A novel CRISPR/Cas14a system integrated with 2D porphyrin metal-organic framework for microcystin-LR determination through a homogeneous competitive reaction.
TL;DR: In this article, a 2D porphyrin metal-organic framework nanosheets (2D-pMOFs) was used to detect microcystin-LR.
About: This article is published in Journal of Hazardous Materials.The article was published on 2021-11-05 and is currently open access. It has received 18 citations till now. The article focuses on the topics: Porphyrin & Detection limit.
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TL;DR: In this article , the Capture-SELEX (systematic evolution of ligands by exponential enrichment) screening strategy of LEV aptamers, using streptavidin modified agarose beads as a solid phase medium to separate target-bound and unbound ssDNA, was described.
8 citations
TL;DR: In this paper , a fluorometric biosensor named HARRY (highly sensitive aptamer-regulated Cas14 R-loop for bioanalysis) was developed, which can detect ATP, Cd2+, histamine, aflatoxin B1, and thrombin with detection limits at the low-nanomolar level, which shows improvement compared with Cas12a-based aptasensors in sensitivity and versatility.
7 citations
TL;DR: Wang et al. as mentioned in this paper used the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 and recombinase polymerase amplification (RPA) integrated lateral flow biosensor (LFB), namely CCR-LFB, to detect Staphylococcus aureus.
Abstract: Bloodstream infections have become a major global public health problem with high mortality. Rapid and robust pathogen diagnostics are necessary for improving patient care. Herein, we report an assay for the detection of Staphylococcus aureus (S. aureus) based on the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 and recombinase polymerase amplification (RPA) integrated lateral flow biosensor (LFB), namely CCR-LFB. Unlike existing LFBs based on dual-labeled amplicon bridging, CCR-LFB uses CRISPR/Cas9-mediated specific recognition of the amplicons induced by S. aureus DNA to form complexes that bind gold nanoparticles (GNPs) to the test (T) line. This rational design can completely overcome primer-dimer interference without reducing amplification efficiency, thereby improving sensitivity and robustness. Under optimal experimental conditions, S. aureus as low as 102 CFU/mL can be visually judged and a detection limit of 63 CFU/mL was achieved by ImageJ analysis. Additionally, this method has been successfully used to detect S. aureus in real blood samples without any cross-reaction. We hope that this method can serve as a model tool to meet the growing need for point-of-care diagnosis of bloodstream infections.
6 citations
TL;DR: In this paper , a detailed overview of different proteins, recognition elements and signal amplification methods used in the field of molecular diagnostics based on the CRISPR/Cas system is presented.
Abstract: Food safety is a major global public health issue. The majority of traditional culture-based methods have lengthy detection times, require sophisticated sample pretreatment, preparation of high-quality primers, and trained personnel. As these are not always available, there is an urgent need for rapid, sensitive, portable, and specific detection technology. This review introduces new tools in the field of molecular diagnostics based on the CRISPR/Cas system. It gives a detailed overview of different proteins, recognition elements and signal amplification methods. CRISPR systems have been fused with different technologies to create detection platforms that can detect and amplify very weak signals, increase the detection efficiency, and create new channels for effective rapid food analysis. It can detect a wide range of targets, including bacteria, fungi, pesticides, metal ions, genetically engineered crops, adulterated food, etc. Finally, we discuss the benefits and future challenges of these new detection tools, as well as the prospects of combining them with other techniques. Food safety is a global concern. In recent years, the newly developed CRISPR/Cas toolbox has shown good prospects in the field of molecular detection. The system is first coupled with various components for signal conversion, and then combined with nucleic acid amplification, allowing the development of a new generation of detection and sensing platforms. Nevertheless, CRISPR/Cas technology still faces various challenges on the way to fully mature development despite its outstanding advantages in detection. Today, the development of CRISPR/Cas-based detection tools aims at reducing the number of steps, using multiple pathways, increasing speed and efficiency, as well as integrating intelligent genetic circuits, which have great potential for advancing the diagnosis and prevention of foodborne diseases and food safety.
6 citations
TL;DR: In this paper , a facile dimensionality reduction strategy was proposed to improve the catalytic activity of metal-organic framework (MOF)-based nanozymes, and the peroxidase-like activity of the prepared bimetallic Co-Fe NDs was almost tripled.
Abstract: The antibacterial strategy using cutting-edge metal-organic framework (MOF)-based nanozymes can effectively solve the problem caused by antibiotic resistance to protect human health and the environment; however it has been significantly limited by the complicated modification method and non-ideal catalytic activity. Herein, we report a facile dimensionality-reduction strategy to improve the catalytic activity of MOF-based nanozymes. By reducing the dimensionality of two-dimensional Co-TCPP(Fe) (Co-Fe NSs) to zero-dimensional Co-TCPP(Fe) (Co-Fe NDs), the peroxidase-like activity of the prepared bimetallic Co-Fe NDs was almost tripled. Consequently, the bimetallic Co-Fe NDs can highly efficiently catalyze the lower-concentration H2O2 into reactive oxygen species (ROS), resulting in a favorable antibacterial effect against methicillin-resistant Staphylococcus aureus (MRSA). Meanwhile, Co-Fe NDs can effectively promote wound healing and water environment disinfection with good biocompatibility. This work reveals the potential of a zero-dimensional bimetallic MOF-based nanozyme in resisting drug-resistant bacteria and holds great promise for future clinical and environmental applications.
