Single Printing Step Prussian Blue Bulk-Modified Transducers for Oxidase-Based Biosensors

We report on hydrogen peroxide sensors made through a single printing step with carbon ink containing catalytically synthesized Prussian blue nanoparticles. Despite their reduced sensitivity, the resulting bulk-modified sensors displayed both a wider linear calibration range (5 × 10^-7-1 × 10^-3 M) and an approximately four times lower detection limit versus the surface-modified sensors due to the dramatically decreased noise resulting in, on average, a six times higher signal-to-noise ratio. The corresponding glucose and lactate biosensors demonstrated similar and even higher sensitivities compared to those of biosensors based on surface-modified transducers. The biosensors have been validated through analysis of human serum. The decreased time and cost for production of single printing step bulk-modified transducers, as well as their analytical performance characteristics, which are advantageous over conventional surface-modified ones, would be expected to enable their wide use in (bio)sensorics.