Amplified detection of SARS‐COV‐2 B.1.1.529 (Omicron) gene oligonucleotides based on exonuclease III‐aided MoS₂/AIE nanoprobes

Abstract

The coronavirus disease‐2019 pandemic reflects the underdevelopment of point‐of‐care diagnostic technology. Nuclei acid (NA) detection is the “gold standard” method for the early diagnosis of the B.1.1.529 (Omicron) variant of severe acute respiratory syndrome‐coronavirus disease‐2. Polymerase chain reaction is the main method for NA detection but requires considerable manpower and sample processing taking ≥ 3 h. To simplify the operation processes and reduce the detection time, exonuclease III (Exo III)‐aided MoS2/AIE nanoprobes were developed for rapid and sensitive detection of the oligonucleotides of Omicron. Molybdenum disulfide (MoS2) nanosheets with excellent optical absorbance and distinguishable affinity to single‐strand and duplex DNAs were applied as quenchers, and aggregation‐induced emission (AIE) molecules with high luminous efficiency were designed as donor in fluorescence resonance energy transfer‐based nanoprobes. Exo III with catalytic capability was used for signal amplification to increase the sensitivity of detection. The composite nanoprobes detected the mutated nucleocapsid (N)‐gene and spike (S)‐gene oligonucleotides of Omicron within 40 min with a limit of detection of 4.7 pM, and showed great potential for application in community medicine.