DNA Aptamers on Borophene Nanosheets as an Electrochemical System for Omicron Detection

The current epidemic, caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) virus, has caused widespread devastation, with millions of people killed and millions more suffering from a variety of adverse effects. Due to this, it is crucial to implement screening procedures, such as the creation of highly sensitive technologies for early and rapid diagnosis. The current work thus demonstrates the detection of the SARS-CoV-2 variant, Omicron, employing specific aptamers created in a four-way junction (4-WJ) immobilized on boron sheets, also known as borophene, coated on an indium tin oxide surface. Borophene, a crystalline atomic monolayer of boron with a lattice spacing of 2.9 Å, is introduced as a transducer material for Omicron’s RNA electrochemical (EC) sensing. Its qualities are comparable to or even superior to those of graphene and Mxene when compared with electrochemical measurements, and it possessed a band gap of 3.5 eV. Further, as microRNAs are widely considered to be promising biomarker probes for sickness diagnoses, we designed a structure of 4-WJ aptamers on the surface of borophene nanocubes that allowed for the accurate identification of viral samples. The electrode material and sensor fabrication procedures were characterized by using analytical tools and EC measurements. The modified electrodes demonstrated higher electron transfer rates ( k 0 ) than their bare counterparts, with a k 0 value of 0.0049 cm s –1 and a charge transfer resistance ( R ct ) of 65 Ω. The biosensor performed well in the quantification of Omicron and can detect as low as 1.78 × 10 –16 M with a linear range from 0.1 to 1000 pg/mL. The sensor was also employed for clinical sample testing, which showed high reproducibility when done in parallel studies, and the selectivity and stability tests (>2 weeks) verified its usability in real-world situations.