Publications

Flexible electrochemical sensors based on electroactive materials have emerged as powerful analytical tools for biomedical applications requiring bioanalytes detection. Within this context, 3D printing is a remarkable technology for developing electrochemical devices, due to no design constraints, waste minimization, and batch manufacturing with high reproducibility. However, the fabrication of 3D printed electrodes is still limited by the in-house fabrication of conductive filaments, which requires the mixture of the electroactive material with melted of thermoplastic polymer (e.g., polylactic acid, PLA). Herein, a simple approach is presented for preparing electrochemical dopamine (DA) biosensors. Specifically, the surface of 3D-printed PLA specimens, which exhibit an elastic modulus and a tensile strength of 3.7 +/- 0.3 GPa and 47 +/- 1 MPa, respectively, is activated applying a 0.5 m NaOH solution for 30 min and, subsequently, poly(3,4-ethylenedioxythiophene) is polymerized in situ using aqueous solvent. The detection of DA with the produced sensors has been demonstrated by cyclic voltammetry, differential pulse voltammetry, and chronoamperometry. In summary, the obtained results reflect that low-cost electrochemical sensors, which are widely used in medicine and biotechnology, can be rapidly fabricated using the proposed approach that, although based on additive manufacturing, does not require the preparation of conductive filaments.

JTD Keywords: 3d printers, Additive manufacturing, Amines, Batch manufacturing, Biomedical applications, Chronoamperometry, Conducting polymer, Conducting polymers, Conductive filaments, Conservation, Cyclic voltammetry, Differential pulse voltammetry, Electroactive material, Electrochemical biosensor, Electrochemical devices, Electrochemical sensors, Electrodes, Electron emission, Flexible electrode, High reproducibility, Medical applications, Neurophysiology, Poly-3 ,4-ethylenedioxythiophene, Polyesters, Polylactic aci, Sodium hydroxide, Tensile strength, Thermoplastic polymer

Here we describe a label-free electrochemical DNA sensor based on poly(3,4-ethylenedioxythiophene)-modified (PEDOT-modified) electrodes. An acetylene-terminated DNA probe, complementary to a specific "Hepatitis C" virus sequence, was immobilized onto azido-derivatized conducting PEDOT electrodes using "click" chemistry. DNA hybridization was then detected by differential pulse voltammetry, evaluating the changes in the electrochemical properties of the polymer produced by the recognition event. A limit of detection of 0.13. nM was achieved using this highly selective PEDOT-based genosensor, without the need for labeling techniques or microelectrode fabrication processes. These results are promising for the development of label-free and reagentless DNA hybridization sensors based on conducting polymeric substrates. Biosensors can be easily prepared using any DNA sequence containing an alkyne moiety. The data presented here reveal the potential of this DNA sensor for diagnostic applications in the screening of diseases, such as "Hepatitis C", and genetic mutations.

JTD Keywords: Azido-EDOT, Click chemistry, Differential pulse voltammetry, DNA biosensor, Electrochemistry, Hepatitis C virus