the carrieres to capture HepG2 cells．In the presence of HepG2，the sandwich structure of MBs/HepG2/HRP@DNFs is formed via specific dual-aptamer recognition. After magnetic separation and addition of 3，3'，5，5'-tetramethylbenzidine（TMB） and H2O2 into the system，the HRP@DNFs can catalyze the oxidation of TMB．Upon irradiated by 808 nm infrared laser，a strong photothermal conversion effect is produced by oxidized TMB，resulting in the photothermal detection of HepG2 cells with high sensitivity and specificity．Overall，the proposed strategy for one-pot self-assembly of enzyme-embedded DNA nanoflowers possesses a great potential in early diagnosis of diseases，especially cancers．关键词：rolling circle amplification;DNA nanoflowers;photothermal biosensor;circulating tumor cells;aptamer
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发布时间：2022-07-01 - 摘要：The trans-cleavage activity of CRISPR－Cas12a system could be activated after it recognizes the specific DNA activator sequences，which paves the foundation not only for direct target DNA detection but also for expanding indirect biosensing of various biomolecules．However，both double-strand DNA（dsDNA） and single-strand DNA（ssDNA） activators with varying structures are employed in the existing literatures，and there still lacks systematic guiding principles for Cas12a activator design．Herein，the impact of DNA activator structures on the trans-cleavage activity of LbaCas12a is systematically studied by monitoring the fluorescence signal generated under the guidance of the same crRNA．According to a series of comparison，the following conclusions have been drawn for the sequence design of DNA activators．（1） protospacer-adjacent motif（PAM） site helps LbaCas12a to target the dsDNA activators and the ssDNA activators with higher efficiency．（2） lacking the sequence fragment in the proximal region of PAM will reduce the efficiency of Cas12a-crRNA in positioning the activator．（3） pre-deletion of the fragment adjacent to the crRNA-pairing sequence in the PAM－distal end is conducive to the LbaCas12a trans-cleavage activity．（4） ssDNA activators generally have better performance in activating the trans-cleavage activity of LbaCas12a than dsDNA activators due to the omission of dsDNA unzipping．According to these findings，an efficient LbaCas12a-preferred activator structure is recommended，which could yield 3.7 times higher fluorescence intensity than the widely applied PAM-containing dsDNA activator．The results presented in this study may help the fabrication of high-efficient CRISPR－Cas12a-based in vitro biosensing systems．关键词：Cas12a;protospacer adjacent motif（PAM）;dsDNA activator;ssDNA activator;in vitro biosensing
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发布时间：2022-07-01 - 摘要：A facile assembly－fission method combined with dialysis post-treatment strategy was adopted to prepare a kind of ultra-small size focused fluorescent sulfur quantum dots（SQDs）．The as-prepared SQDs were characterized by transmission electron microscopy（TEM），energy-dispersive X-ray spectroscopy（EDX），UV－Vis absorption spectrometry（UV－Vis） and fluorescence spectrometry．The photoluminescence properties of the SQDs were investigated in detail，which indicated that the SQDs with the average diameter of 2.2 nm exhibited an excitation-independent emission and an optical stability in aqueous solution．Meanwhile，the fluorescence of the SQDs could be quenched by Fe3+ significantly，and the mechanism for the fluorescence quenching was via inner filter effect（IFE）．Based on the fluorescence quenching effect of the Fe3+/SQDs system，a facile fluorescence sensing platform was successfully constructed for the highly selective and sensitive detection of Fe3+．The proposed SQD-based sensor showed a wide response to Fe3+ in the range of 5－600 μmol/L，with a detection limit（LOD） of 1.19 μmol/L．In addition，this method，with significant advantages of high sensitivity，high selectivity，simplicity and economy，was successfully applied to the detection of Fe3+ in human serum，avoiding the deficiencies of complex sample preparation and expensive detection conditions．Thus，this method has a potential application prospect in clinical diagnosis，and opens up a new way for the design of effective fluorescent probes for other biologically related targets．关键词：sulfur quantum dots;assembly－fission;dialysis post-treatment;ferric iron
