Research Progress of Nucleic Acid Detection Technology Platforms for New Coronavirus SARS-CoV-2

Electrical Nanobiosensors for Nucleic Acid Based Diagnostics

Recent advances in nanotechnologies have promoted the iterative updating of nucleic acid sensors. Among various sensing technologies, the electrical nanobiosensor is regarded as one of the most promising prospects to achieve rapid, precise, and point-of-care nucleic acid based diagnostics. In this Perspective, we introduce recent progresses in electrical nanobiosensors for nucleic acid detection. First, the strategies for improving detection performance are summarized, including chemical amplification and electrical amplification. Then, the detection mechanism of electrical nanobiosensors, such as electrochemical biosensors, field-effect transistors, and photoelectric enhanced biosensors, is illustrated. At the same time, their applications in cancer screening, pathogen detection, gene sequencing, and genetic disease diagnosis are introduced. Finally, challenges and future prospects in clinical application are discussed.

New Imaging Modality of COVID-19 Pneumonia Developed on the Basis of Alzheimer’s Disease Research

Viral pneumonia caused by highly infectious SARS-CoV-2 poses a higher risk to older people and those who have underlying health conditions, including Alzheimer’s disease. In this work we present newly designed tacrine-based radioconjugates with physicochemical and biological properties that are crucial for the potential application as diagnostic radiopharmaceuticals. A set of ten tacrine derivatives was synthesized, labelled with gallium-68 and fully characterized in the context of their physicochemical properties. Based on these results, the final two most promising radioconjugates, [⁶⁸Ga]Ga-NODAGA-Bn-NH(CH₂)₉Tac and [⁶⁸Ga]Ga-THP-NH(CH₂)₉Tac, were selected for biodistribution studies. The latter compound was proven to be a good inhibitor of cholinesterases with significant affinity toward the lungs, according to the biodistribution studies. On the basis of molecular modelling combined with in vitro studies, we unraveled which structural properties of the developed tacrine derivatives are crucial for high affinity toward acetylcholinesterase, whose increased levels in lung tissues in the course of coronavirus disease indicate the onset of pneumonia. The radiopharmaceutical [⁶⁸Ga]Ga-THP-NH(CH₂)₉Tac was ultimately selected due to its increased accuracy and improved sensitivity in PET imaging of lung tissue with high levels of acetylcholinesterase, and it may become a novel potential diagnostic modality for the determination of lung perfusion, including in inflammation after COVID-19.

Establishment of a Rapid Typing Method for Coronavirus Disease 2019 Mutant Strains Based on PARMS Technology

Purpose: This study aims to establish a competitive allele-specific PCR based on penta-primer amplification refractory mutation system (PARMS) technology to detect the key mutation sites of variant of concern (VOC) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus for rapid typing. Methods: Competitive allele-specific primers and universal primers were designed for the key gene mutation sites N501Y, E484K, L452R, and K417N of SARS-CoV-2 VOCs, respectively.Using the principle of allele-specific polymerase chain reaction and fluorescence energy resonance transfer, different VOCs can be differentiated. Results: Using reverse transcribed cDNA of different VOCs as specimens, through double-blind detection, different VOC types can be effectively identified, with an accuracy rate of 100%. Through the identification and detection of different VOCs, effective differentiation can be achieved. Conclusions: The system has high specificity and sensitivity, with a detection limit of 1.28 copies/reaction.PARMS technology is fast, efficient, and low-cost. It is used for the identification and detection of the popular SARS-CoV-2 VOCs, which is helpful for the rapid and accurate prevention and control of COVID-19 epidemic.