A novel self-powered DNA biosensor was successfully developed based on a dual chambered microbial fuel cell (MFC) apparatus as a power supply and ketamine (KET) as a hybridization indicator. A graphite electrode coated with gold nanoparticles (GNP/graphite electrode), which provided larger surface area for immobilization of thiolated single stranded (ssDNA) probe, was used as biocathode in the MFC system. When KET was used as the hybridization indicator for detection of ssDNA probe, the indicator exhibited excellent selectivity in detecting and discriminating the complementary, single base mismatched, and noncomplementary target sequences. Furthermore, this self-powered biosensor based on MFC apparatus served as the biosensing platform for determination of KET in clinical serum samples. Under the steady state operation condition, the difference between power densities of the ssDNA probe modified GNP/graphite cathode in the absence and presence of accumulated KET (∆P) served as the detection signal with a detection limit of 0.54 nM. The proposed MFC-based self-powered biosensor, as a low-cost portable device, showed a high sensitivity, stability, and reproducibility. Therefore, it can become a promising platform for determination of KET in clinical researches.
