Gold-Aptamer-Nanoconstructs Engineered to Detect Conserved Enteroviral Nucleic Acid Sequences

Author(s):  
Veeren Chauhan ◽  
Mohamed M Elsutohy ◽  
C Patrick McClure ◽  
Will Irving ◽  
Neil Roddis ◽  
...  

<p>Enteroviruses are a ubiquitous mammalian pathogen that can produce mild to life-threatening disease. Bearing this in mind, we have developed a rapid, accurate and economical point-of-care biosensor that can detect a nucleic acid sequences conserved amongst 96% of all known enteroviruses. The biosensor harnesses the physicochemical properties of gold nanoparticles and aptamers to provide colourimetric, spectroscopic and lateral flow-based identification of an exclusive enteroviral RNA sequence (23 bases), which was identified through in silico screening. Aptamers were designed to demonstrate specific complementarity towards the target enteroviral RNA to produce aggregated gold-aptamer nanoconstructs. Conserved target enteroviral nucleic acid sequence (≥ 1x10<sup>-7</sup> M, ≥1.4×10<sup>-14</sup> g/mL), initiates gold-aptamer-nanoconstructs disaggregation and a signal transduction mechanism, producing a colourimetric and spectroscopic blueshift (544 nm (purple) > 524 nm (red)). Furthermore, lateral-flow-assays that utilise gold-aptamer-nanoconstructs were unaffected by contaminating human genomic DNA, demonstrated rapid detection of conserved target enteroviral nucleic acid sequence (< 60 s) and could be interpreted with a bespoke software and hardware electronic interface. We anticipate our methodology will translate in-silico screening of nucleic acid databases to a tangible enteroviral desktop detector, which could be readily translated to related organisms. This will pave-the-way forward in the clinical evaluation of disease and complement existing strategies at overcoming antimicrobial resistance.</p>

2019 ◽  
Author(s):  
Veeren Chauhan ◽  
Mohamed M Elsutohy ◽  
C Patrick McClure ◽  
Will Irving ◽  
Neil Roddis ◽  
...  

<p>Enteroviruses are a ubiquitous mammalian pathogen that can produce mild to life-threatening disease. Bearing this in mind, we have developed a rapid, accurate and economical point-of-care biosensor that can detect a nucleic acid sequences conserved amongst 96% of all known enteroviruses. The biosensor harnesses the physicochemical properties of gold nanoparticles and aptamers to provide colourimetric, spectroscopic and lateral flow-based identification of an exclusive enteroviral RNA sequence (23 bases), which was identified through in silico screening. Aptamers were designed to demonstrate specific complementarity towards the target enteroviral RNA to produce aggregated gold-aptamer nanoconstructs. Conserved target enteroviral nucleic acid sequence (≥ 1x10<sup>-7</sup> M, ≥1.4×10<sup>-14</sup> g/mL), initiates gold-aptamer-nanoconstructs disaggregation and a signal transduction mechanism, producing a colourimetric and spectroscopic blueshift (544 nm (purple) > 524 nm (red)). Furthermore, lateral-flow-assays that utilise gold-aptamer-nanoconstructs were unaffected by contaminating human genomic DNA, demonstrated rapid detection of conserved target enteroviral nucleic acid sequence (< 60 s) and could be interpreted with a bespoke software and hardware electronic interface. We anticipate our methodology will translate in-silico screening of nucleic acid databases to a tangible enteroviral desktop detector, which could be readily translated to related organisms. This will pave-the-way forward in the clinical evaluation of disease and complement existing strategies at overcoming antimicrobial resistance.</p>


Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 238
Author(s):  
Veeren M. Chauhan ◽  
Mohamed M. Elsutohy ◽  
C. Patrick McClure ◽  
William L. Irving ◽  
Neil Roddis ◽  
...  

