Fluorescence-Based Multimodal DNA Logic Gates.

The use of DNA structures in creating multimodal logic gates bears high potential for building molecular devices and computation systems. However, due to the complex designs or complicated working principles, the implementation of DNA logic gates within molecular devices and circuits is still quite limited. Here, we designed simple four-way DNA logic gates that can serve as multimodal platforms for simple to complex operations.

Single-Molecule FRET-Based Multiplexed Detection.

Single-molecule multiplexed detection is a high-promise toolkit for the expanding field of biosensing and molecular diagnostics. Among many single-molecule techniques available today for biomarker sensing including fluorescence, force, electrochemical, spectroscopic, barcoding, and other techniques, fluorescence-based approaches are arguably the most widely used methods due to their high sensitivity, selectivity, and readily available fluorophore-labeling schemes for a wide variety of biomolecules. However, multiplexed imaging using fluorescence techniques has proven to be challenging due to the sophisticated labeling schemes often requiring multiple FRET (fluorescence resonance energy transfer) pairs and/or excitation sources, which lead to overlapping signals and complicate data analysis.

Pulmonary haemorrhage as a frequent cause of death among patients with severe complicated Leptospirosis in Southern Sri Lanka.

Background: Leptospirosis is a tropical disease associated with life threatening complications. Identifying clinical and investigation-based parameters that predict mortality and morbidity is vital to provide optimal supportive care.

Methods: We conducted an observational study in an endemic setting, in the southern Sri Lanka.

Computational generation and characterization of IsdA-binding aptamers with single-molecule FRET analysis.

Staphylococcus aureus is a major foodborne bacterial pathogen. Early detection of S. aureus is crucial to prevent infections and ensure food quality.

FRET-Based Single-Molecule Detection of Pathogen Protein IsdA Using Computationally Selected Aptamers.

Iron-regulated surface determinant protein A (IsdA) is a key surface protein found in the foodborne bacteria─ ()─which is known to be critical for bacterial survival and colonization. is pathogenic and has been linked to foodborne diseases; thus, early detection is critical to prevent diseases caused by this bacterium. Despite IsdA being a specific marker for and several detection methods have been developed for sensitive detection of this bacteria such as cell culture, nucleic acids amplification, and other colorimetric and electrochemical methods, the detection of through IsdA is underdeveloped.

Single-Molecule Sensor for High-Confidence Detection of miRNA.

MicroRNAs (miRNAs) play a crucial role in regulating gene expression and have been linked to many diseases. Therefore, sensitive and accurate detection of disease-linked miRNAs is vital to the emerging revolution in early diagnosis of diseases. While the detection of miRNAs is a challenge due to their intrinsic properties such as small size, high sequence similarity among miRNAs and low abundance in biological fluids, the majority of miRNA-detection strategies involve either target/signal amplification or involve complex sensing designs.

Single-Molecule FRET-Based Dynamic DNA Sensor.

Selective and sensitive detection of nucleic acid biomarkers is of great significance in early-stage diagnosis and targeted therapy. Therefore, the development of diagnostic methods capable of detecting diseases at the molecular level in biological fluids is vital to the emerging revolution in the early diagnosis of diseases. However, the vast majority of the currently available ultrasensitive detection strategies involve either target/signal amplification or involve complex designs.

Single-Molecule Analysis of Nanocircle-Embedded I-Motifs under Crowding.

Cytosine (C)-rich regions of single-stranded DNA or RNA can fold into a tetraplex structure called i-motifs, which are typically stable under acidic pHs due to the need for protons to stabilize C-C interactions. While new studies have shown evidence for the formation of i-motifs at neutral and even physiological pH, it is not clear whether i-motifs can stably form in cells where DNA experiences topological constraint and crowding. Similarly, several studies have shown that a molecularly crowded environment promotes the formation of i-motifs at physiological pH; however, whether the intracellular crowding counteracts the topological destabilization of i-motifs is yet to be investigated.