Fig. 1.

The schematic and characterizations of the graphene-CRISPR biosensors for the identification of SARS-CoV-2 variant Delta and SARS-CoV-2. (a) The workflow of the sample pretreatment for SARS-CoV-2 variant Delta. (b) The schematic of the graphene-CRISPR biosensor for the identification of SARS-CoV-2 Delta variant (denoted as Delta) by identifying L452R mutation site. (c) The fabrication of the biosensor. (d) The current of “signal-on” type biosensor recorded by the intercalation of [Ru(phen)₂dppz]BF₄ into the target DNA, producing a current peak at ∼0.5 V.