Enteroviruses are ubiquitous mammalian pathogens that can produce mild to life-threatening disease. We developed a multimodal, rapid, accurate and economical point-of-care biosensor that can detect nucleic acid sequences conserved amongst 96% of all known enteroviruses. The biosensor harnesses the physicochemical properties of gold nanoparticles and oligonucleotides to provide colourimetric, spectroscopic and lateral flow-based identification of an exclusive enteroviral nucleic acid sequence (23 bases), which was identified through in silico screening. Oligonucleotides were designed to demonstrate specific complementarity towards the target enteroviral nucleic acid to produce aggregated gold–oligonucleotide nanoconstructs. The conserved target enteroviral nucleic acid sequence (≥1 × 10−7 M, ≥1.4 × 10−14 g/mL) initiates gold–oligonucleotide nanoconstruct disaggregation and a signal transduction mechanism, producing a colourimetric and spectroscopic blueshift (544 nm (purple) > 524 nm (red)). Furthermore, lateral-flow assays that utilise gold–oligonucleotide nanoconstructs were unaffected by contaminating human genomic DNA, demonstrated rapid detection of conserved target enteroviral nucleic acid sequence (<60 s), and could be interpreted with a bespoke software and hardware electronic interface. We anticipate that our methodology will translate in silico screening of nucleic acid databases to a tangible enteroviral desktop detector, which could be readily translated to related organisms. This will pave the way forward in the clinical evaluation of disease and complement existing strategies to overcome antimicrobial resistance.


Author(s):  
Thilo Schub ◽  
Johannes Forster ◽  
Sebastian Suerbaum ◽  
Johannes Wagener ◽  
Karl Dichtl

AbstractInfections by the basidiomycete yeast Cryptococcus neoformans are life-threatening diseases claiming more than 600,000 lives every year. The most common manifestation is cryptococcal meningitis in AIDS patients. Diagnosis primarily relies on antigen testing from serum and cerebrospinal fluid (CSF). Current guidelines recommend rapid antigen testing with a focus on point-of-care assays. Over the recent years, a range of new lateral flow assays (LFAs) was launched. There is still a lack of data evaluating the CE-certified Biosynex RDT CryptoPS LFA. We compared the performance of this LFA with a latex agglutination assay (LAA; Latex-Cryptococcus Antigen Detection System, IMMY) from blood and CSF samples. Blood and/or CSF samples of 27 patients with proven cryptococcal infections caused by different species and blood–CSF pairs of 20 controls were tested applying LFA and LAA. Upon combined analysis of blood and CSF, both assays were able to identify all C. neoformans infections. Based on CSF analysis only, the LFA and the LAA had sensitivities of 100% and 93%. Neither test gave false-positive results nor was reactive in two cases of C. non-neoformans/non-gattii species infections. Both assays have high sensitivities and specificities for the diagnosis of C. neoformans infection. Contrarily to the IMMY LAA, the RDT CryptoPS LFA is suitable as a point-of-care test but is limited in the quantification of antigen reactivity.


2001 ◽  
Vol 47 (10) ◽  
pp. 1885-1893 ◽  
Author(s):  
Paul Corstjens ◽  
Michel Zuiderwijk ◽  
Antoinette Brink ◽  
Shang Li ◽  
Hans Feindt ◽  
...  

Abstract Background: A lateral-flow (LF) device using the new reporter up-converting phosphor technology (UPTTM) was applied to DNA (hybridization) assays for the detection of specific nucleic acid sequences, thereby aiming to perform the test outside well-equipped laboratories. The methodology reported here is sensitive and provides a rapid alternative for more elaborate gel electrophoresis and Southern blotting. In a preliminary study, it was applied to screen for the presence of human papillomavirus type 16 (HPV16) in a defined series of cervical carcinomas. Methods: A LF assay was used to capture haptenized DNA molecules and hybrids, which were immunolabeled (before LF) with 400-nm UPT particles. These particles emit visible light after excitation with infrared in a process called up-conversion. Because up-conversion occurs in only the phosphor lattice, autofluorescence of other assay components is virtually nonexistent. Results: The use of the UPT reporter in LF-DNA tests, as compared with colloidal gold, improved the detection limit at least 100-fold. UPT LF-DNA tests were successfully applied to detect (in a blind test) the presence of HPV16 in DNA extracts obtained from cervical carcinomas. Test results matched 100% with previous characterization of these carcinomas. Conclusions: The use of UPT in LF assays to detect specific nucleic acids provides low attamole-range sensitivity. Hybridization and consecutive detection of PCR-amplified HPV16 sequences were successful in a background of 10 μg of fish-sperm DNA. The sensitivity of UPT detection in these complex mixtures indicates that detection of viral infections without PCR or other amplification technique is achievable.


