Development of DNA biosensors for electrochemical detection of biomolecular interaction

In the first part of our study, miRNA-34a was detected by using impedimetric biosensor based on PAMAM dendrimer (G2-PS) modified screen printed electrode (G2-PS / SPE). The determination of the impedimetric miRNA-34a and the selectivity of the developed biosensor against different miRNAs were studied in buffer and fetal bovine serum (FBS) media. In the second part of our study, graphene oxide (GO) was modified at the surface of pencil graphite electrodes activated by covalent agents; impedimetric miRNA-34a detection was performed by using the prepared electrodes (GO-CA-PGE). The applicability of the developed electrodes for the determination of miRNA-34a in FBS and its selectivity against different miRNAs was tested. In the third part of our study, chitosan (CHIT) which is a biopolymer modified PGEs (CHIT-PGE) were developed and voltammetric detection of anticancer drug Daunorubicin (Dau) and DNA interaction was performed. The interaction mechanism was interpreted by monitoring the changes in Dau and guanine signals for the detection of Dau-fsDNA interaction on CHIT-PGE surface under optimum conditions. In the last part of our study, levan (LVN) modified PGEs (LVN-PGE) were developed and voltammetric detection of Dau and DNA interaction was performed. Both fsDNA and Dau analyzes and the detection of interaction was performed by using LVN-PGEs. The drug-DNA interaction was evaluated based on the changes at Dau and guanine signals.