Aptamer-based CRISPR-Cas powered diagnostics of diverse biomarkers and small molecule targets

Abstract

CRISPR-Cas systems have been widely used in genome editing and transcriptional regulation. Recently, CRISPR-Cas effectors are adopted for biosensor construction due to its adjustable properties, such as simplicity of design, easy operation, collateral cleavage activity, and high biocompatibility. Aptamers’ excellent sensitivity, specificity, in vitro synthesis, base-pairing, labeling, modification, and programmability has made them an attractive molecular recognition element for inclusion in CRISPR-Cas systems. Here, we review current advances in aptamer-based CRISPR-Cas sensors. We briefly discuss aptamers and the knowledge of Cas effector proteins, crRNA, reporter probes, analytes, and applications of target-specific aptamers. Next, we provide fabrication strategies, molecular binding, and detection using fluorescence, electrochemical, colorimetric, nanomaterials, Rayleigh, and Raman scattering. The application of CRISPR-Cas systems in aptamer-based sensing of a wide range of biomarkers (disease and pathogens) and toxic contaminants is growing. This review provides an update and offers novel insights into developing CRISPR-Cas-based sensors using ssDNA aptamers with high efficiency and specificity for point-of-care setting diagnostics.

Low-Background CRISPR/Cas12a Sensors for Versatile Live-Cell Biosensing

“…The recent discovery and development of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas), together known as the CRISPR/Cas system, has sparked a boom in the fields of genome editing and medical diagnosis. − Particularly, as a well-known member of the CRISPR/Cas family, CRISPR/Cas12a is a class 2 type V CRISPR-associated enzyme that binds to a single-stranded guide CRISPR RNA (crRNA). Compared with the other members of the CRISPR/Cas family, CRISPR/Cas12a has some unique characteristics. , It is able to cleave not only double-stranded DNA (dsDNA) with high sequence-specificity ( cis -cleavage activity) but also single-stranded DNA (ssDNA) in a sequence-independent manner ( trans -cleavage activity). ,− In view of the unique properties, numerous Cas12a-based biosensors have been developed for the detection of different targets. − Despite remarkable progress in recent years, − CRISPR/Cas12a-based biosensors still mainly target at nucleic acids and are rarely used in live cells. Scientists are curious about whether the CRISPR/Cas system can be deployed as a general live cell biosensing tool for a wide range of intracellular biomolecules and not just nucleic acid-associated targets.…”

Direct Electrochemistry of Glucose Dehydrogenase-Functionalized Polymers on a Modified Glassy Carbon Electrode and Its Molecular Recognition of Glucose

“…Electrochemical biosensors have been used in biological, medicinal, and industrial analysis because of its specificity, high efficiency, simplicity, and quickness. Particularly, like CRISPR-cas aptamer-based sensor [ 5 , 6 ], molecularly imprinted polymers (MIPs) technology and enzyme-based sensors [ 7 , 8 ] have attracted a lot of attention. CRISPR-cas aptamers are more stable than antibodies or proteins.…”

“…CRISPR-cas aptamers are more stable than antibodies or proteins. CRISPR-cas aptamer-based sensors can be stored at room temperature without losing functional activity [ 5 ]. Molecularly imprinted polymers (MIPs) first combine template molecules and functional monomers with covalent or noncovalent bonds through self-assembly.…”

Ethanol and NaCl-Induced Gold Nanoparticle Aggregation Toxicity toward DNA Investigated with a DNA/GCE Biosensor

“…In many areas, the use of gold nanoparticles is increasing. The presence of AuNPs in polymer composites plays a key role in food packaging [ 6 , 7 , 8 ]. AuNPs are used in wound healing [ 9 , 10 ], other diagnostic and therapeutic medical applications [ 11 , 12 , 13 ], and cosmetics [ 14 , 15 , 16 ].…”