Parylene-coated platinum nanowire electrodes for biomolecular sensing applications.

Nanoscale biosensors have gained attention in recent years due to their unique characteristics and size. Manufacturing steps, cost, and other shortcomings limit the widespread use and commercialization of nanoscale electrodes. In this work, a nano-size electrode fabricated by directed electrochemical nanowire assembly and parylene-C insulation is introduced. Results show that the diameter of the platinum nanowire and electrode tip length can be tuned down to 120 nm and 1.2 µm, respectively, where the exposed nanowires on the electrode tips are chemically active and their surfaces can be modified for specific biosensing applications. The biosensing testing with glucose and dopamine demonstrate limits of detection of 30 nM and 0.01 mM, respectively. The R-squared values for peak current versus concentration are 0.985 and 0.994, indicating strong linear correlations. These nanoscale electrodes hold great promise for single-cell biosensing applications due to their compact size, biocompatibility, and rapid fabrication.