A novel Prussian blue/PANI nanostructure-based biosensor for ultrasensitive determination of trace hydroquinone

A sensitive, accurate, and low-cost hydroquinone detection method is always desired due to the great threat of hydroquinone to human beings and environment. In this work, we proposed an ultrasensitive electrochemical hydroquinone biosensor relying on a nano-architecture of oriented Prussian blue/Polyaniline (PB/PANI) nanoarrays, which can achieve precise and specific detection within only 15 s. The oriented nanoarray architecture of the PANI was in-situ constructed on a carbon cloth substrate to shorten the electron pathway. To overcome the poor electrocatalysis of PANI, the well-defined PB nanocubes were exactly synthetized on those PANI to construct a novel PB/PANI nanostructure. This special nanostructure enables to arouse strong synergistic effects owning both excellent electrocatalysis and conductivity derived from PB and PANI, along with a remarkably high surface area to create abundant active sites for the laccase immobilization. After the immobilization of laccase, the as-prepared biosensor performs a high sensitivity of 931.39 μA mM⁻¹ cm⁻², together with outstanding detection limit of 250 nM (0.027 ppm) and reliability in the analysis of real lake samples.