Nucleic acids play a central role in all domains of life, either as genetic blueprints or as regulators of various biochemical pathways. The chemical makeup of ribonucleic acid (RNA) or deoxyribonucleic acid (DNA), generally represented by a sequence of four monomers, also provides precise instructions for folding and higher-order assembly of these biopolymers that, in turn, dictate biological functions. The sequence-based specific 3D structures of nucleic acids led to the development of the directed evolution of oligonucleotides, SELEX (systematic evolution of ligands by exponential enrichment), against a chosen target molecule. Among the variety of functions, selected oligonucleotides named aptamers also allow targeting of cell-specific receptors with antibody-like precision and can deliver functional RNAs without a transfection agent. The advancements in the field of customizable nucleic acid nanoparticles (NANPs) opened avenues for the design of nanoassemblies utilizing aptamers for triggering or blocking cell signaling pathways or using aptamer-receptor combinations to activate therapeutic functionalities. A recent selection of fluorescent aptamers enables real-time tracking of NANP formation and interactions. The aptamers are anticipated to contribute to the future development of technologies, enabling an efficient assembly of functional NANPs in mammalian cells or in vivo. These research topics are *

Synthetic molecular machines have been explored to manipulate matter at the molecular level.

Coronavirus disease 2019 (COVID‐19) has become pandemic since March 11, 2020. Thus, development and integration in clinics of fast and sensitive diagnostic tools are essential. The aim of the study is a development and evaluation of a one‐step quantitative reverse transcription‐polymerase chain reaction (RT‐qPCR) assay (COVID‐19 Amp) for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) detection with an armored positive control and internal controls constructed from synthetic MS2‐phage‐based RNA particles. The COVID‐19 Amp assay limit of detection was 10 3 copies/ml, the analytical specificity was 100%. A total of 109 biological samples were examined using COVID‐19 Amp and World Health Organization (WHO)‐based assay. Discordance in nine samples was observed (negative by the WHO‐based assay) and discordant samples were retested as positive according to the results obtained from the Vector‐PCRrv‐2019‐nCoV‐RG assay. The developed COVID‐19 Amp assay has high sensitivity and specificity, includes virus particles‐based controls, provides the direct definition of the SARS‐CoV‐2 RdRp gene partial sequence, and is suitable for any hospital and laboratory equipped for RT‐qPCR.

Rapid and cost‐efficient methods for diagnostics of infectious diseases can expedite prescription of adequate treatment, thus shortening the patients’ recovery and reducing adverse side effects. In this study, we developed a procedure for visual detection of bacterial pathogens Gram‐negative Neisseria meningitidis and Gram‐positive Streptococcus pneumoniae directly from human samples of cerebrospinal fluid (CSF). The assay uses hybridization probes that can efficiently recognize folded single‐stranded DNA analytes due to their split design. The assay includes the following stages: PCR amplification of N. meningitidis and S. pneumoniae targeted sequences; λ exonuclease treatment of the polymerase chain reaction (PCR) amplicons, and detection of the amplicons by hybridization probes with visual signal output. The assay requires 2.0 h with hands‐on time of about 40 min, and a regular PCR thermal cycler. It detects down to 10 bacteria in 2 μL of cerebrospinal fluid. The assay works for both gram‐positive and gram‐negative bacteria and does not require optimization of PCR conditions. This development creates a basis for the point‐of‐care diagnostics of bacterial meningitis with visual signal output.