Complete fabrication of a nonenzymatic glucose sensor with a wide linear range for the direct testing of blood samples

Abstract

A scalable method for the fabrication of a nonenzymatic disposable blood glucose sensor was made possible by preparing large quantities of catalytic materials and using screen-printing technology. The copper-aluminium double hydroxide microspheres were synthesized by urea hydrolysis method using sulfate salts of aluminium and copper at 100 °C for 24 h. Morphological studies revealed the presence of novel coral-like copper-aluminium microspheres. The prepared compound was used for the fabrication of an electrochemical glucose sensor by screen-printing. The sensor tested in 0.15 M NaOH medium showed a sensitivity of 1111.15 ± 7.96 µA mM-1 cm-2, linear response up to 27 mM glucose concentrations and a limit of detection of 17.60 ± 0.13 µM (S/N = 3). In the presence of exogenous and endogenous interfering species, the fabricated sensor was found to be selective towards glucose. A laboratory prototype of the sensor strip was fabricated using a cellulose membrane, hydrophilic membrane, and customized adhesive layers. The prototype was calibrated and tested with whole blood samples and obtained results are highly correlative with the commercial glucose sensor strips. The sensitivity of the prototype was found to be 0.3057 ± 0.02 µA mM−1 cm−2 with a linear range upto 24.44 mM (440 mg dL−1) and a calculated LOD of 0.9873 ± 0.06 mM (17.77 ± 1.11 mg dL−1). The ease of fabrication method and the reliability of the results with real blood samples show the potential of the nonenzymatic blood glucose sensor prototype for industrial fabrication.