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Fluorescence-based diagnostic tools are attractive and versatile tests with multiple advantages: ease of use, sensitivity and rapid results. The advent of CRISPR-Cas technology has created new avenues for the development of diagnostic testing tools. In this study, by effectively combining the specific functions of two enzymes, CRISPR-Cas12a and terminal deoxynucleotidyl transferase (TdT), we developed a DNA detection assay that generates copper nanoparticles (CuNPs) that are easily visible to the naked eye under UV-light; we named this detection assay Cas12a Activated Nuclease poly-T Reporter Illuminating Particles (CANTRIP). Upon specific target DNA recognition by Cas12a, single-stranded DNA (ssDNA) reporter oligos with blocked 3'-ends are cut into smaller ssDNA fragments, thereby generating neo 3'-hydroxyl moieties. TdT subsequently elongates these newly formed ssDNA fragments, incorporating only dTTP nucleotides, and these poly(thymine)-tails subsequently function as scaffolds for the formation of CuNPs. These CuNPs produce a bright fluorescent signal upon UV excitation, and thus, this bright orange signal indicates the presence of target DNA, which in this proof-of-concept study consisted of anthrax lethal factor plasmid DNA. CANTRIP, which combines two detection platforms consisting of CRISPR-Cas12a and fluorescent CuNPs into a single reaction, appears to be a robust, low-cost and simple diagnostic tool.
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http://dx.doi.org/10.1093/biomethods/bpaa020 | DOI Listing |
J Phys Chem Lett
September 2025
Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States.
Carbon dots (CDs) represent a new class of nontoxic and sustainable nanomaterials with increasing applications. Among them, bright and large Stokes-shift CDs are highly desirable for display and imaging, yet the emission mechanisms remain unclear. We obtained structural signatures for the recently engineered green and red CDs by ground-state femtosecond stimulated Raman spectroscopy (FSRS), then synthesized orange CDs with similar size but much higher nitrogen dopants than red CDs.
View Article and Find Full Text PDFAdv Mater
September 2025
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Helicene-based circularly polarized luminescence (CPL) materials suffer from severely low color purity in circularly polarized organic light-emitting diodes (CP-OLEDs). Here, a novel molecular engineering strategy is introduced by replacing helicene containing continuous fused benzene rings with a multiple resonance (MR) framework comprising discontinuous fused benzene rings. This approach effectively suppresses high-frequency C─C bond stretching vibrations and enhances short-range charge transfer, enabling high color purity, CPL activity, and efficient thermally activated delayed fluorescence (TADF).
View Article and Find Full Text PDFACS Synth Biol
September 2025
ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, Brisbane, QLD 4000, Australia.
Fluorescent proteins (FPs) are commonly used as reporters to examine intracellular genetic, molecular, and biochemical status. Flow cytometry is a powerful technique for accurate quantification of single-cell fluorescent levels. Here, we characterize green, red, and blue FPs for use in yeast .
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
Shaanxi Key Laboratory of New Concept Sensors and Molecular Materials, Key Laboratory of Applied Surface and Colloids Chemistry, Department of Chemistry and Chemical Engineering, ShaanXi Normal University, Xi'an, 710062, P.R. China.
Rhodamine derivatives exhibiting inverted open-closed form fluorescence behavior redefines conventional photochemical paradigms while illuminating new structure-property relationships and fascinating application potentials. Herein, we report a donor-acceptor engineering strategy that activates closed form emission in rhodamines, achieving unprecedented Stokes shifts (>280 nm) while overcoming aggregation-caused quenching. The new class of rhodamines with inverted open-close form emission behavior are created through simultaneous substitution of N,N-diethyl groups with indole (donor) and conversion of spiro-lactam to benzene sulfonamide (acceptor).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
Department of Optical Nanoscopy, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120, Heidelberg, Germany.
Controlled photoactivation is an auspicious and emerging approach in super-resolution microscopy, offering virtually zero background signal from the marker prior to activation. Pyronins are well-established fluorophores, but due to their inherent intercalating tendency towards nucleic acids, their use has been mostly avoided in super-resolution microscopy. Here, we describe a new class of diaryl ether and diaryl silane molecules that upon photoactivation close into fluorescent (silicon-)pyronins and term them Pyronin Upon Light Irradiation (PULI).
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