A photoelectrochemical immunosensor for tris(2,3-dibromopropyl) isocyanurate detection with a multiple hybrid CdTe/Au–TiO2 nanotube arrays

Abstract

In this paper, tris(2,3-dibromopropyl) isocyanurate (TBC) is for the first time as far as we know determined by ultrasensitive photoelectrochemical (PEC) immunoassay using an antibody-modified ternary hybrid CdTe/Au–TiO₂ nanotube arrays (NTAs) photoelectrode, developed by the pulse electrodeposition technique. The as-prepared hybrid shows enhanced photon absorption and photocurrent response, which subsequently increased the photoelectrical conversion efficiency in the visible region. TBC-antibody (Ab) was developed in rabbits as a result of immunization with the BSA–TBC conjugate and covalently cross-linked onto the CdTe/Au–TiO₂ NTAs. Since the photocurrent is highly dependent on the TiO₂ surface properties, the specific interaction between TBC and the antibody results in a sensitive change in the photocurrent, which displayed a linear range of 5.0 × 10⁻¹¹ to 5.0 × 10⁻⁵ M and a low detection limit of 5.0 × 10⁻¹¹ M for TBC determination. This proposed strategy highlights the application of TiO₂ nanotube in visible-light-activated photoelectrochemical biosensing, which could largely reduce the destructive effect of UV light on biomolecules.