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发布时间：2022-07-01 - 摘要：Cancer ranks as the leading threat to life expectancy all over the world，based on the latest estimations. Timely diagnosis and treatment of malignancies are still essential procedures to control the growing burden of cancer incidence and mortality．Single particle inductively coupled plasma mass spectrometry（spICP－MS） is a detection method for single particles in time-resolved mode．Inheriting the advantages of ICP－MS，spICP－MS ensures the single-particle counting with high sensitivity and high element resolutions．For immunoassays by this mode，there are breakthroughs not only in improving the detection limits of heterogeneous immunoassay but also in achieving multiplex homogeneous immunoassays with a simpler procedure．In this work，a single particle counting strategy was achieved by spICP－MS for sensitive carcinoembryonic antigen（CEA） evaluation．Gold nanoparticles（AuNPs） with a diameter of 50 nm were synthesized by one-step sodium citrate reduction，which were further applied to CEA-specific capturing. Anti-CEA antibody labeled AuNPs were synthesized by electrostatic adsorption between disulfide bonds exposed on the anti-CEA antibodies and the surface of AuNPs．The strategy was based on sandwich immunoassay where anti-CEA antibody labeled magnetic beads（MBs） were applied to capture CEA and antibody labeled AuNPs．After separation by a magnet，MBs were enriched at the bottom of the centrifugal tube，while the remaining AuNPs in the supernatant were counted by spICP－MS．The more CEA occurred in the sample，the more AuNPs probes were captured on the surface of MBs，and the fewer numbers of detectable remaining AuNPs were found in the supernatant．The proposed method was more direct and facile without washing steps，compared with the traditional MBs strategy．The experimental conditions were optimized，including magnetic beads volume applied in immunoassay and dilution ratio of the sample in spICP－MS．Under the optimal conditions，spICP－MS could accurately determine the change of AuNPs numbers in the process of CEA immunoassay，with an efficiency of 2.1%．The proposed method provided a three-orders-of-magnitude linear range（0.05－20 ng/mL，r2 = 0.997） with a limit of detection（LOD） as low as 0.017 ng/mL for CEA quantification．The method was also successfully utilized in serum sample analysis with good selectivity，exhibiting a great potential in cancer diagnosis．关键词：single particle ICP－MS;AuNPs;magnetic beads;CEA evaluation
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发布时间：2022-07-01 - 摘要：The condition of patients with esophageal squamous cell carcinoma（ESCC） is difficult to be found and effectively treated in the early stage of the disease due to the few types and low levels of tumor markers in the body. Therefore，it is the most urgent problem for researchers to find a suitable marker for rapid and efficient detection. Platelet derived growth factor－BB（PDGF－BB） is extremely important for the early diagnosis of malignancy. A DNA biosensor based on enzyme cycle amplification fluorescence spectroscopy was designed for PDGF－BB detection in this work，using a shearing enzyme that can cut the specified site to achieve the signal amplification，reducing the limit of detection from 1 fmol/L to 1 amol/L，greatly improving the sensitivity of detection. This method is of great value in biochemical and medical applications for its simple，rapid and efficient diagnosis and detection on esophageal squamous cell carcinoma.关键词：tumor markers;DNA biosensors;enzyme cycle amplification;fluorescence detection
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发布时间：2022-07-01 - 摘要：This manuscript demonstrated a universal platform for bacteria assay by using a fluorescein isothiocyanate-labeled lysozyme（FITC－Lys） and polyethylenimine-modified positively charged gold nanoparticles（PEI－AuNPs） constructed fluorescence resonance energy transfer（FRET） sensor based on its electrostatic binding with bacteria. In the presence of the bacteria，the energy donor of positively charged FITC－Lys bond with the bacteria through both the recognition to peptidoglycan of cell wall and electrostatic interaction while the energy acceptor of positively charged PEI－AuNPs bond with the bacteria based on the electrostatic interaction，which decreases the distance between energy donor and acceptor and then causes fluorescence quenching，showing FRET“on”signal readout mode with the low fluorescence intensity. PEI－AuNPs were synthesized by hydrothermal method and characterized by ultraviolet spectrum，transmission electron microscope，and laser particle size analyzer. The results shown that PEI－AuNPs with diameter about 9.6 nm had maximum ultraviolet absorption at 526.5 nm，and they were positively charged. The method developed in this study could detect 10 different kinds of bacteria such as Staphylococcus aureus，Streptococcus pneumoniae，Enterococcus faecalis，Staphylococcus epidermidis，Listeria monocytogenes，Escherichia coli，Salmonella typhimurium，Salmonella paratyphoid A，Vibrio parahaemolyticus，and Pseudomonas aeruginosa. Then，the interference of possible interfering components in actual samples（taking milk and juice as examples） on the detection was further discussed. The results showed that under our experimental conditions，the interfering components such as proteins，ions，and others in the samples would not interfere with the analysis results after ten times dilution. This strategy showed feasibility as a universal assay platform for broad spectrum bacteria，which is interesting for the control of pathogenic bacteria.关键词：bacteria;lysozyme;gold nanoparticle;FRET
