CdS nanocrystals functionalized TiO2 nanotube arrays: Novel electrochemiluminescence platforms for ultrasensitive immunosensors

CdS nanocrystals (NCs) are decorated homogeneously on the TiO2 nanotube arrays (TiNT) by chemical bath deposition method. The resultant CdS/TiNT composite shows largely amplified electrochemiluminescence (ECL) signals due to the vertically aligned nanotubular structure. The ultrasensitive antigen detection is achieved on the composites via an efficient ECL quenching process introduced by sandwiched immunoreaction, and shows a detection limit of 1.0 fg mL− 1.

► The first ECL immunosensors based on semiconductor NCs modified TiO2 nanotube.
► The CdS/TiO2 nanotube arrays display amplified ECL signals than flat electrode.
► The resultant immunosensors show ultrasentsitive antigen detection.