CRISPR/Cas13a-Based Nucleic Acid-Functionalized Discrete Floating-Gate Field-Effect Transistor for Amplification-Free Rapid Nipah Virus Detection

Abstract

Abstract Nipah virus (NiV) is a highly lethal zoonotic pathogen, and existing rapid diagnostic tools are scarce and reliant on nucleic acid amplification. In this study, we designed and fabricated a thin-film field-effect transistor with an IGZO channel and, for the first time, combined a discrete AuNP floating gate with the CRISPR/Cas13a system to achieve amplification-free detection of NiV. A pair of partially complementary nucleic acid reporter probes was used to attach AuNPs onto the channel, forming a nucleic acid-functionalized discrete floating gate. Under positive gate voltage, the AuNPs electrostatically induce mirror charges in the IGZO channel, amplifying the sensing signal. Additionally, the electrons can be injected from AuNPs into the channel via the Fowler–Nordheim tunneling effect under negative gate voltage, as a potential complementary sensing mechanism. The AuNPs are immobilized via nucleic acid strands, ensuring good biocompatibility. CrRNA was designed and the CRISPR system was optimized for compatibility with the FET, achieving amplification-free detection of NiV standards down to 10° copies/μL within 10 min. This study not only provides a reliable and rapid detection tool for NiV but also establishes a biosensing framework applicable to other pathogens.