A Plasmonic DNAzyme Strategy for Point-of-Care Genetic Detection of Infectious Pathogens

Naked-Eye Detection of Grapevine Red-Blotch Viral Infection Using a Plasmonic CRISPR Cas12a Assay

Herein, we described a novel plasmonic CRISPR Cas12a assay for the visual, colorimetric detection of grapevine viral infections. Our assay generates rapid and specific colorimetric signals for nucleic acid amplicons by combining the unique target-induced incriminate single-stranded DNase activity of Cas12a with plasmon coupling of DNA functionalized gold nanoparticles. The practical applicability of our plasmonic assay was successfully demonstrated through the detection of emerging red-blotch viral infections in grapevine samples collected from commercial vineyards.

FaptaSyme: A Strategy for Converting a Monomer/Oligomer-Nonselective Aptameric Sensor into an Oligomer-Selective One

Aptameric sensors can bind molecular targets and produce output signals, a phenomenon that is used in bioassays. In some cases, it is important to distinguish between monomeric and oligomeric forms of a target. Here, we propose a strategy to convert a monomer/oligomer-nonselective sensor into an oligomer-selective sensor. We designed an aptazyme that produced a high fluorescent output in the presence of oligomeric α-synuclein (a molecular marker of Parkinson's disease) but not its monomeric form. The strategy is potentially useful in the design of point-of-care tests for the diagnosis of neurodegenerative diseases.

DNA Antenna Tile-Associated Deoxyribozyme Sensor with Improved Sensitivity

Some natural enzymes increase the rate of diffusion-limited reactions by facilitating substrate flow to their active sites. Inspired by this natural phenomenon, we developed a strategy for efficient substrate delivery to a deoxyribozyme (DZ) catalytic sensor. This resulted in a three- to fourfold increase in sensitivity and up to a ninefold improvement in the detection limit. The reported strategy can be used to enhance catalytic efficiency of diffusion-limited enzymes and to improve sensitivity of enzyme-based biosensors.

MNAzyme-catalyzed nucleic acid detection enhanced by a cationic copolymer

Multi-component nucleotide acid enzymes (MNAzymes) derived from RNase-mimic DNAzymes have potential as simple and accurate DNA detectors. To enhance the MNAzyme activity under multiple-turnover conditions, a cationic comb-type copolymer, PLL-g-Dex, that facilitates hybridization and strand exchange reactions of DNA was utilized. The copolymer increased the MNAzyme reaction rate by 200 times, allowing target DNA detection at picomolar concentrations at physiological temperature.

A promising road with challenges: where are gold nanoparticles in translational research?

Nanoenabled technology holds great potential for health issues and biological research. Among the numerous inorganic nanoparticles that are available today, gold nanoparticles are fully developed as therapeutic and diagnostic agents both in vitro and in vivo due to their physicochemical properties. Owing to this, substantial work has been conducted in terms of developing biosensors for noninvasive and targeted tumor diagnosis and treatment. Some studies have even expanded into clinical trials. This article focuses on the fundamentals and synthesis of gold nanoparticles, as well as the latest, most promising applications in cancer research, such as molecular diagnostics, immunosensors, surface-enhanced Raman spectroscopy and bioimaging. Challenges to their further translational development are also discussed.

Deoxyribozyme cascade for visual detection of bacterial RNA

In the blink of the eye: a cascade of two deoxyribozymes was designed for rapid visual detection of bacterial 16S rRNA. The detection limit is 12.5 ng by the naked eye, with the ability to differentiate between closely related pathogenic and nonpathogenic species.