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1.
ACS Applied Nano Materials ; 2022.
Article in English | Web of Science | ID: covidwho-2069854

ABSTRACT

The emergence of plasmonic nanostars with their attractive properties and unique versatility has enabled a wide range of advanced technologies critical to human health, safety, energy, and environmental remediation with vast potential for further exploration. In addition to their superior surface-to-volume ratios compared to those of other plasmonic nanostructures, plasmonic nanostars arguably possess the largest numbers of hotspots with intensely amplified electric fields when they are subjected to suitable electromagnetic waves to trigger localized surface plasmon resonance (LSPR). These outstanding characteristics make plasmonic nanostars ideal for many applications that benefit from the plasmonic enhancement effect of LSPR and/or the large surface area. Over the past decade, an increasing number of research endeavors has been reported on the synthesis and application of plasmonic nanostars to advance the state-of-the-art for various existing technologies. These contributions are pertinent to real-time image-guided multifunctional anticancer theranostics, the ultrasensitive on-site detection of the devastating virus SARS-CoV-2, multimodal multiplexed brain imaging, greatly enhanced catalysts for energy and environmental processes, or more efficient and stable solar cells. In addition to the enhancement of important but familiar technologies, plasmonic nanostars have also been employed to push the technological frontiers in multiple fields to enable applications such as maskless write-on lithography, nanosized field electron emitters, coherent random lasers, neural activity modulation, and optically controlled electrical currents. Despite great performance in various fields since their introduction, the nascency of this unique class of plasmonic nanostructures and the rise of unique types of plasmonic nanostars, in addition to the dominance of gold nanostars in recent years, indicate that there are still many opportunities for study, exploration, and development. This Review outlines a comprehensive picture of the current state of plasmonic nanostar research with a focus on their technological and scientific applications. We hope this Review will enlighten future collective endeavors to develop more effective plasmonic nanostars and incorporate them into mainstream technologies so that these stars can truly shine.

2.
Diagnostics (Basel) ; 12(10)2022 Oct 07.
Article in English | MEDLINE | ID: covidwho-2065755

ABSTRACT

This study evaluated the performances of immunoassays (LFIA and ELISA) designed for SARS-CoV-2 Antigen (Ag)-detection in nasopharyngeal (NP) and serum samples in comparison to RT-PCR. NP samples from patients with respiratory symptoms (183 RT-PCR-positive and 74 RT-PCR-negative samples) were collected from March to April and November to December 2020. Seroconversion and antigen dynamics were assessed by symptom onset and day of RT-PCR diagnosis. Serum samples from 87 COVID-19 patients were used to investigate the added value of Ag quantification, at diagnosis and during follow-up. The sensitivity of COVID-VIRO-LFIA on samples with Ct ≤ 33, considered as the contagious threshold, was 86% on NPs (CI 95%: 79-90.5) and 76% on serum samples (CI 95%: 59.4-88), with a specificity of 100%. Serum N-Ag was detected during active infection as early as day two from symptom onset, with a diagnostic sensitivity of 81.5%. Within one week of symptom onset, diagnostic sensitivity and specificity reached 90.9% (95% CI, 85.1%-94.6%) and 98.3% (95% CI, 91.1%-99.9%), respectively. Serum N-Ag concentration closely correlated with disease severity. Longitudinal analysis revealed the simultaneous increase of antibodies and decrease of N-Ag. Sensitivities of COVID-VIRO-LFIA and COV-QUANTO-ELISA tests on NP and serum samples were close to 80%. They are suitable COVID-19-laboratory diagnostic tests, particularly when blood samples are available, thus reducing the requirement for NP sampling, and subsequent PCR analysis. ELISA titers may help to identify patients at risk of poor outcomes.