Theranostics ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 5174-5196
Author(s):  
Tao Wang ◽  
Lanmei Chen ◽  
Arpitha Chikkanna ◽  
Suxiang Chen ◽  
Isabell Brusius ◽  
...  

Author(s):  
Bichismita Sahu ◽  
Santosh Kumar Behera ◽  
Rudradip Das ◽  
Tanay Dalvi ◽  
Arnab Chowdhury ◽  
...  

Introduction: The outburst of the novel coronavirus COVID-19, at the end of December 2019 has turned itself into a pandemic taking a heavy toll on human lives. The causal agent being SARS-CoV-2, a member of the long-known Coronaviridae family, is a positive sense single-stranded enveloped virus and quite closely related to SARS-CoV. It has become the need of the hour to understand the pathophysiology of this disease, so that drugs, vaccines, treatment regimens and plausible therapeutic agents can be produced. Methods: In this regard, recent studies uncovered the fact that the viral genome of SARS-CoV-2 encodes nonstructural proteins like RNA dependent RNA polymerase (RdRp) which is an important tool for its transcription and replication process. A large number of nucleic acid based anti-viral drugs are being repurposed for treating COVID-19 targeting RdRp. Few of them are in the advanced stage of clinical trials including Remdesivir. While performing close investigation of the large set of nucleic acid based drugs, we were surprised to find that the synthetic nucleic acid backbone is explored very little or rare. Results: We have designed scaffolds derived from peptide nucleic acid (PNA) and subjected them for in-silico screening systematically. These designed molecules have demonstrated excellent binding towards RdRp. Compound 12 was found to possess similar binding affinity as Remdesivir with comparable pharmacokinetics. However, the in-silico toxicity prediction indicates compound 12 may be a superior molecule which can be explored further due to its excellent safety-profile with LD50 (12,000mg/kg) as opposed to Remdesivir (LD50 =1000mg/kg). Conclusion: Compound 12 falls in the safe category of class 6. Synthetic feasibility, equipotent binding and very low toxicity of this peptide nucleic acid derived compounds can serve as a leading scaffold to design, synthesize and evaluate many of similar compounds for the treatment of COVID-19.


Author(s):  
Antonia Perju ◽  
Nongnoot Wongkaew

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.


2015 ◽  
Vol 51 (44) ◽  
pp. 9101-9104 ◽  
Author(s):  
B. Safeenaz Alladin-Mustan ◽  
Catherine J. Mitran ◽  
Julianne M. Gibbs-Davis

The ability to amplify nucleic acid sequences at room temperature without the need for any heating element has been achieved, which has promise in bio-diagnostics employed at the point of care.


2020 ◽  
Vol 38 (3) ◽  
pp. 199
Author(s):  
Narendra Yoga Hendarta ◽  
Abu Tholib Aman ◽  
Asmarani Kusumawati ◽  
Tri Wibawa

Lateral flow assay (LFD) based nucleic acid lateral flow (NALF)  method has been developed recently. The method met point of care testing (POCT) as simple and rapid procedures, less equipment, and can be performance by less skilled technician. NALF based on nucleic acid hybridizationis  more economical then immunochromatography assay which use antibody-antigen recognition. Cross hybridization has issued while used to differentiate organism with high GC content and high homology as high similarity genome. Some techniques has applied to give high stringency condition avoid cross hybridization reaction but need more procedure to apply. We found glycerol applied to buffer assay could reduce cross hybridization on nitrocellulose membrane. The study used 2 kinds of high stringency buffer as PBS and SSC bases and high concentration of ssDNA amplicon as sample. Without glycerol ingredient gave cross hybridization signal on test line. But used glycerol could reduce those even omitted with PBS based buffer assay. Beside those, glycerol could significantly increased hybridization signal in SSC based buffer assay (p<0.05).


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