Enhancing H2O2 and glucose double detection by surface microstructure regulation of Brussels sprout-like Ni–Co(OH)2/rGO/carbon cloth composites

Abstract

Surface microstructure regulation is an effective way to enhance the performance of sensing materials. Here, a hierarchical and flexible Brussels sprout-like Ni–Co(OH)₂/rGO/carbon cloth (CC) composite was constructed by optimizing the morphology of Ni–Co(OH)₂ microspheres and the addition amount of rGO. This sensor shows excellent reproducibility, high selectivity, and good stability. It shows a high sensitivity of 3.7391 mA mM⁻¹ cm⁻² in the 0.0388–124.0436 mM line detection range for H₂O₂ and 1.8457 mA mM⁻¹ cm⁻² in the 0.0300–2.0000 mM line detection range for glucose. The low limits of detection for H₂O₂ and glucose are 2.316 nM and 0.115 μM, respectively. The excellent electrochemical performance of the Ni–Co(OH)₂/rGO/CC composite is attributed to its unique Brussels sprout-like microstructure. By studying the electrical conductivity, electrochemical active surface area, and hydrophilic–hydrophobic surfaces of the Ni–Co(OH)₂/rGO/CC composite, the structure–performance relationship between the microstructure and sensing performance of the composite was further clarified. Moreover, the mechanism of CC, rGO, and the Ni–Co(OH)₂ ternary composite in the sensing process is proposed. This study provides a new strategy for the construction of flexible wearable electrodes with high sensitivity.