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Aggregate (Hoboken, N.J.) ; 2022.
Article in English | EuropePMC | ID: covidwho-1824576


The ongoing outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) pandemic has posed significant challenges in early viral diagnosis. Hence, it is urgently desirable to develop a rapid, inexpensive, and sensitive method to aid point‐of‐care SARS‐CoV‐2 detection. In this work, we report a highly sequence‐specific biosensor based on nanocomposites with aggregation‐induced emission luminogens (AIEgen)‐labeled oligonucleotide probes on graphene oxide nanosheets (AIEgen@GO) for one step‐detection of SARS‐CoV‐2‐specific nucleic acid sequences (Orf1ab or N genes). A dual “turn‐on” mechanism based on AIEgen@GO was established for viral nucleic acids detection. Here, the first‐stage fluorescence recovery was due to dissociation of the AIEgen from GO surface in the presence of target viral nucleic acid, and the second‐stage enhancement of AIE‐based fluorescent signal was due to the formation of a nucleic acid duplex to restrict the intramolecular rotation of the AIEgen. Furthermore, the feasibility of our platform for diagnostic application was demonstrated by detecting SARS‐CoV‐2 virus plasmids containing both Orf1ab and N genes with rapid detection around 1 h and good sensitivity at pM level without amplification. Our platform shows great promise in assisting the initial rapid detection of the SARS‐CoV‐2 nucleic acid sequence before utilizing quantitative reverse transcription‐polymerase chain reaction for second confirmation. An AIEgen‐graphene oxide (GO) nanocomposite‐based assay is designed for rapid detection of SARS‐CoV‐2 nucleic acids. The sensing mechanism is based on two‐stage fluorescence signal recovery due to fluorescence resonance energy transfer (FRET) effect by detaching AIEgen from GO surface and restricted intramolecular rotation (RIR) effect by formation of nucleic acid duplexes.

Adv Sci (Weinh) ; 9(17): e2105904, 2022 06.
Article in English | MEDLINE | ID: covidwho-1782563


Infectious virus outbreaks pose a significant challenge to public healthcare systems. Early and accurate virus diagnosis is critical to prevent the spread of the virus, especially when no specific vaccine or effective medicine is available. In clinics, the most commonly used viral detection methods are molecular techniques that involve the measurement of nucleic acids or proteins biomarkers. However, most clinic-based methods require complex infrastructure and expensive equipment, which are not suitable for low-resource settings. Over the past years, smartphone-based point-of-care testing (POCT) has rapidly emerged as a potential alternative to laboratory-based clinical diagnosis. This review summarizes the latest development of virus detection. First, laboratory-based and POCT-based viral diagnostic techniques are compared, both of which rely on immunosensing and nucleic acid detection. Then, various smartphone-based POCT diagnostic techniques, including optical biosensors, electrochemical biosensors, and other types of biosensors are discussed. Moreover, this review covers the development of smartphone-based POCT diagnostics for various viruses including COVID-19, Ebola, influenza, Zika, HIV, et al. Finally, the prospects and challenges of smartphone-based POCT diagnostics are discussed. It is believed that this review will aid researchers better understand the current challenges and prospects for achieving the ultimate goal of containing disease-causing viruses worldwide.

COVID-19 , Zika Virus Infection , Zika Virus , COVID-19/diagnosis , Clinical Laboratory Techniques , Humans , Laboratories , Point-of-Care Testing , Smartphone , Zika Virus Infection/diagnosis
ACS Appl Mater Interfaces ; 12(50): 55614-55623, 2020 Dec 16.
Article in English | MEDLINE | ID: covidwho-1387129


Multiplexed detection of viral nucleic acids is important for rapid screening of viral infection. In this study, we present a molybdenum disulfide (MoS2) nanosheet-modified dendrimer droplet microarray (DMA) for rapid and sensitive detection of retroviral nucleic acids of human immunodeficiency virus-1 (HIV-1) and human immunodeficiency virus-2 (HIV-2) simultaneously. The DMA platform was fabricated by omniphobic-omniphilic patterning on a surface-grafted dendrimer substrate. Functionalized MoS2 nanosheets modified with fluorescent dye-labeled oligomer probes were prepatterned on positively charged amino-modified omniphilic spots to form a fluorescence resonance energy transfer (FRET) sensing microarray. With the formation of separated microdroplets of sample on the hydrophobic-hydrophilic micropattern, prepatterned oligomer probes specifically hybridized with the target HIV genes and detached from the MoS2 nanosheet surface due to weakening of the adsorption force, leading to fluorescence signal recovery. As a proof of concept, we used this microarray with a small sample size (<150 nL) for simultaneous detection of HIV-1 and HIV-2 nucleic acids with a limit of detection (LOD) of 50 pM. The multiplex detection capability was further demonstrated for simultaneous detection of five viral genes (HIV-1, HIV-2, ORFlab, and N genes of SARS-COV-2 and M gene of Influenza A). This work demonstrated the potential of this novel MoS2-DMA FRET sensing platform for high-throughput multiplexed viral nucleic acid screening.

Biosensing Techniques , COVID-19/diagnosis , HIV Infections/diagnosis , HIV/isolation & purification , COVID-19/genetics , COVID-19/virology , Disulfides/chemistry , Fluorescence , Fluorescence Resonance Energy Transfer , HIV/pathogenicity , HIV Infections/genetics , HIV Infections/virology , Humans , Molybdenum/chemistry , Nanostructures/chemistry , Nucleic Acids/genetics , Nucleic Acids/isolation & purification , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity