TalantaMar 21, 2026

Disposable laser-made graphene sensor strip for detecting N-protein using CRISPR and electrochemical measurement

CRISPR Gene Editing Weekly Brief ↗PubMed ↗DOI ↗

Updated Mar 25, 2026

Abstract

The developed ratiometric electrochemical biosensor achieves a linear response from 0.01 pM to 100 pM of SARS-CoV-2 N-protein with a detection limit of 1.3 × 10⁻¹⁰ pM.

The biosensor utilizes target-activated CRISPR-Cas12a activity for detecting the N-protein.
Methylene blue molecules provide an initial electrochemical signal by binding to guanine bases of a hairpin oligonucleotide.
CRISPR-Cas12a activation leads to the hybridization of a ferrocene-labeled indicator oligonucleotide, displacing methylene blue.
This displacement results in a measurable decrease in methylene blue current and an increase in ferrocene current.
The Fc/MB ratiometric signal correlates with increasing levels of the target N-protein.
Clinical feasibility for detecting N-protein was demonstrated using inactivated cell-cultured SARS-CoV-2.

Simplified

Pathogen detection is important for infectious diseases prevention and control. This study presents a novel positive-response, ratiometric electrochemical biosensor constructed on disposable laser-induced graphene (LIG) electrodes. The platform provides dual electrochemical signals for ultrasensitive detection of the SARS-CoV-2 N-protein by harnessing target-activated CRISPR-Cas12a trans-cleavage activity. The developed sensor incorporates a hairpin oligonucleotide (ON) functionalized on gold nanoparticles-deposited LIG electrode surface. Methylene blue (MB) molecules bind to guanine (G) bases of the hairpin ON through inherent affinity, generating the first electrochemical signal. Upon target-induced CRISPR-Cas12a activation, ferrocene (Fc)-labelled indicator ON hybridises with the hairpin ON, displacing the MB molecules and concurrently introduces the Fc as a secondary electrochemical signal reporter. Such displacement triggers a quantifiable decrease in MB electrochemical current and an increase in Fc electrochemical current, generating an Fc/MB ratiometric signal that enhances with increasing target levels and serves as the robust sensor response. The developed ratiometric biosensor achieves a linear response from 0.01 pM to 100 pM of N-protein with a detection limit of 1.3 × 10pM and with excellent selectivity. The clinical feasibility of the developed ratiometric electrochemical biosensor was confirmed by detecting N-protein in the inactivated cell-cultured SARS-CoV-2. This work demonstrates significant potential in rapid pathogen detection and point-of-care diagnostics. -3

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Competing interests

Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

PubMed

Disposable laser-made graphene sensor strip for detecting N-protein using CRISPR and electrochemical measurement

Abstract

Full Text

Funding

Competing interests

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