3D Prussian blue/Pt decorated carbon nanofibers based screen-printed microchips for the ultrasensitive hydroquinone biosensing

Nowadays, water pollution has become more serious, greatly affecting human life and healthy. Electrochemical biosensor, a novel and rapid detection technique, plays an important role in the real-time and trace detection of water pollutants. However, the stability and sensitivity of electrochemical biosensors remain a great challenge for practical detections in real samples to the strong interferences derived from complex components and coagulation effects. In this work, we reported a novel three-dimensional architecture of Prussian blue nanoparticles (PBNPs)/ Pt nanoparticles (PtNPs) composite film, using 3D interweaved carbon nanofibers as a supporting matrix, for the construction of screen-printed microchips-based biosensor. PtNPs with diameters of ~2.5 nm was highly dispersed on the carbon nanofibers (CNFs) to build a 3D skeleton nanostructure through a solvothermal reduction. Subsequently, uniform PBNPs were in-situ self-assembled on this skeleton to construct a 3D architecture of PB/Pt-CNF composite film. Due to the synergistic effects derived from this special feature, the as-prepared hydroquinone (HQ) biosensor chips can synchronously promote both surface area and conductivity to greatly enhance the electrocatalysis from enzymatic reaction. This biosensor has exhibited a high sensitivity of 220.28 μA·L·mmol⁻¹·cm⁻² with an ultrawide linear range from 2.5 μmol·L⁻¹ to 1.45 mmol·L⁻¹ at a low potential of 0.15 V, as well as the satisfactory reproducibility and usage stability. Besides, its accuracy was also verified in the assays of real water samples. It is highly expected that the 3D PB/Pt-CNF based screen-printed microchips will have wide applications in dynamic monitoring and early warning of analytes in the various practical fields.