Interface interaction of MoS2 nanosheets with DNA based aptameric biosensor for carbohydrate antigen 15-3 detection

The combination of nanomaterials and DNA has captured extensive attention in the fields of sensor, catalysis, biomedicine and material science. The applications of DNA functionalized MoS2 nanosheets (NSs) in biosensor and biomedicine in turn present an fascinating topic about biointerface science between DNA and MoS2 NSs. The surface interaction between DNA and MoS2 NSs was explored by adsorption and desorption experiments. The results indicated that van der waals force played an crucial role in DNA adsorption by MoS2 NSs. Additionally, it was proved that the quenching of dye labelled DNA probe by MoS2 NSs was attributed to fluorescence resonance energy transfer. Based on the extraordinarily high quenching efficiency of MoS2 NSs and different adsorption affinity of MoS2 NSs toward aptamer and aptamer-targeted protein, an aptameric biosensor was fabricated to detect carbohydrate antigen 15-3. The fabricated biosensor not only displayed high sensitivity with the detection limit of 0.0039 U/mL (S/N = 3), but also exhibited good stability and selectivity. The proposed sensing platform provided an easy-constructed and cost-effective protocol to detect other aptamer targeted biomolecules. The fundamental study of biointerface science on DNA and MoS2 NSs will facilitate their potential applications in various fields.