Fabrication of Cr doped SnO2 nanoparticles based biosensor for the selective determination of riboflavin in pharmaceuticals.

We report the fabrication and testing of a riboflavin (RF) biosensor based on the use of Cr doped SnO2 nanoparticles. The Cr-SnO2 nanoparticles with chromium concentration from 0 to 5 wt% were synthesised by a microwave irradiation method. Magnetic studies revealed that only 3 wt% Cr doped nano-SnO2 has ferromagnetic behaviour at room temperature. This Cr-SnO2 nanoparticles modified electrode responded to RF linearly over a concentration range of 0.2 × 10(-6) to 1.0 × 10(-4) M with a detection limit of 107 nM. The fabricated sensor showed an excellent anti-interference ability against electroactive species and metal ions and proved to be useful for the estimation of the RF content in pharmaceutical samples with satisfactory recovery.