CRISPR/Cas-powered nanobiosensors for diagnostics

Low-cost inkjet-printed nanostructured biosensor based on CRISPR/Cas12a system for pathogen detection

The escalating global incidence of infectious diseases caused by pathogenic bacteria, especially in developing countries, emphasises the urgent need for rapid and portable pathogen detection devices. This study introduces a sensitive and specific electrochemical biosensing platform utilising cost-effective electrodes fabricated by inkjet-printing gold and silver nanoparticles on a plastic substrate. The biosensor exploits the CRISPR/Cas12a system for detecting a specific DNA sequence selected from the genome of the target pathogen. Upon detection, the trans-activity of Cas12a/gRNA is triggered, leading to the cleavage of rationally designed single-strand DNA reporters (linear and hairpin) labelled with methylene blue (ssDNA-MB) and bound to the electrode surface. In principle, this sensing mechanism can be adapted to any bacterium by choosing a proper guide RNA to target a specific sequence of its DNA. The biosensor's performance was assessed for two representative pathogens (a Gram-negative, Escherichia coli, and a Gram-positive, Staphylococcus aureus), and results obtained with inkjet-printed gold electrodes were compared with those obtained by commercial screen-printed gold electrodes. Our results show that the use of inkjet-printed nanostructured gold electrodes, which provide a large surface area, in combination with the use of hairpin reporters containing a poly-T loop can increase the sensitivity of the assay corresponding to a signal variation of 86%. DNA targets amplified from various clinically isolated bacteria, have been tested and demonstrate the potential of the proposed platform for point-of-need applications.

A TdT-driven amplification loop increases CRISPR-Cas12a DNA detection levels

Recent findings on CRISPR-Cas enzymes with collateral DNAse/RNAse activity have led to new and innovative methods for pathogen detection. However, many CRISPR-Cas assays necessitate DNA pre-amplification to boost sensitivity, restricting their utility for point-of-care applications. Achieving higher sensitivity without DNA pre-amplification presents a significant challenge. In this study, we introduce a Terminal deoxynucleotidyl Transferase (TdT)-based amplification loop, creating a positive feedback mechanism within the CRISPR-Cas12a pathogen detection system. Upon recognizing pathogenic target DNA, Cas12a triggers trans-cleavage of a FRET reporter and a specific enhancer molecule oligonucleotide, indicated by the acronym POISER (Partial Or Incomplete Sites for crRNA recognition). POISER comprises half of a CRISPR-RNA recognition site, which is subsequently elongated by TdT enzymatic activity. This process, involving pathogen recognition-induced Cas12a cleavage and TdT elongation, results in a novel single-stranded DNA target. This target can subsequently be recognized by a POISER-specific crRNA, activating more Cas12a enzymes. Our study demonstrates that these POISER-cycles enhance the signal strength in fluorescent-based CRISPR-Cas12a assays. Although further refinement is desirable, POISER holds promise as a valuable tool for the detection of pathogens in point-of-care testing, surveillance, and environmental monitoring.

Coupling Exponential to Linear Amplification for Endpoint Quantitative Analysis

Exponential DNA amplification techniques are fundamental in ultrasensitive molecular diagnostics. These systems offer a wide dynamic range, but the quantification requires real-time monitoring of the amplification reaction. Linear amplification schemes, despite their limited sensitivity, can achieve quantitative measurement from a single end-point readout, suitable for low-cost, point-of-care, or massive testing. Reconciling the sensitivity of exponential amplification with the simplicity of end-point readout would thus break through a major design dilemma and open a route to a new generation of massively scalable quantitative bioassays. Here a hybrid nucleic acid-based circuit design is introduced to compute a logarithmic function, therefore providing a wide dynamic range based on a single end-point measurement. CELIA (Coupling Exponential amplification reaction to LInear Amplification) exploits a versatile biochemical circuit architecture to couple a tunable linear amplification stage - optionally embedding an inverter function - downstream of an exponential module in a one-pot format. Applied to the detection of microRNAs, CELIA provides a limit of detection in the femtomolar range and a dynamic range of six decades. This isothermal approach bypasses thermocyclers without compromising sensitivity, thereby opening the way to applications in various diagnostic assays, and providing a simplified, cost-efficient, and high throughput solution for quantitative nucleic acid analysis.

Functional analysis of single enzymes combining programmable molecular circuits with droplet-based microfluidics

The analysis of proteins at the single-molecule level reveals heterogeneous behaviours that are masked in ensemble-averaged techniques. The digital quantification of enzymes traditionally involves the observation and counting of single molecules partitioned into microcompartments via the conversion of a profluorescent substrate. This strategy, based on linear signal amplification, is limited to a few enzymes with sufficiently high turnover rate. Here we show that combining the sensitivity of an exponential molecular amplifier with the modularity of DNA-enzyme circuits and droplet readout makes it possible to specifically detect, at the single-molecule level, virtually any D(R)NA-related enzymatic activity. This strategy, denoted digital PUMA (Programmable Ultrasensitive Molecular Amplifier), is validated for more than a dozen different enzymes, including many with slow catalytic rate, and down to the extreme limit of apparent single turnover for Streptococcus pyogenes Cas9. Digital counting uniquely yields absolute molar quantification and reveals a large fraction of inactive catalysts in all tested commercial preparations. By monitoring the amplification reaction from single enzyme molecules in real time, we also extract the distribution of activity among the catalyst population, revealing alternative inactivation pathways under various stresses. Our approach dramatically expands the number of enzymes that can benefit from quantification and functional analysis at single-molecule resolution. We anticipate digital PUMA will serve as a versatile framework for accurate enzyme quantification in diagnosis or biotechnological applications. These digital assays may also be utilized to study the origin of protein functional heterogeneity.

Development of visual detection of African swine fever virus using CRISPR/LwCas13a lateral flow strip based on structural protein gene D117L

African swine fever virus (ASFV) is a large double stranded DNA arbovirus that is highly contagious and seriously endangers domestic and wild pigs. In the past decade, African swine fever (ASF) has spread in many countries in the Caucasus, Russian Federation, Eastern Europe and Asia, causing significant losses to the pig industry. At present, there is a lack of effective vaccine and treatment for ASF. Therefore, the rapid and accurate detection is crucial for ASF prevention and control. In this study, we have developed a portable lateral flow strip (LFS) detection mediated by recombinase polymerase amplification (RPA) and CRISPR/LwCas13a, which is performed at 37 ℃ and visualized by eyes without the need for complex instruments. This RPA-LwCas13a-LFS is based on the ASFV structural protein p17 gene (D117L), with a detection sensitivity up to 2 gene copies. This method is highly specific and has no cross reactivity to 7 other pig viruses. In the detection of two batches of 100 clinical samples, the p17 (D117L) RPA-LwCas13a-LFS had 100% coincidence with conventional quantitative PCR (qPCR). These findings demonstrate the potential of this simple, rapid, sensitive, and specific ASFV detection method for on-site ASFV detection.