3.
Biosensors (Basel) ; 12(10)2022 Sep 29.
Article in English | MEDLINE | ID: covidwho-2065702

ABSTRACT

The spread and resurgence of the SARS-CoV-2 virus (COVID-19 disease) threatens human health and social relations. Prevention of COVID-19 disease partly relies on fabricating low-cost, point-of-care (POC) sensing technology that can rapidly and selectively detect the SARS-CoV-2 virus. We report a colorimetric, paper-based polydiacetylene (PDA) biosensor, designed to detect SARS-CoV-2 spike protein in artificial saliva. Analytical characterizations of the PDA sensor using NMR and FT-IR spectroscopy showed the correct structural elucidation of PCDA-NHS conjugation. The PDA sensor platform containing the N-Hydroxysuccinimide ester of 10, 12-pentacosadiynoic acid (PCDA-NHS) was divided into three experimental PCDA-NHS concentration groups of 10%, 20%, and 30% to optimize the performance of the sensor. The optimal PCDA-NHS molar concentration was determined to be 10%. The PDA sensor works by a color change from blue to red as its colorimetric output when the immobilized antibody binds to the SARS-CoV-2 spike protein in saliva samples. Our results showed that the PDA sensing platform was able to rapidly and qualitatively detect the SARS-CoV-2 spike protein within the concentration range of 1 to 100 ng/mL after four hours of incubation. Further investigation of pH and temperature showed minimal influence on the PDA sensor for the detection of COVID-19 disease. After exposure to the SARS-CoV-2 spike protein, smartphone images of the PDA sensor were used to assess the sensor output by using the red chromatic shift (RCS) of the signal response. These results indicate the potential and practical use of this PDA sensor design for the rapid, colorimetric detection of COVID-19 disease in developing countries with limited access to medical testing.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , SARS-CoV-2 , COVID-19/diagnosis , Colorimetry/methods , Saliva, Artificial , Spectroscopy, Fourier Transform Infrared , Biosensing Techniques/methods , Esters , Saliva
4.
Microbiol Spectr ; 10(5): e0271422, 2022 Oct 26.
Article in English | MEDLINE | ID: covidwho-2053142

ABSTRACT

Monkeypox virus (MPXV) is a human pathogenic virus that belongs to the genus Orthopoxvirus. In 2022, MPXV caused an unprecedented number of infections in many countries. As it is difficult to distinguish MPXV from other pathogens by its symptoms in the early stage of infection, a rapid and reliable assay for MPXV detection is needed. In this study, we developed a loop-mediated isothermal amplification (LAMP) assay for the specific detection of MPXV and evaluated its application in simulated clinical samples. The A27L-1 and F3L-1 primer sets were identified as the optimal primers, and 63°C was the most appropriate reaction temperature for sequence amplification. The detection limits of the LAMP assay using primer sets A27L-1 and F3L-1 were both 20 copies/reaction mixture, which were >100-fold higher in terms of sensitivity, compared with conventional PCR. The LAMP assay findings were negative for all 21 non-MPXV pathogens, confirming the high specificity of our assay. All three types of simulated clinical samples were clearly identified by our LAMP assay, and the detection limits were consistent with the sensitivity results, indicating efficient clinical sample identification. Our rapid and reliable MPXV LAMP assay could be useful for MPXV detection and on-site diagnosis, especially in primary hospitals and rural areas. IMPORTANCE MPXV outbreaks rapidly grew in the first half of 2022, and this virus has been recognized as an increasing public health threat, particularly in the context of the COVID-19 pandemic. Thus, developing reliable and fast detection methods for MPXV is necessary.


Subject(s)
COVID-19 , Monkeypox , Humans , Monkeypox virus/genetics , Pandemics , Sensitivity and Specificity , Monkeypox/diagnosis , Monkeypox/epidemiology
5.
2022 12th International Workshop on Computer Science and Engineering, WCSE 2022 ; : 207-211, 2022.
Article in English | Scopus | ID: covidwho-2025939

ABSTRACT

COVID-19 is highly contagious and highly pathogenic, It seriously threatens human life and health. Rapid detection of positive COVID-19 cases is very important in stopping the spread of the virus. At early diagnosis, It is the most simple and rapid indicator for judging changes in the illness. As the COVID-19 chest X-ray image dataset continues to expand, Researchers build a CNN-based COVID-19 detection model on Apache Spark. The model can effectively detect positive cases of COVID-19. This article first introduces the big data platform Apache Spark, Deep Learning Technology CNN, transfer learning techniques, etc. Then, it summarizes the characteristics and deficiencies of the research on chest X-ray image recognition of COVID-19 in recent years. Finally, Under the big data thinking, This paper proposes a technical direction for rapid detection of COVID-19 based on the big data analysis platform Apache Spark and the deep learning algorithm CNN for large-scale COVID-19 chest X-ray image datasets. © 2022 WCSE. All Rights Reserved.