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发布时间：2022-07-01 - 摘要：Compared with polymerase chain reaction（PCR） nucleic acid amplification，loop-mediated isothermal amplification（LAMP） does not require thermal cycling instruments，which is more suitable for rapid on-site detection．However，the small Stoke′s shift of currently used organic fluorescent dye for visualized LAMP leads to insufficient color differentiation．In this study，the nucleic acid molecule“light switch”［Ru（bpy）2（dppz）］2+ was exploited as a LAMP fluorescent dye to establish a rapid visualized closed-tube method for LAMP detection．Visualization detection requires a high concentration of dye，but its adding before amplification reaction will strongly inhibit LAMP reaction，while its adding after reaction by opening the lid will lead to a serious aerosol cross contamination．Therefore，wax was chosen to seal the［Ru（bpy）2（dppz）］2+ at the bottom of the tube，and the LAMP amplification products were visually detected by using the strong red fluorescence emission of ［Ru（bpy）2（dppz）］2+ in the presence of double-strand DNA．The S.aureus DNA could be detected as low as 20 copies/reaction with strong specificity，and the whole visual detection process could be completed within 1 h．It could be widely used for the rapid on-site nucleic acid detection in the fields of environmental detection，food safety and clinical diagnosis．关键词：LAMP isothermal amplification;［Ru（bpy）2（dppz）］2+;visual detection;S. aureus
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发布时间：2022-07-01 - 摘要：A fast screening method was developed for the analysis of five extremely polar poisons in whole blood sample using paper capillary spray（PCS） tandem mass spectrometry．The five extremely polar poisons are diquat，paraquat，glyphosate，glufosinate-ammonium and succinylcholine chloride．The whole blood sample was extracted with methanol，at a ratio of 1 to 9（by volume） for sample and methanol．After mixing the sample and keeping it static，100 μL supernatant was loaded onto the paper capillary spray cartridge．The cartridge was then inserted into the inlet of PURSPEC MS Mate interface，which was coupled to a Shimadzu 8040 tandem mass spectrometry system．Afterwards，the analytes were directly analyzed qualitatively and quantitatively using the two precursor ion-product ion pairs with multiple reaction monitoring（MRM） mode．With the help of no complicated sample preparation provided by PCS cartridge as an ambient ionization technique，together with the direct coupling of PCS to commercial instrument by MS Mate，the five polar targets could be detected within 1 minute，which is much faster than current methods．During the research process，the mass spectrometry parameters were optimized first，and the ion pairs for each analyte were found with their corresponding standard solutions．The qualitative and quantitative ion pairs are listed as follows：diquat（positive mode，183.1 > 157.0*，183.1 > 130.0），paraquat （positive mode，185.1 > 170.1，186.1 > 171.1*），glyphosate（negative mode，168.0 > 63.0，168.0 > 150.0*），glufosinate-ammonium（negative mode，180.1 > 85.0*，180.1 > 136.0），and succinylcholine chloride （positive mode，145.1 > 93.6，145.1 > 115.5*），where the ion pairs with the asterisk refer to quantitative ion pairs. The limits of detection（LODs） for the five polar compounds in blood sample were 0.05 mg/L for diquat，0.5 mg/L for paraquat，25 mg/L for glyphosate，25 mg/L for glufosinate-ammonium，and 0.05 mg/L for succinylcholine chloride．Here the definition of signal-to-noise（S/N） ratio no less than 3 was used for LOD measurement．Linearity was measured by spiking analyte standards to the methanol extracted supernatant from blank blood sample．Good linearity was achieved in the range of 0.005－0.5 mg/L for diquat and succinylcholine chloride，in the range of 0.05－5 mg/L for paraguat，and in the range of 2.5－100 mg/L for glyphosate and glufosinate-ammonium．The spiked recovery ranged from 62% to 117% with relative standard deviation less than 40% under 1，2，10 times detection limit．Using the method developed in this article，whole blood samples from poisoned patients were analyzed and the corresponding poisons were correctly identified and quantified，which shows that the performance of the PCS－MS Mate－MS/MS method meets the need in real life for fast screening analysis．The method is convenient and suitable for the fast screening of polar poisons in blood samples.关键词：paper capillary spray;ambient ionization;polar compounds;blood sample
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发布时间：2022-07-01
Scientific Papers
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