Alkaline-promoted regulation of the peroxidase-like activity of Ni/Co LDHs and development bioassays

Publication date: Available online 8 January 2019

Source: Talanta

Author(s): Li Su, Xinai Yu, Yuqi Miao, Guojiang Mao, Wenpei Dong, Suling Feng, Siman Liu, Like Yang, Kaige Zhang, Hua Zhang

Abstract

Nanozymes' activities could be regulated by a simple and effective pH change in an in situ manner. In this work, for the first time, the peroxidase-like activity of Ni/Co layered double hydroxides (LDHs) was regulated via the alkaline-promoted reaction of fluorogenic substrate homovanillic acid and H₂O₂, and a promising tool for pH sensing was developed over the pH range of 8.3-9.6. As peroxidase nanozyme model, Ni/Co LDHs showed ease of preparation, low-cost, and water-solubility, which played an important role in this luminescence system. Based on the pH-dependent regulation of the Ni/Co LDHs activity, we constructed the bioassay platform for the determination urea, urease, penicillin G, and penicillinase with a wide linear range of 17-1000 µM, 3.3-270 mU mL⁻¹, 3.3-1300 µM and 3.3-100 mU mL⁻¹, respectively. This study not only demonstrated the alkaline-promoted modulation the nanozymes' activities, but also established a facile approach to develop novel bioassays.

Graphical abstract

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