A supersensitive electrochemical sensor based on RCA amplification-assisted "silver chain"-linked gold interdigital electrodes and CRISPR/Cas9 for the detection of Staphylococcus aureus in food

With the rising emphasis on food safety, technology to rapidly identify Staphylococcus aureus (S. aureus) is of great significance. Herein, we developed a novel electrochemical biosensor based on the CRISPR/Cas9 system and rolling circle amplification (RCA)-assisted "silver chain"-linked gold interdigital electrodes (Au-IDE). This sensor utilizes RCA to create DNA long chains that span the Au-IDE, and CRISPR/Cas9 as a recognition component to recognize capture/target dsDNA. Additionally, we used silver staining technology to improve detection sensitivity. Then, we detected S. aureus through impedance changes that occurred when the silver chain between the Au-IDE was connected or broke, with a limit of detection (LOD) of 7 CFU/mL and a detection time of 1.5 h. Lastly, we successfully employed this sensor to detect S. aureus in real food samples, making it a promising tool for food monitoring.

Signal amplification strategy of DNA self-assembled biosensor and typical applications in pathogenic microorganism detection

Biosensors have emerged as ideal analytical devices for various bio-applications owing to their low cost, convenience, and portability, which offer great potential for improving global healthcare. DNA self-assembly techniques have been enriched with the development of innovative amplification strategies, such as dispersion-to-localization of catalytic hairpin assembly, and dumbbell hybridization chain reaction, which hold great significance for building biosensors capable of realizing sensitive, rapid and multiplexed detection of pathogenic microorganisms. Here, focusing primarily on the signal amplification strategies based on DNA self-assembly, we concisely summarized the strengths and weaknesses of diverse isothermal nucleic acid amplification techniques. Subsequently, both single-layer and cascade amplification strategies based on traditional catalytic hairpin assembly and hybridization chain reaction were critically explored. Furthermore, a comprehensive overview of the recent advances in DNA self-assembled biosensors for the detection of pathogenic microorganisms is presented to summarize methods for biorecognition and signal amplification. Finally, a brief discussion is provided about the current challenges and future directions of DNA self-assembled biosensors.

CRISPR/Cas systems combined with DNA nanostructures for biomedical applications

DNA nanostructures are easy to design and construct, have good biocompatibility, and show great potential in biosensing and drug delivery. Numerous distinctive and versatile DNA nanostructures have been developed and explored for biomedical applications. In addition to DNA nanostructures that are completely assembled from DNA, composite DNA nanostructures obtained by combining DNA with other organic or inorganic materials are also widely used in related research. The CRISPR/Cas system has attracted great attention as a powerful gene editing technology and is also widely used in biomedical diagnosis. Many researchers are committed to exploring new possibilities by combining DNA nanostructures with CRISPR/Cas systems. These explorations provide support for the development of new detection methods and cargo delivery pathways, provide inspiration for improving relevant gene editing platforms, and further expand the application scope of DNA nanostructures and CRISPR/Cas systems. This paper mainly reviews the design principles and biomedical applications of CRISPR/Cas combined with DNA nanostructures based on the types of DNA nanostructures. Finally, the application status, challenges and development prospects of CRISPR/Cas combined with DNA nanostructures in detection and delivery are summarized. It is expected that this review will enable researchers to better understand the current state of the field and provide insights into the application of CRISPR/Cas systems and the development of DNA nanostructures.

Biomedical applications of engineered heparin-based materials

Heparin is a negatively charged polysaccharide with various chain lengths and a hydrophilic backbone. Due to its fascinating chemical and physical properties, nontoxicity, biocompatibility, and biodegradability, heparin has been extensively used in different fields of medicine, such as cardiovascular and hematology. This review highlights recent and future advancements in designing materials based on heparin for various biomedical applications. The physicochemical and mechanical properties, biocompatibility, toxicity, and biodegradability of heparin are discussed. In addition, the applications of heparin-based materials in various biomedical fields, such as drug/gene delivery, tissue engineering, cancer therapy, and biosensors, are reviewed. Finally, challenges, opportunities, and future perspectives in preparing heparin-based materials are summarized.

DNA Probes for Cas12a-Based Assay with Fluorescence Anisotropy Enhanced Due to Anchors and Salts

CRISPR/Cas12a is a potent biosensing tool known for its high specificity in DNA analysis. Cas12a recognizes the target DNA and acquires nuclease activity toward single-stranded DNA (ssDNA) probes. We present a straightforward and versatile approach to transforming common Cas12a-cleavable DNA probes into enhancing tools for fluorescence anisotropy (FA) measurements. Our study involved investigating 13 ssDNA probes with linear and hairpin structures, each featuring fluorescein at one end and a rotation-slowing tool (anchor) at the other. All anchors induced FA changes compared to fluorescein, ranging from 24 to 110 mr. Significant FA increases (up to 180 mr) were obtained by adding divalent metal salts (Mg2+, Ca2+, Ba2+), which influenced the rigidity and compactness of the DNA probes. The specific Cas12a-based recognition of double-stranded DNA (dsDNA) fragments of the bacterial phytopathogen Erwinia amylovora allowed us to determine the optimal set (probe structure, anchor, concentration of divalent ion) for FA-based detection. The best sensitivity was obtained using a hairpin structure with dC10 in the loop and streptavidin located near the fluorescein at the stem in the presence of 100 mM Mg2+. The detection limit of the dsDNA target was equal to 0.8 pM, which was eight times more sensitive compared to the common fluorescence-based method. The enhancing set ensured detection of single cells of E. amylovora per reaction in an analysis based on CRISPR/Cas12a with recombinase polymerase amplification. Our approach is universal and easy to implement. Combining FA with Cas12a offers enhanced sensitivity and signal reliability and could be applied to different DNA and RNA analytes.

