Monitoring DNA Hybridization with Organic Electrochemical Transistors Functionalized with Polydopamine

Organic electrochemical transistors (OECTs) are finding widespread application in biosensing, thanks to their high sensitivity, broad dynamic range, and low limit of detection. An OECT biosensor requires the immobilization a biorecognition probe on gate, or else channel, through several, often lengthy, chemical steps. In this work, fast straightforward way functionalize carbon gate fully screen-printed by means polydopamine (PDA) film is presented. By an amine-terminated single-stranded oligonucleotide, containing HSP70 promoter CCAAT sequence, PDA film, detection complementary DNA strand demonstrated. Furthermore, specificity developed genosensor assessed comparing its response with one partially noncomplementary oligonucleotides. The sensor shows theoretical (LOD) 100 × 10−15 m range over four orders magnitude.