A rapid and label-free DNA-based interference reduction nucleic acid amplification strategy for viral RNA detection

Interference Reduction Biosensing Strategy for Highly Sensitive microRNA Detection

“…The iridium­(III) complex 1 is a highly selective G-quadruplex probe with long-lived luminescence as reported in our previous work . To demonstrate the advantages of NEM-IR-RCA used in this study, we employed the fluorescent dye Coumarin460 (Cou460) as a representative interferent.…”

“…61−65 Previous studies have demonstrated that certain iridium(III) metal complexes can selectively recognize G-quadruplex and raise a luminescent enhancement response probably via the suppression of nonradiative delay of excited state and enhancement of triplet metal-to-ligand charge transfer ( 3 MLCT) emission of metal complexes. 56 In this study, to transduce the miRNA-21 detection into a visible output, the complementary sequence of the PS2.M, an 18-nucleotide DNA oligomer that was previously reported to bind hemin, 48,66,67 was incorporated into the padlock probe sequence (the orange part). After the ssDNA is cleaved by Nb.BbvCI, multiple G-quadruplexforming sequences would be released.…”

“…Importantly, the iridium(III) complexes are highly specific for The iridium(III) complex 1 is a highly selective Gquadruplex probe with long-lived luminescence as reported in our previous work. 56 To demonstrate the advantages of NEM-IR-RCA used in this study, we employed the fluorescent dye Coumarin460 (Cou460) as a representative interferent. Cou460 displays short-lived fluorescence, which interferes with the emission of complex 1 under steady-state emission mode.…”

“…The E-RCA reaction provides a three-dimensional (3D) G-quadruplex structure as a product, which is recognized by the iridium­(III) complexes with a strong luminescence response . The use of iridium­(III) complexes as probes provides the advantages of a strong luminescence signal and label-free and relatively low-cost operation. − Moreover, the long luminescence lifetime of iridium­(III) complexes can be exploited by TRES to decrease the background signal and thus improve the signal-to-background ratio. − Consequently, we established a sensitive method for miRNA detection combined with the luminescence signal amplification response and TRES technique. This strategy presented a limit of detection of miRNA-21 down to 0.0095 fM, which is comparable with the conventional RT-qPCR.…”

Advances in virus detection methods for wastewater-based epidemiological applications

“…The rolling circle amplification (RCA) technology has been used in the development of paper-based and electrochemical biosensors for SARS-CoV-2 RNA detection from clinical samples [ 42 , 43 ]. Chen et al (2022) integrated the mBRCA with time-resolved emission spectroscopy (TRES) to detect SARS-CoV-2 sequences (RdRp, ORF1ab and N) in spiked domestic sewage samples [ 24 ]. The observed LODs of the method used in the latter study for SARS-CoV-2 detection in sewage samples were in a range of 75 copies/μL to 88 copies/μL, which values are higher than the reported LODs of RT-LAMP based assays.…”