6.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 147-148, 2021.
Article in English | Scopus | ID: covidwho-2011699

ABSTRACT

Rapid polymerase chain reaction (PCR) utilizing plasmon-driven photothermal cycling requires real-time quantification of amplicons during PCR and miniaturization of real-time PCR (qPCR) system for point-of-care (POC) diagnostics. In this work, we have demonstrated handheld photothermal qPCR system with disposable aluminum PCR chips for the ultrafast amplification and real-time quantification of plasmids expressing SARSCoV-2 envelope protein within 5 min. This novel system provides stable and useful point-of-care diagnostic platform for prevention of fast-spreading pandemic in airport and harbor. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

7.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 835-836, 2021.
Article in English | Scopus | ID: covidwho-2011687

ABSTRACT

The COVID-19 outbreak spreads around world, accumulated to more than 27 million confirmed cases and 800k deaths. Polymerase Chain Reaction (PCR), a gold-standard diagnostic method, were labor intensive, time-consuming and costly, which restricted its application to widespread screening. Herein, this study purposes a one-pot and non-washing method to rapidly detect virus by dual-clamped surface-enhanced Raman scattering (SERS) mechanism. COVID Antigens were captured by SERS nanoparticles and novel SERS substrate simultaneously to achieve 6 order enhancements within 20 minutes. The dual-SERS sensors have reached a detection limit of 1 ng/ml in clinical samples for recognizing nucleocapsid & Spike proteins of COVID-19, which is comparable with PCR results. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

8.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 969-970, 2021.
Article in English | Scopus | ID: covidwho-2011590

ABSTRACT

Nucleic acid amplification detection is one of the most widely used molecular diagnostic techniques in recent years, which can rapidly and efficiently amplify the characteristic nucleotide sequences of pathogenic bacteria in the diagnosis of infectious diseases, it has been widely used in clinical diagnosis, disease screening and other fields. In this work, we report a micro-cavity digital PCR for rapid detection of pathogens on a silicon-based microfluidic chip. The device has the advantages of high flux, no pumping, rapid reaction, quantification and high sensitivity. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

9.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 859-860, 2021.
Article in English | Scopus | ID: covidwho-2011167

ABSTRACT

The global COVID-19 pandemic caused by the SARS-CoV-2 has claimed >3.5 million lives and resulted in detrimental social-economic impact. If reliable and rapid test systems were available at home or community level such as drive-by stations, the scope and impact of this tragedy could be largely reduced. Although the vaccine roll out has helped control the pandemic, it is important to develop rapid and accurate testing methods for detection of the SARS-CoV-2 which can be tuned to respond to its variants or similar corona viruses in response to potential outbreaks. In this work, we present a novel method for detection of the SARS-CoV-2 virus based on an antibody functionalized microwave sensor integrated with a microfluidic platform. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

10.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 85-86, 2021.
Article in English | Scopus | ID: covidwho-2012682

ABSTRACT

The COVID-19 pandemic spreads rapidly and globally. To quell the pandemic propagation, rapid and accurate detection of SARS-CoV-2 is urgently needed. Here, we present a nanopore coupled RT-LAMP method for SARSCoV-2 detection. After comparing all information from the nanopore experiment, we develop a method to use the event rate change of the amplicons translocation event to measure the amplification. As a result, our platform can distinguish positive from negative samples in 15 min with around 65 copies/reaction limit of detection and 100% specificity. We believe that the nanopore coupled RT-LAMP platform would provide a sensitive and specific detection for SARS-COV-2. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

11.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 1441-1442, 2021.
Article in English | Scopus | ID: covidwho-2012360

ABSTRACT

We report the development of an electrochemical sensor platform for ultrasensitive and rapid detection of SARS-CoV-2 viral RNA that integrates loop-mediated isothermal amplification (LAMP), CRISPR-based detection, and anti-fouling nanocomposite coating. By integrating LAMP amplification with CRISPR, we achieved ultrasensitive detection of SARS-CoV-2 RNA at levels as low as 5 copies µL-1. Data from this electrochemical diagnostic platform was comparable to traditional RT-PCR methodology in a fraction of the time, at low cost, and without requiring laboratory space. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

12.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 757-758, 2021.
Article in English | Scopus | ID: covidwho-2012303

ABSTRACT

The rapid and specific detection of nucleic acid sequences is highly demanded for several applications including pathogen diagnostics, quality control of biopharmaceutical products and forensics. Nucleic acid amplification methods based on mixtures of primers and polymerase enzymes such as polymerase chain reaction (PCR) and other isothermal methods are typically the standard approach. Here, using SARS-CoV-2 ORF1ab sequence as a model, we report the development of a simple enzyme-free and single-step competitive hybridization method allowing the specific detection of any type of nucleic acid sequence (ss/dsDNA or RNA) within 15 min with 89% sequence homology and sensitivity in the pM-range. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

13.
25th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2021 ; : 1445-1446, 2021.
Article in English | Scopus | ID: covidwho-2012281

