CRISPR-Powered Transistors for DNA Biosensing

In recent years, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) has garnered a lot of attention for its potential for curative therapies. However, despite its sequence specific targeting capabilities, CRISPR-based biosensors have yet to be developed. We have recently developed a CRISPR powered, electronic biosensor termed, CRISPR-Chip, capable of detecting the binding interactions between nuclease deactivated CRISPR with its target sequence. CRISPR-Chip is a graphene field effect transistor (gFET) where the surface of the graphene is functionalized with nuclease deactivated CRISPR RNA-guided ribonucleoproteins (dRNPs). dRNPs within the CRISPR-Chip construct interact with their target sequence by scanning the whole genomic sample until they find and bind to their target sequence. The selective hybridization of the target DNA to the dRNP complex modulates the graphene’s conductivity and results in a detectable change in the gFET electrical signal output. CRISPR-Chip was able to detect dRNP binding to two commonly deleted exon target sequences within the human dystrophin gene, without amplification, obtained from clinical samples from patients with confirmed Duchene Muscular dystrophy disease. In addition, preliminary studies have also indicated the potential utilization of CRISPR-Chip for detection of single nucleotide polymorphisms (SNPs) at the target site. CRISPR-chip is the first example of CRISPR-powered electronic transistors that harness the search function of CRISPR/Cas9 and the ultrasensitivity of graphene-based nanoelectronics to enable a complete label-free and amplification-free DNA biosensor.