Ultrasensitive assay of 8-hydroxy-2′-deoxyguanosine in whole blood using carbon nanotubes based stochastic microsensors

8-hydroxy-2′-deoxyguanosine assay is having an important role in carcinogenesis, and accordingly is recognized as a discriminatory biomarker for early detection of breast cancer. Therefore, this article proposed two stochastic microsensors based on single (SWCNT) and multi (MWCNT) wall carbon nanotubes pastes, modified with α-cyclodextrin (α-CD) for the assay of 8-hydroxy-2′-deoxyguanosine in whole blood. The wider linear concentration range (1 × 10−12–1 × 10−6 mg L−1) was recorded when the microsensor based on SWCNT was used, while the highest sensitivity (7.38 × 107 s−1 g−1 mL) was recorded when the microsensor based on MWCNT was used. The type of carbon nanotube (SWCNT/MWCNT) was not influencing the limit of determination of 8-hydroxy-2′-deoxyguanosine (1 × 10−12 mg L−1). Very good correlations were obtained between the stochastic method and ELISA (the standard method), when used for the assay of 8-hydroxy-2′-deoxyguanosine in whole blood samples.