Gradient nanoplasmonic imaging metasurface for rapid and label-free detection of SARS-CoV-2 sequences.

Compact and user-friendly nucleic acid biosensors play a crucial role in advancing infectious disease research, particularly for coronavirus (COVID-19). While nanophotonic metasurface sensors hold promise for high-performance sensing, they face challenges due to their complexity and bulky readout instruments. In this study, we propose a gradient nanoplasmonic imaging (GNI) metasurface that incorporates the concept of an optical potential well, enabling label-free single-step detection of SARS-CoV-2 sequences.

Highly selective recognition of the Al(ClO) molecule by a mono-pyrene substituted thiacalix[4]arene chemosensor.

A mono-pyrene substituted thiacalix[4]arene chemosensor (TCA-Py) was successfully synthesized in satisfactory yield. Fluorescence analysis revealed that TCA-Py exhibited a high recognition selectivity toward the Al(ClO) molecule due to the synergy between the Al cation and ClO anion. This unique ability to recognise an entire inorganic molecule broadens the field of molecular recognition.

5-Hydroxymethylcytosine and 5-formylcytosine containing deoxyoligonucleotides: facile syntheses and melting temperature studies.

An oxidation-based synthetic approach was developed for facile preparation of 5-formyl-2'-deoxycytidine and 5-hydroxymethyl-2'-deoxycytidine phosphoramidites. Upon introducing organic solvent components and copper catalysts, C5-methyl groups of 5-methyl-2'-deoxycytidine and thymidine were readily oxidized to formyl and hydroxyl functionality, respectively. Standard solid phase DNA synthesis and conventional deprotection methods were applicable to synthesize 5-formyl- or 5-hydroxymethyl-cytosine containing DNA oligonucleotides, which were used to study the effect of epigenetic modifications on DNA thermal dynamic stability.

Stimuli-responsive plasmonic core-satellite assemblies: i-motif DNA linker enabled intracellular pH sensing.

We report stimuli-responsive core-satellite assemblies of binary gold nanoparticles, linked by i-motif DNA, for live cell plasmonic imaging of pH changes in the endocytic pathway.

A Pt(II)-Dip complex stabilizes parallel c-myc G-quadruplex.

A new G-quadruplex (GQ) stabilizer, [Pt(Dip)2](PF6)2 (Dip: 4,7-diphenyl-1,10-phenanthroline), is prepared by the microwave irradiation method. The complex can highly stabilize G-quadruplex, but has negligible interactions with duplex DNA. Aromatic anchors on the polypyridyl ligands bestow the stabilizer with a high binding preference towards parallel GQ.