Screen printed cupric-hexacyanoferrate modified carbon enzyme electrode for single-use glucose measurements

A highly selective disposable glucose biosensor based on the dispersion of cupric-hexacyanoferrate and glucose oxidase within a screen-printable carbon ink is described. The dispersed metal-hexacyanoferrate catalyst offers a marked decrease of the overvoltage for the reduction of the enzymatically-liberated hydrogen peroxide, and a stable response at physiological pH. Such efficient catalytic activity allows tuning of the detection potential to a region (around -0.1V) where interfering reactions are negligible. Such operation eliminates the need for an anti-interference membrane barrier, and along with the one-step dispersion of the enzyme and electrocatalyst, greatly simplifies the sensor fabrication. The high selectivity and simplified fabrication hold great promise for thick-film biosensors for testing glucose and other important substrates of other oxidases.