CRISPR-powered optothermal nanotweezers: Diverse bio-nanoparticle manipulation and single nucleotide identification

Optothermal nanotweezers have emerged as an innovative optical manipulation technique in the past decade, which revolutionized classical optical manipulation by efficiently capturing a broader range of nanoparticles. However, the optothermal temperature field was merely employed for in-situ manipulation of nanoparticles, its potential for identifying bio-nanoparticles remains largely untapped. Hence, based on the synergistic effect of optothermal manipulation and CRIPSR-based bio-detection, we developed CRISPR-powered optothermal nanotweezers (CRONT). Specifically, by harnessing diffusiophoresis and thermo-osmotic flows near the substrate upon optothermal excitation, we successfully trapped and enriched DNA functionalized gold nanoparticles, CRISPR-associated proteins, as well as DNA strands. Remarkably, we built an optothermal scheme for enhancing CRISPR-based single-nucleotide polymorphism (SNP) detection at single molecule level, while also introducing a novel CRISPR methodology for observing nucleotide cleavage. Therefore, this innovative approach has endowed optical tweezers with DNA identification ability in aqueous solution which was unattainable before. With its high specificity and feasibility for in-situ bio-nanoparticle manipulation and identification, CRONT will become a universal tool in point-of-care diagnosis, biophotonics, and bio-nanotechnology.

CRISPR/Cas and Argonaute-Based Biosensors for Pathogen Detection

Over the past few decades, pathogens have posed a threat to human security, and rapid identification of pathogens should be one of the ideal methods to prevent major public health security outbreaks. Therefore, there is an urgent need for highly sensitive and specific approaches to identify and quantify pathogens. Clustered Regularly Interspaced Short Palindromic Repeats CRISPR/Cas systems and Argonaute (Ago) belong to the Microbial Defense Systems (MDS). The guided, programmable, and targeted activation of nucleases by both of them is leading the way to a new generation of pathogens detection. We compare these two nucleases in terms of similarities and differences. In addition, we discuss future challenges and prospects for the development of the CRISPR/Cas systems and Argonaute (Ago) biosensors, especially electrochemical biosensors. This review is expected to afford researchers entering this multidisciplinary field useful guidance and to provide inspiration for the development of more innovative electrochemical biosensors for pathogens detection.

Electrochemical Affinity Biosensors: Pervasive Devices with Exciting Alliances and Horizons Ahead

Electrochemical affinity biosensors are evolving at breakneck speed, strengthening and colonizing more and more niches and drawing unimaginable roadmaps that increasingly make them protagonists of our daily lives. They achieve this by combining their intrinsic attributes with those acquired by leveraging the significant advances that occurred in (nano)materials technology, bio(nano)materials and nature-inspired receptors, gene editing and amplification technologies, and signal detection and processing techniques. The aim of this Perspective is to provide, with the support of recent representative and illustrative literature, an updated and critical view of the repertoire of opportunities, innovations, and applications offered by electrochemical affinity biosensors fueled by the key alliances indicated. In addition, the imminent challenges that these biodevices must face and the new directions in which they are envisioned as key players are discussed.

Aerosol Jet Printing-Enabled Dual-Function Electrochemical and Colorimetric Biosensor for SARS-CoV-2 Detection

An aerosol jet printing-enabled dual-function biosensor for the sensitive detection of pathogens using SARS-CoV-2 RNA as an example has been developed. A CRISPR-Cas13:guide-RNA complex is activated in the presence of a target RNA, leading to the collateral trans-cleavage of ssRNA probes that contain a horseradish peroxidase (HRP) tag. This, in turn, catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by HRP, resulting in a color change and electrochemical signal change. The colorimetric and electrochemical sensing protocol does not require complicated target amplification and probe immobilization and exhibits a detection sensitivity in the femtomolar range. Additionally, our biosensor demonstrates a wide dynamic range of 5 orders of magnitude. This low-cost aerosol inkjet printing technique allows for an amplification-free and integrated dual-function biosensor platform, which operates at physiological temperature and is designed for simple, rapid, and accurate point-of-care (POC) diagnostics in either low-resource settings or hospitals.

CRISPR/Cas-Based Diagnostics in Agricultural Applications

Pests and disease-causing pathogens frequently impede agricultural production. An early and efficient diagnostic tool is crucial for effective disease management. Clustered regularly interspaced short palindromic repeats (CRISPR) and the CRISPR-associated protein (Cas) have recently been harnessed to develop diagnostic tools. The CRISPR/Cas system, composed of the Cas endonuclease and guide RNA, enables precise identification and cleavage of the target nucleic acids. The inherent sensitivity, high specificity, and rapid assay time of the CRISPR/Cas system make it an effective alternative for diagnosing plant pathogens and identifying genetically modified crops. Furthermore, its potential for multiplexing and suitability for point-of-care testing at the field level provide advantages over traditional diagnostic systems such as RT-PCR, LAMP, and NGS. In this review, we discuss the recent developments in CRISPR/Cas based diagnostics and their implications in various agricultural applications. We have also emphasized the major challenges with possible solutions and provided insights into future perspectives and potential applications of the CRISPR/Cas system in agriculture.

A SERS-signalled, CRISPR/Cas-powered bioassay for amplification-free and anti-interference detection of SARS-CoV-2 in foods and environmental samples using a single tube-in-tube vessel

The pandemic of COVID-19 creates an imperative need for sensitive and portable detection of SARS-CoV-2. We devised a SERS-read, CRISPR/Cas-powered nanobioassay, termed as OVER-SARS-CoV-2 (One-Vessel Enhanced RNA test on SARS-CoV-2), which enabled supersensitive, ultrafast, accurate and portable detection of SARS-CoV-2 in a single vessel in an amplification-free and anti-interference manner. The SERS nanoprobes were constructed by conjugating gold nanoparticles with Raman reporting molecular and single-stranded DNA (ssDNA) probes, whose aggregation-to-dispersion changes can be finely tuned by target-activated Cas12a though trans-cleavage of linker ssDNA. As such, the nucleic acid signals could be dexterously converted and amplified to SERS signals. By customizing an ingenious vessel, the steps of RNA reverse transcription, Cas12a trans-cleavage and SERS nanoprobes crosslinking can be integrated into a single and disposal vessel. It was proved that our proposed nanobioassay was able to detect SARS-CoV-2 as low as 200 copies/mL without any pre-amplification within 45 min. In addition, the proposed nanobioassay was confirmed by clinical swab samples and challenged for SARS-CoV-2 detection in simulated complex environmental and food samples. This work enriches the arsenal of CRISPR-based diagnostics (CRISPR-Dx) and provides a novel and robust platform for SARS-CoV-2 decentralized detection, which can be put into practice in the near future.

