Dopamine modified hyperbranched TiO₂ arrays based ultrasensitive photoelectrochemical immunosensor for detecting...

In this work, three-dimensional (3D) hyperbranched TiO₂ nanorod arrays were synthesized and used to fabricate dopamine sensitized photoelectrochemical (PEC) biosensor. To increase the lifetime of charge carriers and enhance the photocurrent responses signal, a delicate signal amplification strategy by introducing dopamine (DA) as sensitizer was developed. The dopamine sensitized TiO₂ can shorten the carrier diffusion distance, improve light harvesting efficiency and charge collection efficiency, which results in performance improvement of the as-obtained PEC sensor. This proposed biosensor for determination of neuron specific enolase (NSE) demonstrated a good linear relationship range from 0.1 ng mL^-1 to 1000 ng mL^-1 with a detection limit of 0.05 ngmL^-1 (S/N = 3). In addition, the as-prepared immunosensor exhibits excellent selectivity, stability and reproducibility, which could be extended to other label-free sensing fields. Therefore, this proposed method may also provide potential applications for the clinical examination.