NiFe PBA nanocube as both anode and cathode catalysts for enzyme-free fuel cell-based self-powered sensor to detect catechol or hydroquinone

NiFe PBA exhibits laccase-mimic for ORR and electrocatalyze oxidation of CC and HQ. • A self-powered sensor by assembling NiFe PBA as both anode and cathode catalyst. • The sensor capable of detecting CC or HQ in simulated wastewater satisfactorily. Biofuel cells are widely applied in designing self-powered sensors (SPS) due to their rich fuel source, environmental friendliness, and advantages in operating under neutral pH and room temperatures. However, they are limited by inherent drawbacks of biological enzymes as catalysts, such as poor stability and high costs, greatly restricting their real applications. Herein we report on NiFe Prussian blue analogue (PBA) nanocubes with good mimicking laccase activity, which can not only exhibit excellent oxygen reduction reaction in the absence of electron mediators, but also efficiently electrocatalyze the oxidation of phenolic fuels. Subsequently, a dual-chamber enzyme-free fuel cell was constructed using NiFe PBA as both the anode and cathode catalysts as well as catechol (CC)/hydroquinone (HQ) as the fuel. Based on this, a SPS was developed to detect CC or HQ. The maximum power density ( P max ) of the HQ-fueled sensor is linear within 0.5 μM–5 mM HQ in three parts. Similarly, the P max for CC-fueled sensor is linear with 5 μM–5 mM CC in three parts. Moreover, the sensor has excellent selectivity and is capable of monitoring simulated wastewater. Thus, this work demonstrates an efficient enzyme-free biofuel cells based SPS using the same nanomaterial as anode and cathode catalyst. Download: Download high-res image (271KB) Download: Download full-size image