Three-dimensional porous Cu@Cu.sub.2O aerogels for direct voltammetric sensing of glucose

• Published in: Mikrochimica acta (1966) Vol. 186; no. 3
• Main Authors: Gao, Yajun, Yang, Feiyu, Yu, Qianhui, Fan, Rui, Yang, Ming, Rao, Shengqi, Lan, Qingchun
• Format: Journal Article
• Language: English
• Published: Springer 01.03.2019
• Subjects: Dextrose; Enzymes; Glucose; Sensors
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-019-3263-6

Three-dimensional Cu@Cu.sub.2O aerogels with excellent electrocatalytic activity were prepared and used as electrode matrix for constructing novel electrochemical glucose sensors. The aerogels were obtained by adding a fresh solution of NaBH.sub.4 into a mixture of CuCl.sub.2 and NaOH aqueous solutions under stirring at room temperature. The aerogels were assembled with Cu or Cu.sub.2O nanoparticles. The materials show superfine spongy-like structures with large surface-to-volume ratio, numerous active sites and good solubility. The Cu@Cu.sub.2O aerogels show highly efficient electrochemical activity toward glucose oxidation with a relatively low-onset potential (0.25 V) in 0.1 M NaOH solution. This non-enzymatic glucose sensor offers a low detection limit of 0.6 [mu]M (S/N = 3), a high sensitivity (195 mA M.sup.-1 cm.sup.-2), and two wide linear ranges (0.001-5.2 mM, 5.2-17.1 mM) at a working voltage of 0.6 V (vs. Ag/AgCl) in alkaline solution. While in neutral pH values, the respective data are a linear analytical range from 0.1 to 10 mM; a detection limit of 54 [mu]M (S/N = 3) and a sensitivity of 12 mA M.sup.-1 cm.sup.-2 at scan rate of 100 mV s.sup.-1. The sensor possesses high selectivity, good reproducibility and long-time stability. It was utilized to determine glucose levels in (spiked) human serum samples, and satisfactory results were obtained.