[Illinois] ECE 416 Fluorescent Beads

By Brian Cunningham

University of Illinois at Urbana-Champaign

Published on


           In this lecture, we start off talking about the luminex company and their new technology of fluorescent beads and the things it can be used for. It allows for the detection of multiple of allergies, cancer cells, and heart attack-related issues that may occur through a single blood sample. Then, we looked at the technology it runs on starting with multiplexers and how they can perform multiple test as the same time. The cytokines which are the proteins to be detected are then also discussed and how they will come into effect into the fluorescent beads. There are different types of assay multiplexing: microarrays, quantum dots, and fluorescent-labeled plastic beads. The one we are focusing on this lecture is the fluorescent-labeled plastic beads. The system it uses is a sandwich ELISA in which the analyte is to be measured between two antibodies: the capture antibody and the detection antibody. The way the beads are made is by doping them each with dyes of different concentration of 10 different intensity levels for type. Then, each bead is immobilized with a different antibody probe. Each bead needs two dyes that will absorb the same wavelength, but emit two distinct wavelengths. The sandwich assay on the surface of a fluorescently-tagged plastic bead sends two wavelengths out that detect the presence of the fluorescent dye on the bead, the third fluorescent dye tells the detection of analyte on the bead through the label on the secondary antibody. The procedure involves first putting a microplate with a well of liquid. Then, adding the beads. After the beads, the immobilized antibodies mixed with the test sample and fluorescent tagged secondary antibody tags are added. The liquid is then sucked out through a funnel and the cells are placed into a single file line and flow cytometer laser system will look send the wavelengths at them which will allow to see if a bead has been detected on the analyte. The flow cytometer also detect the label on the detect protein. The advantages and disadvantages are then looked at. A piece of example data is then analyzed and we can observe that the sensitivity really is good.


My research group is focused on the application of sub-wavelength optical phenomena and fabrication methods to the development of novel devices and instrumentation for the life sciences. The group is highly interdisciplinary, with expertise in the areas of microfabrication, nanotechnology, computer simulation, instrumentation, molecular biology, and cell biology. In particular, we are working on biosensors based upon photonic crystal concepts that can either be built from low-cost flexible plastic materials, or integrated with semiconductor-based active devices, such as light sources and photodetectors, for high performance integrated detection systems.

Using a combination of micrometer-scale and nanometer-scale fabrication tools, we are devising novel methods and materials for producing electro-optic devices with nanometer-scale features that can be scaled for low-cost manufacturing. Many of our techniques are geared for compatibility with flexible plastic materials, leading to applications such as low cost disposable sensors, wearable sensors, flexible electronics, and flexible displays. Because our structures manipulate light at a scale that is smaller than an optical wavelength, we rely on computer simulation tools such as Rigorous Coupled Wave Analysis (RCWA) and Finite Difference Time Doman (FDTD) to model, design, and understand optical phenomena within photonic crystals and related devices.

In addition to fabricating devices, our group is also focused on the design, prototyping, and testing of biosensor instrumentation for high sensitivity, portability, and resolution. Advanced instruments enable high resolution imaging of biochemical and cellular interactions with the ability to monitor images of biochemical interactions as a function of time. Using the sensors and instrumentation, we are exploring new applications for optical biosensor technology including protein microarrays, biosensor/mass spectrometry systems, and microfluidics-based assays using nanoliter quantities of reagents. The methods and systems developed in the laboratory are applied in the fields of life science research, drug discovery, diagnostic testing, and environmental monitoring. -From Professor Cunningham's Faculty Profile

Cite this work

Researchers should cite this work as follows:

  • Brian Cunningham (2013), "[Illinois] ECE 416 Fluorescent Beads," https://nanohub.org/resources/17668.

    BibTex | EndNote



University of Illinois, Urbana-Champaign, IL


NanoBio Node, Obaid Sarvana, George Michael Daley

University of Illinois at Urbana-Champaign