This seminar will cover the recent advances in the design and fabrication of folding- and dynamics-based electrochemical biosensors. These devices, which are often termed electrochemical DNA (E-DNA), aptamer-based (E-AB), and peptide-based (E-PB) sensors, are fabricated via direct immobilization of a thiolated and methylene blue (MB)-modified oligonucleotide or peptide probe onto a gold electrode. Binding of an analyte to the probe changes its structure and/or flexibility, which, in turn, influences the electron transfer between the MB label and the interrogating electrode. These sensors are resistant to false positive signals arising from the non-specific adsorption of contaminants and perform well even when employed directly in whole blood, saliva, and other realistically complex sample matrices. Furthermore, because all of the sensing components are chemisorbed onto the electrode surface, they are readily regenerable and reusable. Our results show that many of these sensors have achieved state-of-the-art sensitivity while offering the unprecedented selectivity, reusability and operational convenience of direct electrochemical detection.