A handheld 3D-printed microchip for simple integration of the H2O2-producing enzymatic reactions with subsequent chemiluminescence detection: Application for sugars

• A handheld device was designed for individual detection of different sugars. • Pumpless microchip with new cone-shape blocking valves was fabricated by 3D printing. • Specific enzymes for each sugar were embedded into ZIF-8 to improve stability. • 2D ZIF-67 catalyzed chemiluminescence reaction was applied for detection. • The device showed satisfactory results for real-time monitoring of sugars in foods. Herein, a novel lab-on-a-chip (LoC) device fabricated by 3D printing based on H 2 O 2 -producing enzymatic reactions with sensitive chemiluminescence (CL) detection was developed to measure different sugars, including glucose, fructose, sucrose, and maltose, in honey, juice, and rice flour samples. The pumpless microchip included two main parts, separated by new cone-shape blocking valves; part A for sample introduction and subsequent enzymatic reaction, besides the CL reagent (luminol) container, and part B for detection. The specific enzyme(s) were embedded into the pores of the zinc zeolite-imidazole framework (ZIF-8) to improve their storage stability. By opening the valves, H 2 O 2 produced by enzymatic reaction and luminol could flow through the designed channels into the detection zone on part B, where a 2D cobalt-imidazole framework was embedded to improve the luminol-H 2 O 2 CL emission. The obtained signal was proportional to the considered sugar concentration, with the detection limits range of 20–268 µM.