ABSTRACT

A portable and low-cost electrochemical immunosensor platform is developed for rapid (13 min) and accurate quantification of SARS-CoV-2 serum antibodies (10.1 ng/mL − 60 µg/mL for IgG and 1.64 ng/mL − 50 µg/mL for IgM). No obvious cross-reactivity with other interference proteins was observed. Stable performance of the immunosensor within 24-week storage at room temperature was achieved. The practical use of the immunosensor was demonstrated using real patient samples. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

14.
CLEO: Science and Innovations, S and I 2022 ; 2022.
Article in English | Scopus | ID: covidwho-2012051

ABSTRACT

We demonstrated rapid detection of SARS-CoV-2 nucleocapsid protein antigen by dual-comb biosensing with surface modification of its corresponding antibody. A sensitivity close to that of RT-PCR was achieved, thanks to the use of active-dummy temperature compensation. © Optica Publishing Group 2022, © 2022 The Author(s)

15.
Anal Chim Acta ; 1226: 340286, 2022 Sep 15.
Article in English | MEDLINE | ID: covidwho-1995927

ABSTRACT

This study aims to use a paper-based sensor array for point-of-care detection of COVID-19 diseases. Various chemical compounds such as nanoparticles, organic dyes and metal ion complexes were employed as sensing elements in the array fabrication, capturing the metabolites of human serum samples. The viral infection caused the type and concentration of serum compositions to change, resulting in different color responses for the infected and control samples. For this purpose, 118 serum samples of COVID-19 patients and non-COVID controls both men and women with the age range of 14-88 years were collected. The serum samples were initially subjected to the sensor, followed by monitoring the variation in the color of sensing elements for 5 min using a scanner. By taking into consideration the statistical information, this method was capable of discriminating COVID-19 patients and control samples with 83.0% accuracy. The variation of age did not influence the colorimetric patterns. The desirable correlation was observed between the sensor responses and viral load values calculated by the PCR test, proposing a rapid and facile way to estimate the disease severity. Compared to other rapid detection methods, the developed assay is cost-effective and user-friendly, allowing for screening COVID-19 diseases reliably.


Subject(s)
COVID-19 , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/diagnosis , COVID-19 Testing , Colorimetry/methods , Electronic Nose , Female , Humans , Male , Middle Aged , Nucleic Acid Amplification Techniques , Point-of-Care Systems , Young Adult
16.
Southeast Asian Journal of Tropical Medicine and Public Health ; 53(3):345-355, 2022.
Article in English | Scopus | ID: covidwho-1981334

ABSTRACT

Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a robust and cost-effective assay for rapid diagnosis of SARS-CoV-2 compared to reverse transcription quantitative (RT-q) PCR. The study evaluated the performance of RT-LAMP technique that incorporated a simple Chelex 100 resin-based RNA extraction step for SARS-CoV-2 detection targeting virus E (encoding envelope protein) and RdRP (encoding RNA-dependent RNA polymerase). Using primer sets for E and RdRP, the developed RT-LAMP assay had a limit of detection (LOD) of 1 copy/µl transcribed RNA. For nasopharyngeal and oropharyngeal swab samples (n = 58), in comparison to the gold standard RT-qPCR (amplifying E and RdRP) sensitivity, specificity, positive predictive value, and negative predictive value of SARS-CoV-2 RT-LAMP assay targeting E gene was 88% (95% confidence interval (CI): 75-96%), 87% (95% CI: 59-98%), 99% (95% CI: 97-100%), and 28% (95% CI: 14-48%), respectively and for RdRP gene was 67% (95% CI: 51-98%), 87% (95% CI: 59-98%), 100% (95% CI: 96-100%), and 12% (95% CI: 8-18%), respectively. The whole process of RT-LAMP assay was completed within ~60 minutes. This developed RT-LAMP method for on-site COVID-19 detection should be useful in resource limited settings. © 2022, SEAMEO TROPMED Network. All rights reserved.

