An array configuration to increase the performance of a biosensor

This study aims to investigate whether an amperometric biosensor in an array configuration can increase its signal-to-noise ratio (SNR) so as to increase its performance, like sensitivity. Uric acid biosensor (UAB) was used as an example in this study. Both single UAB (UAB-1 × 1) and UAB array (UAB-1 × 2 and UAB-1 × 3) were fabricated with uricase immobilized on commercial graphite working electrodes. The UAB showed an excellent (r2 > 0.96) linear response range (0–0.8 mM) and moderate response time (∼20 s). Results showed that the sensitivity and SNR of UAB can be significantly increased by the use of an array configuration. It was found that the sensitivity and SNR of the UAB-1 × 3 is significantly higher (p < 0.05 in all cases) than that of the UAB-1 × 1 (sensitivity: 3.1-fold; SNR: 4.4-fold) and UAB-1 × 2 (sensitivity: 1.9-fold; SNR: 3.4-fold). Moreover, an excellent linear relationship (r2 = 0.96) was found between the sensitivity and SNR. Finally, the UAB showed good repeatability (maximal relative standard deviation = 4.9%) and long-term stability (retained 92% of its initial value of current response after storing 60 days). In conclusion, the use of an array configuration can result in the increase of SNR, subsequently resulting in the increase of sensitivity.