4 citations
References
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TL;DR: Clustered regularly interspaced short palindromic repeats (CRISPR) form peculiar genetic loci, which provide acquired immunity against viruses and plasmids by targeting nucleic acid in a sequence-specific manner.
Abstract: Microbes rely on diverse defense mechanisms that allow them to withstand viral predation and exposure to invading nucleic acid. In many Bacteria and most Archaea, clustered regularly interspaced short palindromic repeats (CRISPR) form peculiar genetic loci, which provide acquired immunity against viruses and plasmids by targeting nucleic acid in a sequence-specific manner. These hypervariable loci take up genetic material from invasive elements and build up inheritable DNA-encoded immunity over time. Conversely, viruses have devised mutational escape strategies that allow them to circumvent the CRISPR/Cas system, albeit at a cost. CRISPR features may be exploited for typing purposes, epidemiological studies, host-virus ecological surveys, building specific immunity against undesirable genetic elements, and enhancing viral resistance in domesticated microbes.
2,193 citations
TL;DR: It is shown that RNA-guided DNA binding unleashes indiscriminate single-stranded DNA cleavage activity by Cas12a that completely degrades ssDNA molecules, which is also a property of other type V CRISPR-Cas12 enzymes.
Abstract: CRISPR-Cas12a (Cpf1) proteins are RNA-guided enzymes that bind and cut DNA as components of bacterial adaptive immune systems Like CRISPR-Cas9, Cas12a has been harnessed for genome editing on the basis of its ability to generate targeted, double-stranded DNA breaks Here we show that RNA-guided DNA binding unleashes indiscriminate single-stranded DNA (ssDNA) cleavage activity by Cas12a that completely degrades ssDNA molecules We find that target-activated, nonspecific single-stranded deoxyribonuclease (ssDNase) cleavage is also a property of other type V CRISPR-Cas12 enzymes By combining Cas12a ssDNase activation with isothermal amplification, we create a method termed DNA endonuclease-targeted CRISPR trans reporter (DETECTR), which achieves attomolar sensitivity for DNA detection DETECTR enables rapid and specific detection of human papillomavirus in patient samples, thereby providing a simple platform for molecular diagnostics
1,989 citations
TL;DR: A graphene oxide (GO)‐based multicolor fluorescent DNA nanoprobe that allows rapid, sensitive, and selective detection of DNA targets in homogeneous solution by exploiting interactions between GO and DNA molecules is reported.
Abstract: Coupling nanomaterials with biomolecular recognition events represents a new direction in nanotechnology toward the development of novel molecular diagnostic tools. Here a graphene oxide (GO)-based multicolor fluorescent DNA nanoprobe that allows rapid, sensitive, and selective detection of DNA targets in homogeneous solution by exploiting interactions between GO and DNA molecules is reported. Because of the extraordinarily high quenching efficiency of GO, the fluorescent ssDNA probe exhibits minimal background fluorescence, while strong emission is observed when it forms a double helix with the specific targets, leading to a high signal-to-background ratio. Importantly, the large planar surface of GO allows simultaneous quenching of multiple DNA probes labeled with different dyes, leading to a multicolor sensor for the detection of multiple DNA targets in the same solution. It is also demonstrated that this GO-based sensing platform is suitable for the detection of a range of analytes when complemented with the use of functional DNA structures.
1,302 citations
TL;DR: The Cu-TCPP nanosheet-based sensor shows excellent fluorescent sensing performance and is used for the simultaneous detection of multiple DNA targets.
Abstract: A facile surfactant-assisted bottom-up synthetic method to prepare a series of freestanding ultrathin 2D M-TCPP (M = Zn, Cu, Cd or Co, TCPP = tetrakis(4-carboxyphenyl)porphyrin) nanosheets with a thickness of sub-10 nm is developed. As a proof-of-concept application, some of them are successfully used as new platforms for DNA detection. The Cu-TCPP nanosheet-based sensor shows excellent fluorescent sensing performance and is used for the simultaneous detection of multiple DNA targets.
851 citations
TL;DR: In this article, a review of various kinds of quenching mechanisms of CDs (including static, dynamic, FRET, photo-induced electron transfer, Dexter energy transfer, and inner filter effect) is presented.
Abstract: Carbon dots (CDs) possess unique optical properties such as tunable photoluminescence (PL) and excitation dependent multicolor emission. The quenching and recovery of the fluorescence of CDs can be utilized for detecting analytes. The PL mechanisms of CDs have been discussed in previous articles, but the quenching mechanisms of CDs have not been summarized so far. Quenching mechanisms include static quenching, dynamic quenching, Forster resonance energy transfer (FRET), photoinduced electron transfer (PET), surface energy transfer (SET), Dexter energy transfer (DET) and inner filter effect (IFE). Following an introduction, the review (with 88 refs.) first summarizes the various kinds of quenching mechanisms of CDs (including static quenching, dynamic quenching, FRET, PET and IFE), the principles of these quenching mechanisms, and the methods of distinguishing these quenching mechanisms. This is followed by an overview on applications of the various quenching mechanisms in detection and imaging.
790 citations