title: Inkjet-printed gold nanoparticle electrochemical arrays on plastic. Application to immunodetection of a cancer biomarker protein.
abstract: Electrochemical detection combined with nanostructured sensor surfaces offers potentially low-cost, high-throughput solutions for detection of clinically significant proteins. Inkjet printing offers an inexpensive non-contact fabrication method for microelectronics that is easily adapted for incorporating into protein immunosensor devices. Herein we report the first direct fabrication of inkjet-printed gold nanoparticle arrays, and apply them to electrochemical detection of the cancer biomarker interleukin-6 (IL-6) in serum. The gold nanoparticle ink was printed on a flexible, heat resistant polyimide Kapton substrate and subsequently sintered to create eight-electrode arrays costing <0.2 euro per array. The inkjet-printed working electrodes had reproducible surface areas with RSD <3%. Capture antibodies for IL-6 were linked onto the eight-electrode array, and used in sandwich immunoassays. A biotinylated secondary antibody with 16-18 horseradish peroxidase labels was used, and detection was achieved by hydroquinone-mediated amperometry. The arrays provided a clinically relevant detection limit of 20 pg mL(-1) in calf serum, sensitivity of 11.4 nA pg(-1) cm(-2), and a linear dynamic range of 20-400 pg mL(-1).
authors.affiliation: Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, CT 06269-3060, USA.
authors.forename: Gary C
authors.initials: GC
authors.lastname: Jensen
authors.forename: Colleen E
authors.initials: CE
authors.lastname: Krause
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Sotzing
authors.forename: James F
authors.initials: JF
authors.lastname: Rusling
mesh_terms: D000818:Animals; D001555:Benzene Derivatives / Q000737:chemistry; D014408:Biomarkers, Tumor / Q000097:blood*; D002417:Cattle; D004563:Electrochemistry / Q000295:instrumentation*; D006046:Gold / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D007281:Ink; D015850:Interleukin-6 / Q000097:blood*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D036103:Nanotechnology; D010969:Plastics / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011327:Printing
chemical_list: D001555:Benzene Derivatives; D014408:Biomarkers, Tumor; D015850:Interleukin-6; D010969:Plastics; D011108:Polymers; C513053:polyamic acid; D006046:Gold