"Lollipop" particle counting immunoassay based on antigen-powered CRISPR-Cas12a dual signal amplification for the sensitive detection of deoxynivalenol in the environment and food samples

Deoxynivalenol is one of the most widely distributed mycotoxins in cereals and poses tremendous threats to the agricultural environment and public health. Therefore, it is particularly important to develop sensitive and interference-resistant deoxynivalenol analysis methods. Here, we establish a "Lollipop" particle counting immunoassay (LPCI) based on antigen-powered CRISPR-Cas12a dual signal amplification. LPCI achieves high sensitivity and accuracy through antigen-powered CRISPR-Cas dual signal amplification combined with particle counting immunoassay. This strategy not only broadens the applicability of the CRISPR-Cas system in the field of non-nucleic acid target detection; it also improves the sensitivity of particle counting immunoassay. The introduction of a polystyrene "lollipop" immunoassay carrier further enables efficiently simultaneous pre-treatment of multiple samples and overcomes complex matrix interference in real samples. The linear detection range of LPCI for deoxynivalenol was 0.1-500 ng/mL with a detection limit of 0.061 ng/mL. The platform greatly broadens the scope of the CRISPR-Cas sensor for the detection of non-nucleic acid hazards in the environment and food samples.

Using time-shared scanning optical tweezers assisted two-photon fluorescence imaging to establish a versatile CRISPR/Cas12a-mediated biosensor

Based on the admirable precision to identify target nucleic acids and the particular trans-cleavage feature, CRISPR/Cas12a system is a useful means to further improve the sensing accuracy and the design flexibility of fluorescence biosensors. However, the current construction concepts still suffer from insufficient sensitivity, unsuitable for complicated real samples and limited detection species. In this work, much efforts are achieved to address these obstacles. At first, we adopt a microsphere sustained signal enrichment, under which a home-made time-shared scanning optical tweezers assisted fluorescence imaging is employed to guarantee a stable excitation and also realize multiflux measurement. Furthermore, by taking advantage of the low background merit of the near-infrared light excited two-photon fluorescence, a commendable anti-interference capability is endowed to operate in complex media. After utilizing a functional DNA (e.g. aptamer and DNAzyme) regulated mediation pathway to respond non-nucleic acid analytes (alpha fetal protein and Pb²⁺), the newly-established CRISPR/Cas12a-mediated fluorescence biosensor is found to display favorable assay performance. More importantly, our analytical methodology can act as a versatile and reliable toolbox in various applications such as disease diagnosis and environmental analysis, propelling the development of CRISPR system in biosensing field.

Aerosol Jet Printing Enabled Dual-Function Electrochemical and Colorimetric Biosensor for SARS-CoV-2 Detection

An aerosol jet printing enabled dual-function biosensor for the sensitive detection of pathogens using SARS-CoV-2 RNA as an example has been developed. A CRISPR-Cas13: guide-RNA complex is activated in the presence of a target RNA, leading to the collateral trans-cleavage of ssRNA probes that contain a horseradish peroxidase (HRP) tag. This, in turn, catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by HRP, resulting in a color change and electrochemical signal change. The colorimetric and electrochemical sensing protocol does not require complicated target amplification and probe immobilization and exhibits a detection sensitivity in the femtomolar range. Additionally, our biosensor demonstrates a wide dynamic range of 5 orders of magnitude. This low-cost aerosol inkjet printing technique allows for an amplification-free and integrated dual-function biosensor platform, which operates at physiological temperature and is designed for simple, rapid, and accurate point-of-care (POC) diagnostics in either low-resource settings or hospitals.

Electrochemical biosensors for analysis of DNA point mutations in cancer research

Cancer is a genetic disease induced by mutations in DNA, in particular point mutations in important driver genes that lead to protein malfunctioning and ultimately to tumorigenesis. Screening for the most common DNA point mutations, especially in such genes as TP53, BRCA1 and BRCA2, EGFR, KRAS, or BRAF, is crucial to determine predisposition risk for cancer or to predict response to therapy. In this review, we briefly depict how these genes are involved in cancer, followed by a description of the most common techniques routinely applied for their analysis, including high-throughput next-generation sequencing technology and less expensive low-throughput options, such as real-time PCR, restriction fragment length polymorphism, or high resolution melting analysis. We then introduce benefits of electrochemical biosensors as interesting alternatives to the standard methods in terms of cost, speed, and simplicity. We describe most common strategies involved in electrochemical biosensing of point mutations, relying mostly on PCR or isothermal amplification techniques, and critically discuss major challenges and obstacles that, until now, prevented their more widespread application in clinical settings.

Comparison of Biosensing Methods Based on Different Isothermal Amplification Strategies: A Case Study with Erwinia amylovora

Isothermal amplifications allow for the highly sensitive detection of nucleic acids, bypassing the use of instrumental thermal cycling. This work aimed to carry out an experimental comparison of the four most promising techniques: recombinase polymerase amplification (RPA) and loop-mediated isothermal amplification (LAMP) coupled with lateral flow test or coupled with additional amplification based on CRISPR/Cas12a resulting from the fluorescence of the Cas12a-cleaved probe. To compare the four amplification techniques, we chose the bacterial phytopathogen Erwinia amylovora (causative agent of fire blight), which has a quarantine significance in many countries and possesses a serious threat to agriculture. Three genes were chosen as the targets and primers were selected for each one (two for RPA and six for LAMP). They were functionalized by labels (biotin, fluorescein) at the 5' ends for amplicons recognition by LFT. As a result, we developed LAMP-LFT, LAMP-CRISPR/Cas, RPA-LFT, and RPA-CRISPR/Cas for E. amylovora detection. The detection limit was 10⁴ CFU/mL for LAMP-LFT, 10³ CFU/mL for LAMP-CRISPR/Cas, and 10² CFU/mL for RPA-LFT and RPA-CRISPR/Cas. The results of four developed test systems were verified by qPCR on a panel of real samples. The developed assays based on RPA, LAMP, CRISPR/Cas12a, and LFT are rapid (30-55 min), user-friendly, and highly sensitive for E. amylovora detection. All proposed detection methods can be applied to fire blight diagnosis and effective management of this disease.

