Size dependence of SiO2 particles enhanced glucose biosensor

A wide size range of SiO2 particles were synthesized and were used as enzyme immobilization carriers to fabricate glucose biosensors. The size of the particles was in the range of 17–520 nm. These biosensors could be operated under physiological conditions (0.1 M phosphate buffer, pH 7.2). Particle size could affect the performance of SiO2 modified glucose biosensors drastically. The smaller particles had higher performance. The smallest SiO2 modified biosensor could work well in the glucose concentration range of 0.02–10 mM with a correlation coefficient of 0.9993. Its sensitivity was 2.08 μA/mM and the detection limit was 1.5 μM glucose.