Electrochemical sensor for quick and binder-free detection of vitamin B7 using shock waves treated hydroxyapatite/graphene oxide nanocomposite

Abstract

We report the fabrication of a novel electrochemical sensor for rapid and accurate determination of Vitamin B7 (biotin) using shockwaves treated hydroxyapatite/graphene oxide (SW-HAP/GO) composite modified glassy carbon electrode. Square wave voltammetry measurements at SW-HAP/GO modified GCE exhibits a strong peak at 1.45 V corresponding to the oxidation potential of biotin in phosphate buffer saline at pH 7.0. The results revealed a systematic increase in oxidation peak current with the increase in biotin concentration over a wide range of 16.7–611 µM and the lowest detection limit of 0.215 µM has been deduced. The practicability of the developed sensor has been demonstrated by determining biotin in vitamin B7 tablets, farm fresh groundnuts, dried groundnuts, almonds, pumpkin seeds, and egg yolk. The nuts and seeds samples (10 g each) were soaked in demineralised water for about 10 hours at room temperature and the extracts were used directly for SWV measurements. In all the cases, the SWV revealed a broad peak at about 1.4 V indicating the presence of biotin and from the calibration curves, the actual amount of B7 dissolved in water have been estimated as 1.46, 1.18, 0.43, 4.2, and 5.1 mcg in 10 g of farm fresh groundnuts, dried groundnuts, almonds, pumpkin seeds and egg yolk. Among the investigated samples, pumpkin seeds contain higher amount of biotin and it remained intact even after boiling in water. The fabricated SW-HAP/GO sensor offers potential for quick and precise determination of biotin in food and pharmaceutical industries without requiring streptavidin or antibody.