Double-Stranded DNA Matrix for Photosensitization Switching

Abstract

LOD) down to 1 aM, which is comparable with that of the standard quantitative polymerase chain reaction (PCR). To facilitate point-of-care testing, a simple and low-cost paper strip has been developed for distance-based detection of LAMP amplicons with a LOD of 100 aM for HBV DNA.

Recombinase Polymerase Amplification Coupled with a Photosensitization Colorimetric Assay for Fast Salmonella spp. Testing

“…Herein, we address the current challenge in RPA readout systems by introducing a photosensitization colorimetric assay (PCA) for the direct visualization of RPA amplicons. We have previously developed a colorimetric assay protocol for facile quantification of double-stranded DNA (dsDNA), − which is based on the photosensitization activity switching of SYBR Green I (SG) upon binding with dsDNA . We envision that the PCA is a suitable readout for RPA because large amounts of dsDNA amplicons can be produced by RPA .…”

“…We have previously developed a colorimetric assay protocol for facile quantification of double-stranded DNA (dsDNA), 22−26 which is based on the photosensitization activity switching of SYBR Green I (SG) upon binding with dsDNA. 27 We envision that the PCA is a suitable readout for RPA because large amounts of dsDNA amplicons can be produced by RPA. 24 Moreover, PCA works in a label-free manner and features low-cost and less instrument-dependent for signal readout.…”

Selective Heavy Atom Effect Forming Photosensitizing Hot Spots in Double-Stranded DNA Matrix

“…Molecular docking was performed according to previous work with Surflex-Dock available in the Sybyl-X 2.0 program (Tripos Inc., St Louis, USA). 25 Briefly, the dsDNA structure of PDB code 2RT8 was built in the biopolymer builder module, and all the hydrogen atoms were added to define the correct configuration and tautomeric states. The EtBr structure was designed in the Sybyl program and energy minimized to a reasonable three-dimensional (3D) conformation through the Tripos force field (algorithm of distancedependent dielectric and Powell energy minimization).…”

“…Besides, such tunable metal specificity by recognition of Hg 2+ by T-T mismatch (Ag + by C-C mismatch) is not applicable in either the typical external or internal HAE mode. Through a simple LED-assisted photochemical chromogenic reaction step (oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB)), − selective HAE-induced photosensitization was demonstrated here for facile and ultrasensitive colorimetric Hg 2+ /Ag + sensing. Interestingly, such catalytic colorimetric sensing exhibited a higher sensitivity over fluorescence detection, which is not easily achievable in most cases.…”

Analysis of the Isotopic Purity of D2O with the Characteristic NIR-II Phosphorescence of Singlet Oxygen from a Photostable Polythiophene Photosensitizer

“…On the basis of the criteria, we think polythiophene (PT) may be appropriate, partially because its large π-conjugated backbone and delocalized electronic structure may endow it with broad absorption (Figures A and S3). Besides, Wohlgenannt et al stated that PTs exhibited interesting chromic features, i.e., the conformational change of the conjugated backbone results in a great change of the absorption and the ratio between singlet and triplet excited states (Figure B). , Generally, a twisted structure is advantageous for the population of the excited triplet states. − Therefore, polythiophene with a twisted structure due to the steric hindrance of phenyl groups (PT10, with 10 carbon atoms on the side chain) was prepared for investigations (for details, see Section 3 in the SI).…”