COVID-19, caused by SARS-CoV-2, was characterized by the WHO as pandemic in March 2020. The WHO determined that developing reliable tests for SARS-CoV-2 is essential to slow its fast-growing spread. Most current tests use PCR-based methods, which detect specific viral RNA sequences in samples from actively infected persons. However, PCR testing requires expensive instrumentation, qualified staff, is labor intensive, has several stages at which errors may occur between sampling and analysis, and frequent false negatives significantly complicate public health management. This poses significant risks for mankind and emphasizes the need for more reliable and cost-effective testing methods with increased accuracy and detection/turnaround time. Driven by this quest, an alternative method using viral antigen testing has recently been developed to rapidly detect active infections but has been found to be less sensitive than PCR tests. Our overarching hypothesis is that fluorescent biosensing technology, which offers high sensitivity, rapid response time, and simple instrumentation, is a viable and cost-effective alternative approach to detect active infections. In this presentation we discuss the development of an advanced fluorescence-based testing platform that exploits porous metal-organic frameworks (MOFs) to detect SARS-CoV-2 RNA. MOFs have emerged as a new class of porous materials composed of metal clusters or ions connected by polytypic organic linkers that form three-dimensional crystalline networks. Their resulting topologies, pore environments, and functionalities are controllable by both the choice of metal and organic building blocks. Key features—large accessible voids and high internal surface areas—render MOFs as ideal candidates to accommodate DNA probes (i.e., P-DNA) complementary to an RNA target (e.g., viral RNA for SARS-CoV-2 detection). And of note, P-DNA is fluorophore-labeled for easy spectroscopic detection. As part of the detection process, P-DNA adsorption into the MOF triggers fluorescence quenching (signal off) of the fluorophore tag, while fluorescence regeneration (signal on) is observed when the P-DNA-functionalized MOF (i.e., P-DNA@MOF) reacts with complementary RNA targets to form stable P-DNA–target RNA hybrids. In summary, we show that the functionalization of MOFs with fluorescent viral RNA binding sites can be used as a new means for the rapid and cost-effective spectroscopic detection of SARS-CoV-2 with enhanced accuracy.

Metal-organic frameworks as a fluorescence sensing platform for SARS-CoV-2 RNA

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.