Lead-start isothermal polymerase amplification controlled by DNAzymatic switches

Abstract

As DNA polymerases are even active at ambient temperature, there is inevitable non-specific amplification; to avoid the undesired amplification of analytes, heat activation-based polymerase chain reaction (PCR), called hot-start PCR,...

Smartphone-based point-of-care testing of the SARS-CoV-2: A systematic review

“… RNA virus + detection of the B.1.1.7, B.1.351, or P.1 variants threshold of ∼2000 relative fluorescence units (RFUs) for the detection of SARS-CoV-2 NR 1 hour NR The app uses the embedded camera in a smartphone in combination with a color segmentation algorithm [35] Fluorescence respiratory swab samples mineral oil was added to cover the extracted nucleic acids with amplification RNA virus 20 copies RNA of SARS-CoV-2 100% 40 min NR Enable detection of fluorescence by naked eyes [36] Fluorescence nasal swab and saliva diluting the swab in a nontoxic buffer, and mixing with reagents SARS-CoV-2 nucleocapsid phosphoprotein & SARS-CoV-2 RNA 0.38 SARS-CoV-2 RNA copies/μl 0.5 to 2.5 copies/μL 95% 17 min NR software to guide for setting up the test. [37] Fluorescence Serum and saliva samples Human serum or saliva was stained for 6 min with the SYBR Green dye SARS-CoV-2′s nucleocapsid gene (N-protein) 0.1 nM NR NR NR Imaging, Processing by application [38] Flourescence. Blood specimens interleukin-6 antibodies and thrombin binding aptamers 50 μg/ml for the IL-6 and 1 μM for the thrombin Not Reported NR Huawei P30 Pro smartphone using a 3Dprinted dark box.…”

“…Yoo et al. [38] aimed to design a diagnostic assay that would allow quantification of SARS-CoV-2 in serum or saliva samples. The study used "lead-start isothermal amplification," which allowed DNA polymerases to be activated or deactivated at room temperature on demand using lead ion (Pb 2+ ) activation.…”

Ionic liquid-caged nucleic acids enable active folding-based molecular recognition with hydrolysis resistance

“…For example, the ATP aptamer was chemically modified to induce target-specific close proximity between 5′ FAM and 3′ BHQ1 ( 72 ), and as a result, the presence of ATP, the nonfluorescent ligand, was specifically reported even in the CDHP in a concentration-dependent manner ( Supplementary Figure S16 ). All the observations reveal that with no risk of hydrolysis, a variety of FNAs could be systematically combined to create more complex, yet highly useful molecular functions, such as ligand-induced chemical reactions (2), chemically regulated molecular recognition ( 73 ), and stimuli-responsive structural assembly and disassembly ( 74 ).…”

De novo selected hACE2 mimics that integrate hotspot peptides with aptameric scaffolds for binding tolerance of SARS-CoV-2 variants

“…Similarly, the creation of biomarker-targeting peptide-aptamer hybrid ligands would also be highly valuable for targeted drug delivery and early diagnostics, allowing reproducible and scalable chemical synthesis and modification. Moreover, as different modalities can be readily included in the nucleic acid–based scaffold, the peptide-aptamer hybrid ligands could be programmed to perform elaborate actions, such as structure switching ( 48 , 49 ), catalytic reactions ( 50 ), target colocalization ( 51 ), for biosensing, cell signaling, and even synthetic biology applications.…”