Gold-dispersed hierarchical flower-like copper oxide microelectrodes for the sensitive detection of glucose and lactic acid in human serum and urine

Herein, we report self-supported gold-dispersed copper oxide microflowers (Au@CuO MFs) on copper microelectrodes (CMEs) as a sensitive platform for the sensing of glucose and lactic acid in human serum and urine samples. The direct growth of a new class of gold-dispersed copper oxide microflowers on Cu microelectrodes involves growing flower-like passivated copper microelectrodes in nitric acid followed by the galvanic replacement of copper atoms with gold atoms without employing any surfactant or polymer or without the use of any catalysts or complicated procedures. The as-fabricated gold-dispersed copper oxide microflower microelectrodes (Au@CuO MFs|CME) were employed as potential signal transducers for the sensitive detection of glucose and lactic acid in practical samples. The present Au@CuO MFs|CME microsensor demonstrates an extensive linear detection range from 5.0 mu M to 0.5 mM for glucose with a low limit of detection (LOD) of similar to 1.41 mu M and a sensitivity of similar to 4.14 mA mu M-1 cm(-2), and from 100 nM to 88.0 mu M for lactic acid with a LOD of similar to 27.0 nM and a sensitivity of similar to 6.19 mA mu M-1 cm(-2). The present multi-functional nanoarchitectured Au@CuO MFs|CME microsensor is anticipated to offer unique surface characteristics and synergistic effects, and can be exploited in various electrochemical fields.

Automated summary

In this research, self-supported gold-dispersed copper oxide microflowers on copper microelectrodes were used as a sensitive platform for detecting glucose and lactic acid in human serum and urine samples. This novel microsensor was fabricated by growing flower-like passivated copper microelectrodes in nitric acid and then replacing copper atoms with gold atoms without using any surfactant, polymer, catalyst, or complicated procedures. The microsensor demonstrated an extensive linear detection range and low limit of detection for glucose and lactic acid, making it a promising tool for electrochemical applications.