Adeel M(1)(2), Canzonieri V(2)(3), Daniele S(1), Vomiero A(4)(5), Rizzolio F(6)(7), Rahman MM(8).

Affiliation

Adeel M(1)(2), Canzonieri V(2)(3), Daniele S(1), Vomiero A(4)(5), Rizzolio F(6)(7), Rahman MM(8).
Author information:
(1)Department of Molecular Sciences and Nanosystems, Ca'Foscari University of Venice, 30172, Venice-Mestre, Italy.
(2)Pathology Unit, Centro di Riferimento Oncologico di Aviano
(CRO) IRCCS, 33081, Aviano, Italy.
(3)Department of Medical, Surgical and Health Sciences, University of Trieste, 34127, Trieste, Italy.
(4)Department of Molecular Sciences and Nanosystems, Ca'Foscari University of Venice, 30172, Venice-Mestre, Italy. [Email]
(5)Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-97187, Luleå, Sweden. [Email]
(6)Department of Molecular Sciences and Nanosystems, Ca'Foscari University of Venice, 30172, Venice-Mestre, Italy. [Email]
(7)Pathology Unit, Centro di Riferimento Oncologico di Aviano
(CRO) IRCCS, 33081, Aviano, Italy. [Email]
(8)Department of Energy and Materials, Konkuk University, Chungju, 27478, Republic of Korea. [Email]

Abstract

The synthesis of Co-based two-dimensional (2D) metal azolate framework nanosheets (MAF-5-CoII NS) is described using a simple hydrothermal method. The product was isostructural to MAF-5 (Zn). The as-prepared MAF-5-CoII NS exhibited high surface area (1155 m2/g), purity, and crystallinity. The MAF-5-CoII NS-modified screen-printed electrode (MAF-5-CoII NS/SPE) was used for nonenzymatic detection of glucose in diluted human blood plasma (BP) samples with phosphate buffer saline (PBS, pH 7.4) and NaOH (0.1 M, pH 13.0) solutions. The MAF-5-CoII NS nanozyme displayed good redox activity in both neutral and alkaline media with the formation of CoII/CoIII redox pair, which induced the catalytic oxidation of glucose. Under the optimized detection potential, the sensor presented a chronoamperometric current response for the oxidation of glucose with two wide concentration ranges in PBS-diluted (62.80 to 180 μM and 305 to 8055 μM) and NaOH-diluted (58.90 to 117.6 μM and 180 to 10,055 μM) BP samples, which were within the limit of blood glucose levels of diabetic patients before (4.4-7.2 mM) and after (10 mM) meals (recommended by the American Diabetes Association). The sensor has a limit of detection of ca. 0.25 and 0.05 μM, respectively, and maximum sensitivity of ca. 36.55 and 1361.65 mA/cm2/mM, respectively, in PBS- and NaOH-diluted BP samples. The sensor also displayed excellent stability in the neutral and alkaline media due to the existence of hydrophobic linkers (2-ethyl imidazole) in the MAF-5-CoII NS, good repeatability and reproducibility, and interference-free signals. Thus, MAF-5-CoII NS is a promising nanozyme for the development of the disposable type of sensor for glucose detection in human body fluids. Graphical abstract.