17.
Biology (Basel) ; 11(7)2022 Jul 06.
Article in English | MEDLINE | ID: covidwho-1963700

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) infection is an important acute diarrheal disease of swine that results in economic and industrial losses worldwide. The clinical manifestations in infected piglets are severe diarrhea, dehydration with milk curd indigestion, leading to death. The diagnosis of PEDV is essential for monitoring and managing the disease. PEDV can be detected and identified by serology and the nucleic acid of the virus in clinical samples. Therefore, a novel isothermal amplification and detection technique, reverse transcription-recombinase polymerase amplification couple nucleic acid lateral flow (RT-RPA-NALF) was developed for the rapid detection of PEDV. Qualitative reverse transcription-polymerase chain reaction (RT-qPCR) was established as the gold standard assay to compare results. Specific primer pairs and probes were designed, and RT-RPA conditions were optimized to amplify the M gene of PEDV. The established RT-RPA-NALF assay could finish in 25 min at a temperature of 42 °C and the amplicon interpreted by visual detection. The developed RT-RPA-NALF assay was specific to the M gene of PEDV, did not detect other common swine diarrhea pathogens, and showed minimal detection at 102 TCID50/mL PEDV. The RT-RPA-NALF assay can detect PEDV in 5 simulated fecal samples. Furthermore, in 60 clinical fecal samples, the results of RT-RPA-NALF correlated with RT-qPCR assay, which provides sensitivity of 95.65% and specificity of 100%, with a coincident rate of 98.33%. The rapid RT-RPA-NALF is simple and rapid, increases high sensitivity, and can be used in the field.

18.
IEEE Sensors Journal ; : 1-1, 2022.
Article in English | Scopus | ID: covidwho-1948818

ABSTRACT

Sensors with 60 nm gap junctions coated with aptamers that bind with S1 and S2 spiking proteins of the SARS-CoV-2 virus were developed. Sensor impedance changes with virus enabling rapid (~1 min), point-of-care detection. Exosomes and other nanoparticles in the saliva produce false positive signals but do not bind with aptamers and are easily removed to achieve 6% false positivity rates. A positive sensor voltage is used to attract negatively charged SARS-CoV-2 viruses to the junction and reduce sensor false negativity rates to below 7%. The limit of detection of the sensor is ~1000 viruses and can be altered by changing the sensor’s lateral dimensions and its transduction noise level. IEEE

19.
Biosensors (Basel) ; 12(7)2022 Jul 13.
Article in English | MEDLINE | ID: covidwho-1938693

ABSTRACT

The severe acute respiratory syndrome related coronavirus 2 (SARS-CoV-2) has spread globally and there is still a lack of rapid detection techniques for SARS-CoV-2 surveillance in indoor air. In this work, two test rigs were developed that enable continuous air monitoring for the detection of SARS-CoV-2 by sample collection and testing. The collected samples from simulated SARS-CoV-2 contaminated air were analyzed using an ultra-fast COVID-19 diagnostic sensor (UFC-19). The test rigs utilized two air sampling methods: cyclone-based collection and internal impaction. The former achieved a limit of detection (LoD) of 0.004 cp/L in the air (which translates to 0.5 cp/mL when tested in aqueous solution), lower than the latter with a limit of 0.029 cp/L in the air. The LoD of 0.5 cp/mL using the UFC-19 sensor in aqueous solution is significantly lower than the best-in-class assays (100 cp/mL) and FDA EUA RT-PCR test (6250 cp/mL). In addition, the developed test rig provides an ultra-fast method to detect airborne SARS-CoV-2. The required time to test 250 L air is less than 5 min. While most of the time is consumed by the air collection process, the sensing is completed in less than 2 s using the UFC-19 sensor. This method is much faster than both the rapid antigen (<20 min) and RT-PCR test (<90 min).


Subject(s)
Air Pollution, Indoor , COVID-19 , COVID-19/diagnosis , Humans , Limit of Detection , SARS-CoV-2 , Sensitivity and Specificity
20.
Biocell ; : 12, 2022.
Article in English | Web of Science | ID: covidwho-1897326

ABSTRACT

The SARS-CoV-2 outbreaks highlighted the need for effective, reliable, fast, easy-to-do and cheap diagnostics procedures. We pragmatically experienced that an early positive-case detection, inevitably coupled with a mass vaccination campaign, is a milestone to control the COVID-19 pandemic. Gold nanoparticles (AuNPs) can indeed play a crucial role in this context, as their physicochemical, optics and electronics properties are being extensively used in photothermal therapy (PTT), radiation therapy (RT), drug delivery and diagnostic. AuNPs can be synthesized by several approaches to obtain different sizes and shapes that can be easily functionalized with many kinds of molecules such as antibodies, proteins, probes, and lipids. In addition, AuNPs showed high biocompatibility making them useful tool in medicine field. We thus reviewed here the most relevant evidence on AuNPs as effective way to detect the presence of SARS-CoV-2 antigens. We trust future diagnostic efforts must take this 'old-fashioned' nanotechnology tool into consideration for the development and commercialization of reliable and feasible detection kits.

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