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 mm2 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.

Evaluating Metabolite-Related DNA Oxidation and Adduct Damage from Aryl Amines Using a Microfluidic ECL Array

“…Microwells were printed from toner ink using a laser printer onto glossy paper as neat transferred to the PG, providing 2 mm diameter wells 10–15 nm deep. 26 The PDMS channel and PG chip (Schemes 2C, D) were positioned between two machined poly(methyl methacrylate) (PMMA) plates and screwed together to provide two sealed microfluidic channels (Scheme 2). Each microwell can hold a 1.0 ± 0.1 μ L aqueous droplet, and the toner serves as a hydrophobic barrier to prevent cross-contamination during film deposition.…”

Digital versatile disc bipolar electrode: A fast and low-cost approach for visual sensing of analytes and electrocatalysts screening

“…This cheap substrate has also attracted attention for designing microfluidic and lab on chip devices [31][32][33]. Recently, the capability of using Ag electrodes manufactured from silver CD and DVD for the determination of hydrogen peroxide in traditional electrochemical setup have been investigated [34][35][36].…”

Cheap and disposable gold and silver electrodes: Trends in the application of compact discs and digital versatile discs for electroanalytical chemistry

“…The unused electrode areas were then masked with varnish. Repetitive injections (n = 10) of a mixture containing iodide, ascorbic acid, dipyrone, and acetaminophen (20,200, 500, and 100 µM), were found to give relative standard deviations of 2.9, 4.5, 6.1, and 4.0 %, respectively.…”

“…The low cost the disc means they can be, if needed, treated as disposable one shot devices. Further modifications can also be made by techniques such as laser [14] and inkjet printing [12,15,16] or by the heat transfer of toner masks [17][18][19][20][21][22][23] designs onto the metal surface. Other alternative methods for the economic fabrication of electrodes exist and have been widely used and…”