ObjectivesCRISPR-Cas13a system-based nucleic acid detection methods are reported to have rapid and sensitive DNA detection. However, the screening strategy for crRNAs that enables CRISPR-Cas13a single-base resolution DNA detection of human pathogens remains unclear.MethodsA combined rational design and target mutation-anchoring CRISPR RNA (crRNA) screening strategy was proposed.ResultsA set of crRNAs was found to enable the CRISPR-Cas13 system to dramatically distinguish fluroquinolone resistance mutations in clinically isolated Mycobacterium tuberculosis strains from the highly homologous wild type, with a signal ratio ranging from 8.29 to 38.22 in different mutation sites. For the evaluation of clinical performance using genomic DNA from clinically isolated M. tuberculosis, the specificity and sensitivity were 100 and 91.4%, respectively, compared with culture-based phenotypic assays.ConclusionThese results demonstrated that the CRISPR-Cas13a system has potential for use in single nucleotide polymorphism (SNP) detection after tuning crRNAs. We believe this crRNA screening strategy will be used extensively for early drug resistance monitoring and guidance for clinical treatment.

In this paper, a tunnel field-effect transistor (TFET)-based voltage detector is proposed and its electrical characteristics are investigated using technology computer-aided design (TCAD) simulation. The operating principle of the proposed voltage detector is explained and possible applications in electrical overstress (EOS) and electrostatic discharge (ESD) protection are explored. Moreover, the impact of the key parameters on device performance is also discussed. The simulation results show that the proposed TFET-based voltage detector has a low leakage current and high detection sensitivity under EOS events compared to traditional diode-based detectors. With an additional nMOSFET capacitor, the proposed circuit can also be used for ESD protection. INDEX TERMS Band-to-band tunneling (BTBT); electrical overstress (EOS); electrostatic discharge (ESD); tunnel field-effect transistor (TFET); voltage detector.

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