Objet24 3d printer

The ultrapure deionized water (18.2 MΩ·cm) was produced from Millipore Advantage A10 (Billerica, MA, USA. Phosphate-buffered saline solution (P5493, PBS, 10 times concentrated, diluted 10:1 by deionized water) was purchased from Sigma Aldrich (St. Louis, MO, USA). Bovine serum albumin (BSA) for blocking the channel was purchased from EM Science (Gibbstown, NJ, USA). Absolute ethanol for washing was purchased from Sinopharm (Beijing, China). The magnetic silica beads with a diameter of ≈1 μm for capturing the DNA were purchased from Huier Nano (HRXJ-0030, Zhengzhou, China). The nucleic acid detection kit, including reaction mixes, Taqman probes, and primers, for Escherichia coli (BD-1-210-1), Vibrio parahaemolyticus (BD-1-205), Listeria monocytogenes (BD-1-303), Salmonella typhimurium (BD-1-201-1), Staphylococcus aureus (BD-1-105), Campylobacter jejuni (BD-1-204-1), and Bacillus cereus (BD-1-420) were purchased from Huirui Biotech (Shanghai, China). The polydimethylsiloxane (PDMS) for fabricating the extraction chip was purchased from Dow Corning (Sylgard 184, Auburn, MI, USA). The PDMS membrane for bonding was purchased from Rogers (HT-6240, Carol Stream, IL, USA). The Objet24 3D printer and the material (VeroWhite plus RGD835) for printing the mold of the extraction chip were purchased from Stratasys (Eden Prairie, MN, USA).

The polyclonal antibodies against salmonella purchased from Abcam (ab69255, Cambridge, MA, USA) were used for specifically reacting with salmonella typhimurium. The carboxyl modified magnetic nanoparticles with an average diameter of 150 nm and a Fe concentration of 1 mg/mL were obtained from Ocean Nanotech (San Diego, CA, USA) for immunomagnetic separation. Phosphate-buffered saline solution (PBS, P5493, 10 times concentrated) from Sigma Aldrich (St. Louis, MO, USA) was 10 times diluted with deionized water to prepare the PBS solution (pH 7.4, 0.01 M). Tween-20 purchased from Amresco (Solon, OH, USA) was used for washing. Luria-Bertani (LB) medium (Aoboxing Biotech, Beijing, China) was used for bacteria culture. Bovine serum albumin (BSA) from EM Science (Gibbstown, NJ, USA) was used for blocking. All the solutions were prepared with deionized water produced by Advantage A10 from Millipore (Burlington, MA, USA).
The silicone elastomer kit from Dow Corning (Sylgard 184, Auburn, MI, USA) was used for fabricating the fluidic chip. The Objet24 3D printer and the printing material (VeroWhite plus RGD835) from Stratasys (Eden Prairie, MN, USA) were used for fabricating the mold of the fluidic chip.