CRISPR-Cas based molecular diagnostics for foodborne pathogens

Foodborne pathogenic infection has brought multifaceted issues to human life, leading to an urgent demand for advanced detection technologies. CRISPR/Cas-based biosensors have the potential to address various challenges that exist in conventional assays such as insensitivity, long turnaround time and complex pretreatments. In this perspective, we review the relevant strategies of CRISPR/Cas-assisted diagnostics on foodborne pathogens, focusing on biosensing platforms for foodborne pathogens based on fluorescence, colorimetric, (electro)chemiluminescence, electrochemical, and surface-enhanced Raman scattering detection. It summarizes their detection principles by the clarification of foodborne pathogenic bacteria, fungi, and viruses. Finally, we discuss the current challenges or technical barriers of these methods against broad application, and put forward alternative solutions to improve CRISPR/Cas potential for food safety.

Selenium-based nanomaterials for biosensing applications

The unique chemical and physical features of nanomaterials make them ideal for developing new and better sensing devices, particularly biosensors. Various types of nanoparticles, including metal, oxide, and semiconductor nanostructures, have been utilized to manufacture biosensors, and each kind of nanoparticle plays a unique role in the sensing system. Nanoparticles provide critical roles such as immobilizing biomolecules, catalyzing electrochemical processes, enhancing electron transport between electrode surfaces and proteins, identifying biomolecules, and even functioning as the reactant for the catalytic reaction. Among all the potential nanosystems to be used in biosensors, selenium nanoparticle (SeNP) features have sparked a growing interest in their use in bridging biological recognition events and signal transduction, as well as in developing biosensing devices with novel applications for identification, quantification, and study of different analytes of biological relevance. The optical, physical, and chemical characteristics of differently shaped SeNPs opened up a world of possibilities for developing biosensors of biomedical interest. The outstanding biocompatibility, conductivity, catalytic characteristics, high surface-to-volume ratio, and high density of SeNPs have enabled their widespread use in developing electrochemical biosensors with superior analytical performance compared to other designs of biosensors. This review summarizes recent and ongoing advances, current challenges, and future research perspectives on real-world applications of Se-based nanobiosensors to detect biologically relevant analytes such as hydrogen peroxide, heavy metals, or glucose. Due to the superior properties and multifunctionality of Se-NPs biosensors, these structures can open up considerable new horizons in the future of healthcare and medicine.

PrimedSherlock: a tool for rapid design of highly specific CRISPR-Cas12 crRNAs

Background

CRISPR-Cas based diagnostic assays provide a portable solution which bridges the benefits of qRT-PCR and serological assays in terms of portability, specificity and ease of use. CRISPR-Cas assays are rapidly fieldable, specific and have been rigorously validated against a number of targets, including HIV and vector-borne pathogens. Recently, CRISPR-Cas12 and CRISPR-Cas13 diagnostic assays have been granted FDA approval for the detection of SARS-CoV-2. A critical step in utilizing this technology requires the design of highly-specific and efficient CRISPR RNAs (crRNAs) and isothermal primers. This process involves intensive manual curation and stringent parameters for design in order to minimize off-target detection while also preserving detection across divergent strains. As such, a single, streamlined bioinformatics platform for rapidly designing crRNAs for use with the CRISPR-Cas12 platform is needed. Here we offer PrimedSherlock, an automated, computer guided process for selecting highly-specific crRNAs and primers for targets of interest.

Results

Utilizing PrimedSherlock and publicly available databases, crRNAs were designed against a selection of Flavivirus genomes, including West Nile, Zika and all four serotypes of Dengue. Using outputs from PrimedSherlock in concert with both wildtype A.s Cas12a and Alt-R Cas12a Ultra nucleases, we demonstrated sensitive detection of nucleic acids of each respective arbovirus in in-vitro fluorescence assays. Moreover, primer and crRNA combinations facilitated the detection of their intended targets with minimal off-target background noise.

Conclusions

PrimedSherlock is a novel crRNA design tool, specific for CRISPR-Cas12 diagnostic platforms. It allows for the rapid identification of highly conserved crRNA targets from user-provided primer pairs or PrimedRPA output files. Initial testing of crRNAs against arboviruses of medical importance demonstrated a robust ability to distinguish multiple strains by exploiting polymorphisms within otherwise highly conserved genomic regions. As a freely-accessible software package, PrimedSherlock could significantly increase the efficiency of CRISPR-Cas12 diagnostics. Conceptually, the portability of detection kits could also be enhanced when coupled with isothermal amplification technologies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04968-5.

Point-of-care CRISPR/Cas biosensing technology: A promising tool for preventing the possible COVID-19 resurgence caused by contaminated cold-chain food and packaging

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused great public health concern and has been a global threat due to its high transmissibility and morbidity. Although the SARS-CoV-2 transmission mainly relies on the person-to-person route through the respiratory droplets, the possible transmission through the contaminated cold-chain food and packaging to humans has raised widespread concerns. This review discussed the possibility of SARS-CoV-2 transmission via the contaminated cold-chain food and packaging by tracing the occurrence, the survival of SARS-CoV-2 in the contaminated cold-chain food and packaging, as well as the transmission and outbreaks related to the contaminated cold-chain food and packaging. Rapid, accurate, and reliable diagnostics of SARS-CoV-2 is of great importance for preventing and controlling the COVID-19 resurgence. Therefore, we summarized the recent advances on the emerging clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system-based biosensing technology that is promising and powerful for preventing the possible COVID-19 resurgence caused by the contaminated cold-chain food and packaging during the COVID-19 pandemic, including CRISPR/Cas system-based biosensors and their integration with portable devices (e.g., smartphone, lateral flow assays, microfluidic chips, and nanopores). Impressively, this review not only provided an insight on the possibility of SARS-CoV-2 transmission through the food supply chain, but also proposed the future opportunities and challenges on the development of CRISPR/Cas system-based detection methods for the diagnosis of SARS-CoV-2.

CRISPR/Cas Systems-Inspired Nano/Biosensors for Detecting Infectious Viruses and Pathogenic Bacteria

Infectious pathogens cause severe human illnesses and great deaths per year worldwide. Rapid, sensitive, and accurate detection of pathogens is of great importance for preventing infectious diseases caused by pathogens and optimizing medical healthcare systems. Inspired by a microbial defense system (i.e., CRISPR/ CRISPR-associated proteins (Cas) system, an adaptive immune system for protecting microorganisms from being attacked by invading species), a great many new biosensors have been successfully developed and widely applied in the detection of infectious viruses and pathogenic bacteria. Moreover, advanced nanotechnologies have also been integrated into these biosensors to improve their detection stability, sensitivity, and accuracy. In this review, the recent advance in CRISPR/Cas systems-based nano/biosensors and their applications in the detection of infectious viruses and pathogenic bacteria are comprehensively reviewed. First of all, the categories and working principles of CRISPR/Cas systems for establishing the nano/biosensors are simply introduced. Then, the design and construction of CRISPR/Cas systems-based nano/biosensors are comprehensively discussed. In the end, attentions are focused on the applications of CRISPR/Cas systems-based nano/biosensors in the detection of infectious viruses and pathogenic bacteria. Impressively, the remaining opportunities and challenges for the further design and development of CRISPR/Cas system-based nano/biosensors and their promising applications are proposed.

