Bacterial nanocellulose (BNC) membranes are produced by some bacteria such as the specie Gluconacetobacter xylinus and commercially used as wound dressing. BC membranes have high crystalline 3D network composed by pure cellulosic fibers with diameters below 100 nm and lengths larger than 3 μm. BNC membranes have good adherence to the wound, enable excellent water vapor permeability, and constitute physical barriers for microorganisms.
In particular, BC membranes have been poorly explored as substrate for biosensensing materials based on sensors. Voltammetric sensors based on screen-printed carbon electrodes (SPCE's) built on BNC membranes may have an incredible potential to be used in biology–device interface. As a proof-of-concept, we evaluated the voltammetric behavior of well-known model analytes in SPCE's printed on BC membranes.
The SPCEs were home fabricated over dried BNC membranes substrate using a screen printer machine IMAH and appropriate stencil designs fabricated on polyester screens (150 meshes). First, a carbon layer was deposited on BC substrate using a pattern comprising the electrical contacts and the working and counter electrodes. They were obtained SPCEs with a working electrode area of 0.09 cm2 and films thickness (determined by profilometry measurements, n=9) of 8.7 µm for Ag/AgCl and 9.2 µm for carbon films.
By using BNC membrane as substrates for SPCE, we successfully detected uric acid, pyrogallic acid and ferrocyanide and ferricyanide ions model analytes dissolved in aqueous solutions at concentrations up to 60 ppm, 1 mM and 5 mM, respectively. We also evaluated the modification of SPCE working electrode with inkjet printed metallic nanoparticles and tyrosinase enzyme. Taking advantage of their remarkable biocompatibility, BNC membranes can be considered an excellent choice as an emergent biopolymer for the development of future implantable biosensors.
Nanoelectronic systems, components & devices , Nanosensors
