Gold nanobipyramids integrated ultrasensitive optical and electrochemical biosensor for Aflatoxin B1 detection

This work reports the development of an electrical and optical biosensing for label-free detection Aflatoxin B1 (AFB1) using gold (Au) nanobipyramids (NBPs). AuNBPs were synthesized through a two-step seed-mediated growth process followed by exchange capping agent from surfactant to lipoic acid. Pure monodispersed 70 nm base length obtained deposited on indium tin oxide (ITO)-coated glass substrate modified with self-assembled (3-Aminopropyl) triethoxysilane (APTES) film. The characterization surfaces spectroscopy, microscopy diffractometry confirms formation AuNBPs, conjugation ITO electrode immobilization anti-AFB1 antibodies. substrates used both electrochemical Surface Plasmon Resonance studies. Localized (LSPR) local field enhancement was demonstrated. SPR based AFB1 found be linear in 0.1–500 nM range limit 0.4 nM, whereas, impedimetric shown 0.1–25 0.1 nM. practical utility sensor tested spiked maize samples 95–100% recovery percentage together low relative standard deviation, proof robustness this sensor.