Omicron variant: Current insights and future directions

The global COVID-19 outbreak has returned with the identification of the SARS-CoV-2 Omicron variant (B.1.1.529) after appearing to be persistently spreading for the more than past two years. In comparison to prior SARS-CoV-2 variants, this new variant revealed a significant amount of mutation. This novel variety may have a greater rate of transmissibility which might impede the effectiveness of current diagnostic equipment as well as vaccination efficacy and also impede immunotherapies (Antibody / monoclonal antibody based). WHO designated B.1.1.529 as a variant of concern on November 26, 2021, identified as Omicron. The Omicron variant transmission method and severity, on the other hand, are well defined. The global spread of Omicron, which has now seized many nations, has resulted in numerous speculations regarding its origin and degree of infectivity. The following sections will go over its potential for transmission, omicron structure, and impact on COVID-19 vaccines, how it is different from delta variant and diagnostics.

Research progress of CRISPR-based biosensors and bioassays for molecular diagnosis

CRISPR/Cas technology originated from the immune mechanism of archaea and bacteria and was awarded the Nobel Prize in Chemistry in 2020 for its success in gene editing. Molecular diagnostics is highly valued globally for its development as a new generation of diagnostic technology. An increasing number of studies have shown that CRISPR/Cas technology can be integrated with biosensors and bioassays for molecular diagnostics. CRISPR-based detection has attracted much attention as highly specific and sensitive sensors with easily programmable and device-independent capabilities. The nucleic acid-based detection approach is one of the most sensitive and specific diagnostic methods. With further research, it holds promise for detecting other biomarkers such as small molecules and proteins. Therefore, it is worthwhile to explore the prospects of CRISPR technology in biosensing and summarize its application strategies in molecular diagnostics. This review provides a synopsis of CRISPR biosensing strategies and recent advances from nucleic acids to other non-nucleic small molecules or analytes such as proteins and presents the challenges and perspectives of CRISPR biosensors and bioassays.

CRISPR-Cas-based detection for food safety problems: Current status, challenges, and opportunities

Food safety is one of the biggest public issues occurring around the world. Microbiological, chemical, and physical hazards can lead to food safety issues, which may occur at all stages of the supply chain. In order to tackle food safety issues and safeguard consumer health, rapid, accurate, specific, and field-deployable detection methods meeting diverse requirements are one of the imperative measures for food safety assurance. CRISPR-Cas system, a newly emerging technology, has been successfully repurposed in biosensing and has demonstrated huge potential to establish conceptually novel detection methods with high sensitivity and specificity. This review focuses on CRISPR-Cas-based detection and its current status and huge potential specifically for food safety inspection. We firstly illustrate the pending problems in food safety and summarize the popular detection methods. We then describe the potential applications of CRISPR-Cas-based detection in food safety inspection. Finally, the challenges and futuristic opportunities are proposed and discussed. Generally speaking, the current food safety detection methods are still unsatisfactory in some ways such as being time-consuming, displaying unmet sensitivity and specificity standards, and there is a comparative paucity of multiplexed testing and POCT. Recent studies have shown that CRISPR-Cas-based biosensing is an innovative and fast-expanding technology, which could make up for the shortcomings of the existing methods or even replace them. To sum up, the implementation of CRISPR-Cas and the integration of CRISPR-Cas with other techniques is promising and desirable, which is expected to provide "customized" and "smart" detection methods for food safety inspection in the coming future.

OMICRON: Virology, immunopathogenesis, and laboratory diagnosis

Since its emersion, coronavirus disease 2019 (COVID-19) has been a significant global dilemma. Several mutations in the severe acute respiratory virus (SARS-Co-2) genome has given rise to different variants with various levels of transmissibility, severity and mortality. Up until November 2021, the variants of concern declared by the World Health Organization were Alpha, Beta, Delta and Gamma. Since then, a novel variant named Omicron (B.1.1.529) has been developed. BA.1, BA.1.1, BA.2 and BA.3 are four known subvariants of Omicron. The Omicron variant involves new mutations in its spike protein, most of which are in its receptor binding site, and increase its transmissibility and decrease its antibody and vaccine response. Understanding the virology and mutations of Omicron is necessary for developing diagnostic and therapeutic methods. Moreover, important issues, such as the risk of re-infection, the response to different kinds of vaccines, the need for a booster vaccine dose and the increased risk of Omicron infection in pediatrics, need to be addressed. In this article, we provide an overview of the biological and immunopathological properties of Omicron and its subvariants, its clinical signs and symptoms, Omicron and pediatrics, vaccines against Omicron, re-infection with Omicron, diagnostic approaches and specific challenges of Omicron in the successful control and management of the rapid global spread of this variant.

BSA-PEI Nanoparticle Mediated Efficient Delivery of CRISPR/Cas9 into MDA-MB-231 Cells

The discovery of bacterial-derived Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system has revolutionized genome engineering and gene therapy due to its wide range of applications. One of the major challenging issues in CRISPR/Cas system is the lack of an efficient, safe, and clinically suitable delivery of the system’s components into target cells. Here, we describe the development of polyethylenimine coated-bovine serum albumin nanoparticles (BSA-PEI NPs) for efficient delivery of CRISPR/Cas9 system in both DNA (px458 plasmid) and ribonucleoprotein (RNP) forms into MDA-MB-231 human breast cancer cell line. Our data showed that synthesized BSA-PEI (BP) NPs delivered plasmid px458 at concentrations of 0.15, 0.25, and 0.35 µg/µl with efficiencies of approximately 29.7, 54.8, and 84.1% into MDA-MB-231 cells, respectively. Our study demonstrated that Cas9/sgRNA RNP complex efficiently (~ 92.6%) delivered by BSA-PEI NPs into the same cells. Analysis of toxicity and biocompatibility of synthesized NPs on human red blood cells, MDA-MB-231 cells, and mice showed that the selected concentration (28 µg/µl) of BSA-PEI NPs for transfection had no remarkable toxicity effects. Thus, obtained results suggest BSA-PEI NPs as one of the most promising carrier for delivering CRISPR/Cas9 to target cells.

