Exponential Signal Amplification in CRISPR‐Functionalized Graphene/Silicon Heterojunction Barristor for Ultrasensitive DNA Detection

ABSTRACT

Clustered regularly interspaced short palindromic repeats functionalized graphene field‐effect transistors (CRISPR‐GFETs) have shown outstanding performance in the detection of DNA sequences within intact genomic material. However, their sensitivity is limited by the zero‐bandgap nature of graphene and the relatively weak conductance modulation in response to surface potential changes. Here, we report a highly sensitive DNA sensor array on a 4‐inch silicon wafer based on a CRISPR‐functionalized graphene/silicon heterojunction (CRISPR‐G/Si) barristor. The graphene surface was functionalized through robust π–π stacking of K3‐pyrene to enable specific immobilization of E3‐fused dSpCas9 ribonucleoprotein (RNP) complex via K3‐E3 coiled‐coil interactions. This RNP‐integrated platform facilitates recognition of target double‐stranded DNA (dsDNA) sequences through programmable single‐guide RNA (sgRNA)‐guided binding. Target DNA induces n‐type doping in graphene, raising its Fermi‐level ( E _F ) and reducing the G/Si Schottky barrier height (SBH). Unlike conventional GFETs that rely on quadratic conductance changes via Fermi‐level (), G/Si junctions exhibit an exponential conductance change via SBH modulation (σ∝exp(− Φ _SB )), enabling intrinsic signal amplification. The CRISPR‐G/Si barristor demonstrates a wide dynamic range from 1 pM to 100 n