title: Fabrication of immunosensor microwell arrays from gold compact discs for detection of cancer biomarker proteins.
abstract: A simple method is reported to fabricate gold arrays featuring microwells surrounding 8-electrodes from gold compact discs (CDs) for less than $0.2 per chip. Integration of these disposable gold CD array chips with microfluidics provided inexpensive immunoarrays that were used to measure a cancer biomarker protein quickly at high sensitivity. The gold CD sensor arrays were fabricated using thermal transfer of laserjet toner from a computer-printed pattern followed by selective chemical etching. Sensor elements had an electrochemically addressable surface area of 0.42 mm(2) with RSD <2%. For a proof-of-concept application, the arrays were integrated into a simple microfluidic device for electrochemical detection of cancer biomarker interleukin-6 (IL-6) in diluted serum. Capture antibodies of IL-6 were chemically linked onto the electrode arrays and a sandwich immunoassay protocol was developed. A biotinylated detection antibody with polymerized horseradish peroxidase labels was used for signal amplification. The detection limit of IL-6 in diluted serum was remarkably low at 10 fg mL(-1) (385 aM) with a linear response with log of IL-6 concentration from 10 to 1300 fg mL(-1). These easily fabricated, ultrasensitive, microfluidic immunosensors should be readily adapted for sensitive detection of multiple biomarkers for cancer diagnostics.
authors: Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269-3060, USA.
authors: Chi K
authors: CK
authors: Tang
authors: Abhay
authors: A
authors: Vaze
authors: James F
authors: JF
authors: Rusling
mesh_terms: D000906:Antibodies / Q000276:immunology; D014408:Biomarkers, Tumor / Q000097:blood*; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D015850:Interleukin-6 / Q000097:blood / Q000276:immunology; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation; D019904:Polymethyl Methacrylate / Q000737:chemistry
chemical_list: D000906:Antibodies; D014408:Biomarkers, Tumor; D004129:Dimethylpolysiloxanes; D015850:Interleukin-6; C013830:baysilon; D006046:Gold; D019904:Polymethyl Methacrylate