A CRISPR-Cas12a-powered magnetic relaxation switching biosensor for the sensitive detection of Salmonella

Magnetic relaxation switching (MRS) biosensors are attractive in the field of food safety owing to their simplicity and high signal-to-noise ratio. But they are less in sensitivity and stability caused by the insufficient crosslinking or non-specific binding of magnetic nanoparticles (MNPs) with targets. To address this problem, the CRISPR-Cas12a system was introduced into an MRS biosensor for the first time, to precisely control the binding of two types of MNPs with sizes of 130 nm (MNP₁₃₀) and 30 nm (MNP₃₀), for the sensitive detection of Salmonella. Delicately, the biosensor was designed based on the different magnetic properties of the two sizes of MNPs. The target Salmonella activated the collateral cleavage activity of the CRISPR-Cas12a system, which inhibited the binding of the two sizes of MNPs, resulting in an increase of unbound MNP₃₀. After separating MNP₁₃₀-MNP₃₀ complexes and MNP₁₃₀ from MNP₃₀, the free MNP₃₀ left in solution acted as transverse relaxation time (T₂) signal reporters for Salmonella detection. Under optimized conditions, the CRISPR-MRS biosensor presented a limit of detection of 1.3 × 10² CFU mL^-1 for Salmonella, which is lower than most MRS biosensor analogues. It also showed satisfactory specificity and performed well in spiked chicken meat samples. This biosensing strategy not only extends the reach of the CRISPR-Cas12a system in biosensors but also offers an alternative for pathogen detection with satisfactory sensitivity.

Theragnostic application of nanoparticle and CRISPR against food-borne multi-drug resistant pathogens

Foodborne infection is one of the leading sources of infections spreading across the world. Foodborne pathogens are recognized as multidrug-resistant (MDR) pathogens posing a significant problem in the food industry and healthy consumers resulting in enhanced economic burden, and nosocomial infections. The continued search for enhanced microbial detection tools has piqued the interest of the CRISPR-Cas system and Nanoparticles. CRISPR-Cas system is present in the bacterial genome of some prokaryotes and is repurposed as a theragnostic tool against MDR pathogens. Nanoparticles and composites have also emerged as an efficient tool in theragnostic applications against MDR pathogens. The diagnostic limitations of the CRISPR-Cas system are believed to be overcome by a synergistic combination of the nanoparticles system and CRISPR-Cas using nanoparticles as vehicles. In this review, we have discussed the diagnostic application of CRISPR-Cas technologies along with their potential usage in applications like phage resistance, phage vaccination, strain typing, genome editing, and antimicrobial. we have also elucidated the antimicrobial and detection role of nanoparticles against foodborne MDR pathogens. Moreover, the novel combinatorial approach of CRISPR-Cas and nanoparticles for their synergistic effects in pathogen clearance and drug delivery vehicles has also been discussed.

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Bacterial CRISPR Cas system are repurposed as a thergodiganostic tool against MDR pathogen.

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Combinatorial approach of CRISPR-Cas and Nanoparticle is used as delivery vehicle and clearing pathogens.

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CRISPR-Cas and Nanoparticles is a tool for the food safety profiling of MDR food-borne pathogen.

Ultrasensitive CRISPR/Cas12a-Driven SERS Biosensor for On-Site Nucleic Acid Detection and Its Application to Milk Authenticity Testing

An ultrasensitive surface-enhanced Raman scattering (SERS) biosensor driven by CRISPR/Cas12a was proposed for on-site nucleic acid detection. We tactfully modified single-strand DNA (ssDNA) with a target-responsive Prussian blue (PB) nanolabel to form a probe and fastened it in the microplate. Attributed to the specific base pairing and highly efficient trans-cleavage ability of the CRISPR/Cas12a effector, precise target DNA recognition and signal amplification can be achieved, respectively. In the presence of target DNA, trans-cleavage towards the probe was activated, leading to the release of a certain number of PB nanoparticles (NPs). Then, these free PB NPs would be removed. Under alkali treatment, the breakdown of the remaining PB NPs in the microplate was triggered, producing massive ferricyanide anions (Fe(CN)₆^4-), which could exhibit a unique characteristic Raman peak that was located in the "biological Raman-silent region". By mixing the alkali-treated solution with the SERS substrate, Au@Ag core-shell NP, the concentration of the target DNA was finally exhibited as SERS signals with undisturbed background, which can be detected by a portable Raman spectrometer. Importantly, this strategy could display an ultralow detection limit of 224 aM for target DNA. Furthermore, by targeting cow milk as the adulterated ingredient in goat milk, the proposed biosensor was successfully applied to milk authenticity detection.

How Advancing are Mesoporous Silica Nanoparticles? A Comprehensive Review of the Literature

The application of mesoporous silica nanoparticles (MSNs) is ubiquitous in various sciences. MSNs possess unique features, including the diversity in manufacturing by different synthesis methods and from different sources, structure controllability, pore design capabilities, pore size tunability, nanoparticle size distribution adjustment, and the ability to create diverse functional groups on their surface. These characteristics have led to various types of MSNs as a unique system for drug delivery. In this review, first, the synthesis of MSNs by different methods via using different sources were studied. Then, the parameters affecting their physicochemical properties and functionalization have been discussed. Finally, the last decade’s novel strategies, including surface functionalization, drug delivery, and cancer treatment, based on the MSNs in drug delivery and cancer therapy have been addressed.

New Insights for Biosensing: Lessons from Microbial Defense Systems

Microorganisms have gained defense systems during the lengthy process of evolution over millions of years. Such defense systems can protect them from being attacked by invading species (e.g., CRISPR-Cas for establishing adaptive immune systems and nanopore-forming toxins as virulence factors) or enable them to adapt to different conditions (e.g., gas vesicles for achieving buoyancy control). These microorganism defense systems (MDS) have inspired the development of biosensors that have received much attention in a wide range of fields including life science research, food safety, and medical diagnosis. This Review comprehensively analyzes biosensing platforms originating from MDS for sensing and imaging biological analytes. We first describe a basic overview of MDS and MDS-inspired biosensing platforms (e.g., CRISPR-Cas systems, nanopore-forming proteins, and gas vesicles), followed by a critical discussion of their functions and properties. We then discuss several transduction mechanisms (optical, acoustic, magnetic, and electrical) involved in MDS-inspired biosensing. We further detail the applications of the MDS-inspired biosensors to detect a variety of analytes (nucleic acids, peptides, proteins, pathogens, cells, small molecules, and metal ions). In the end, we propose the key challenges and future perspectives in seeking new and improved MDS tools that can potentially lead to breakthrough discoveries in developing a new generation of biosensors with a combination of low cost; high sensitivity, accuracy, and precision; and fast detection. Overall, this Review gives a historical review of MDS, elucidates the principles of emulating MDS to develop biosensors, and analyzes the recent advancements, current challenges, and future trends in this field. It provides a unique critical analysis of emulating MDS to develop robust biosensors and discusses the design of such biosensors using elements found in MDS, showing that emulating MDS is a promising approach to conceptually advancing the design of biosensors.

