Electrochemical self-signal switch for determination of KRAS gene employing riboflavin 5’-adenosine diphosphate functionalized MoS2 nanosheets

An electrochemical self-signal switch was designed for direct sensing of KRAS gene associated with lung cancer based on riboflavin 5’-adenosine diphosphate (RADP) functionalized MoS 2 nanosheets obtained by simple ultrasonication approach. RADP displayed favorable dispersive capacity for acquiring highly dispersed MoS 2 nanosheets in aqueous medium. The obtained RADP/MoS 2 nanocomposite demonstrated outstanding electrochemical redox activity and was adopted as the platform for the self-signal sensing of DNA immobilization and hybridization. The self-signal decreased when the probe ssDNA was immobilized on the acquired RADP/MoS 2 nanocomposite by virtue of the noncovalent π–π interaction between the conjugated nanocomposite and nucleic acid bases. After the hybridization, the formed dsDNA could be released off the surface of the conjugated nanocomposite as a result of the base burying, accompanied with the regeneration of the self-redox signal. Electrochemical self-signal response increased with the target DNA concentration from 1.0 × 10 −18 to 1.0 × 10 −8 mol/L, and a detection limit of 2.7 × 10 −19 mol/L was evaluated. Simultaneously, the developed DNA determination interface manifested remarkable specificity and superior steadiness. The proposed detection scheme is worth to popularize and has the potentiality for the implementation of various morbigenous gene without complex label steps.