SARS-CoV-2 Omicron variant: A next phase of the COVID-19 pandemic and a call to arms for system sciences and precision medicine

Since early 2020, coronavirus diseases 2019 (COVID-19) infection pandemic/endemic is constantly surprising health experts because of continuous variations in the structures of severe acute respiratory coronavirus 2 (SARS-CoV-2) in the form of newly emerged variants. Such mutations have exhibited high mortality and severity due to the newly emerged more infectious sites of SARS-CoV-2, making viral infection more transmissible, infectious, and severe. Recently, SARS-CoV-2 mutated to another variant, namely, Omicron (B.1.1.529), which is many times more transmissible and infectious than existed deadly Delta variants of the virus. This severity is closely correlated to a larger number of mutations observed in the receptor-binding domain of the spike protein of the Omicron-SARS-CoV-2. Considering severity, Omicron has been declared as variant of concerns by the World Health Organization and within days from its emergence, Omicron infection has spread globally, increased hospitalization, exhibited more severity for the young generation, invaded defense mechanism of natural immunity, not responsive to the available vaccines. Such circumstances resonated with the efficiency of available strategies established to manage COVID-19 intelligently and successfully. To explore these aspects, this perspective article carefully and critically summarizes the Omicron's origin, structure, pathogenesis, impact health along with health systems, and experts' recommendations to manage it successfully.

Doxorubicin-loaded graphene oxide nanocomposites in cancer medicine: Stimuli-responsive carriers, co-delivery and suppressing resistance

INTRODUCTION

The application of doxorubicin (DOX) in cancer therapy has been limited due to its drug resistance and poor internalization. Graphene oxide (GO) nanostructures have the capacity for DOX delivery while promoting its cytotoxicity in cancer.

AREAS COVERED

The favorable characteristics of GO nanocomposites, preparation method, and application in cancer therapy are described. Then, DOX resistance in cancer is discussed. The GO-mediated photothermal therapy and DOX delivery for cancer suppression are described. Preparation of stimuli-responsive GO nanocomposites, surface functionalization, hybrid nanoparticles, and theranostic applications are emphasized in DOX chemotherapy.

EXPERT OPINION

Graphene oxide nanoparticle-based photothermal therapy maximizes the anti-cancer activity of DOX against cancer cells. Apart from DOX delivery, GO nanomaterials are capable of loading anti-cancer agents and genetic tools to minimize drug resistance and enhance the cytolytic impact of DOX in cancer eradication. To enhance DOX accumulation in cancer cells, stimuli-responsive (redox-, light-, enzyme- and pH-sensitive) GO nanoparticles have been developed for DOX delivery. Further development of targeted delivery of DOX-loaded GO nanomaterials against cancer cells may be achieved by surface modification of polymers such as polyethylene glycol, hyaluronic acid, and chitosan. Doxorubicin-loaded GO nanoparticles have demonstrated theranostic potential for simultaneous diagnosis and therapy. Hybridization of GO with other nanocarriers such as silica and gold nanoparticles further broadens their potential anti-cancer therapy applications.

Exploring nano-enabled CRISPR-Cas-powered strategies for efficient diagnostics and treatment of infectious diseases

Biomedical researchers have subsequently been inspired the development of new approaches for precisely changing an organism's genomic DNA in order to investigate customized diagnostics and therapeutics utilizing genetic engineering techniques. Clustered Regulatory Interspaced Short Palindromic Repeats (CRISPR) is one such technique that has emerged as a safe, targeted, and effective pharmaceutical treatment against a wide range of disease-causing organisms, including bacteria, fungi, parasites, and viruses, as well as genetic abnormalities. The recent discovery of very flexible engineered nucleic acid binding proteins has changed the scientific area of genome editing in a revolutionary way. Since current genetic engineering technique relies on viral vectors, issues about immunogenicity, insertional oncogenesis, retention, and targeted delivery remain unanswered. The use of nanotechnology has the potential to improve the safety and efficacy of CRISPR/Cas9 component distribution by employing tailored polymeric nanoparticles. The combination of two (CRISPR/Cas9 and nanotechnology) offers the potential to open new therapeutic paths. Considering the benefits, demand, and constraints, the goal of this research is to acquire more about the biology of CRISPR technology, as well as aspects of selective and effective diagnostics and therapies for infectious illnesses and other metabolic disorders. This review advocated combining nanomedicine (nanomedicine) with a CRISPR/Cas enabled sensing system to perform early-stage diagnostics and selective therapy of specific infectious disorders. Such a Nano-CRISPR-powered nanomedicine and sensing system would allow for successful infectious illness control, even on a personal level. This comprehensive study also discusses the current obstacles and potential of the predicted technology.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40097-022-00472-7.

Point-of-Care Testing-The Key in the Battle against SARS-CoV-2 Pandemic

The deleterious effects of the coronavirus disease 2019 (COVID-19) pandemic urged the development of diagnostic tools to manage the spread of disease. Currently, the "gold standard" involves the use of quantitative real-time polymerase chain reaction (qRT-PCR) for SARS-CoV-2 detection. Even though it is sensitive, specific and applicable for large batches of samples, qRT-PCR is labour-intensive, time-consuming, requires trained personnel and is not available in remote settings. This review summarizes and compares the available strategies for COVID-19: serological testing, Point-of-Care Testing, nanotechnology-based approaches and biosensors. Last but not least, we address the advantages and limitations of these methods as well as perspectives in COVID-19 diagnostics. The effort is constantly focused on understanding the quickly changing landscape of available diagnostic testing of COVID-19 at the clinical levels and introducing reliable and rapid screening point of care testing. The last approach is key to aid the clinical decision-making process for infection control, enhancing an appropriate treatment strategy and prompt isolation of asymptomatic/mild cases. As a viable alternative, Point-of-Care Testing (POCT) is typically low-cost and user-friendly, hence harbouring tremendous potential for rapid COVID-19 diagnosis.