Congrats to Alex on Her Recent Publication

Polymer Brush-Modified Microring Resonators for Partition-Enhanced Small Molecule Chemical Detection, has been accepted for publication in Wiley-VCH's newest journal, ChemistrySelect. This article is the result of a collaboration with Paul Braun's Materials Science and Engineering group at the University of Illinois at Urbana-Champaign and introduces the idea of organically modifying our ring resonators for specific and selective detection.

Congrats to Dan on his most recent paper published in Langmuir!

Dan's most recent paper published in Langmuir. This is an extension of his previous work published last year, which demonstrated nanoporous gold (NPG) as a material with selective and tunable chemical transport properties.

Electrolyte Gradient-Based Modulation of Molecular Transport through Nanoporous Gold Membranes

Abstract

Nanopores, and nanoporous materials in general, are interesting for applications in chemical and biomolecular transport as pore sizes are on the same scale as the dimension of many (bio)chemical species. Many studies have focused on either single pores or small arrays of cylindrical pores, which are convenient in terms of their amenability toward computational modeling of transport phenomenon. However, the limited overall porosity may inhibit transport flux as well as the eventual implementation of these materials as active separation elements. Inspired by its relatively high porosity, we have explored nanoporous gold (NPG) as a membrane across which small molecular species can be transported. NPG offers a random, bicontinuous pore geometry, while also being inherently conductive and readily amenable to surface modification—attributes that may be enabling in the pursuit of size- and charge-based approaches to molecular separations. NPG was fabricated via a free-corrosion process whereby immersion of Au-containing alloys in concentrated nitric acid preferentially dissolves the less noble metals (e.g., Ni, Cu). Average pore diameters of 50 ± 20 nm were obtained as verified under scanning electron microscopy. NPG membranes were sandwiched between two reservoirs, and the selective transport of chemical species across the membrane in the presence of an ionic strength gradient was investigated. The flux of small molecules were monitored by UV–vis absorption spectrometry and found to be dependent upon the direction and magnitude of the ionic strength gradient. Moreover, transport trends underscored the effects of surface charge in a confined environment, considering that the pore diameters were on the same scale as the electrical double layer experienced by molecules transiting the membrane. Under such conditions, the transport of anions and cations through NPG was found to depend on an induced electric field as well as ion advection. Further electrical and surface chemical modulations of transport are expected to engender increased membrane functionality.

Ryan joins Analyst Editorial Board

New year, new editorial duties! Ryan has joined the Editorial Board of Analyst as as Associate Editor. As you might expect from the journal title, Analyst published high quality analytical research that fall under three broad scopes: bioanalytical, analytical nanoscience, and advanced analytical systems.

The lab has published three manuscripts in the journal including:

  • Multiplexed evaluation of capture agent binding kinetics using arrays of silicon photonic microring resonators, J.-Y. Byeon, R.C. Bailey, Analyst, 2011, 136, 3430-3433.
    DOI: 10.1039/c0an00853b
  • Photonics-on-a-Chip: Integrated Waveguides as Enabling Detection Elements for Lab-on-a-Chip Biosensing Applications, A.L. Washburn and R.C. Bailey, Analyst, 2011, 136, 227-236.
    DOI: 10.1039/C0AN00449A
  • Multiplexed Cancer Biomarker Detection Using Chip-Integrated Silicon Photonic Sensor Arrays, A.L. Washburn, W.W. Shia, K.A. Lenkeit, S.-H. Lee, R.C. Bailey Analyst, 2016, 141, 5358-5365
    DOI: 10.1039/C6AN01076H - Featured on the Cover of the Journal

Congratulations to Ryan!

ACS Central Science Highlights Technology from the Lab

Here's a snippet from the article:

Adding more tests to an instrument will necessitate new detection strategies that don’t require separating the sample into ever-tinier aliquots for each test. One promising approach came from Ryan C. Bailey, now at the University of Michigan, and Genalyte, a company he helped launch in 2007 to explore the blood-testing potential of a technology based on silicon microring resonators.
When light circulates in a cavity, the light waves that are in phase resonate, amplifying the signal. It’s the optical equivalent of rubbing a finger on the rim of a wine glass to create a resonant sound wave. Altering the volume of wine in the glass changes the pitch of the note. This concept led Bailey and his co-workers to carve picometer-wide rings into silicon chips that they stud with antibodies to blood components like proteins, nucleic acid disease markers, or pathogens. When the antibodies bind to antigens like these in a blood sample, the bound molecules change the refractive index of each ring’s resonating light and, thus, the color of the amplified light.
The technique is sensitive and inexpensive, but what is most promising about the technology to Bailey is that it can detect many antigens at a time. Genalyte’s chips each currently hold 128 rings, and a 250 μL sample “goes over all sensors in one shot”, says CEO Gunn. Clinical studies by the company show that capillary blood works as well as venous blood with the chips.
Their first target for commercialization is a chip including the 20 or so protein tests that a rheumatologist would commonly order to help diagnose autoimmune diseases such as lupus; the company is working on getting FDA approval for this device.

Click here to read the full article.

Lab Alumna, Dr. Christine Herman featured by UIUC Grad College

Check out the article here!

 

Here's an exerpt:

"What has been the most valuable transferable skill you gained from graduate school?
The most valuable transferable skill I gained from graduate school is being fearless in approaching a topic that I may know absolutely nothing about and taking steps to figure out what I need to know. In research, your goal is to break new ground in your field, and that requires first becoming aware of the current status of the field and then figuring out what open questions remain. In journalism, it's very similar in the sense that you can't be intimidated. You have to just dive right in, find the information you need and not be afraid to ask questions. I also learned perseverance and hard work. Being a researcher was the most grueling job and I have ever had, and I worked in a lab that was very supportive of having good work-life balance. I look back on those days and think about how they were really character building. That's why when people ask me if I would do it all over again and get the PhD if I had known I wanted to ultimately be a journalist, I'm torn. You certainly don't need a PhD to do what I do, but there are so many ways that the graduate school experience has really helped me.

Congrats to Richard on his recent publication!

PCR-free, Multiplexed Expression Profiling of microRNAs using Silicon Photonic Microring Resonators

R.M. Graybill, C.S. Para, R.C. Bailey Analytical Chemistry, 2016, ASAP

Abstract

We describe an approach for multiplexed microRNA analysis using silicon photonic microring resonators to detect cDNA reverse transcription products via a subsequent enzymatic signal enhancement strategy. Key to this method is a modified stem loop primer that facilitates downstream signal amplification via enzymatic turnover and improves the sensor signal 20-fold when compared to traditional stem loop primers. This approach facilitates targeted microRNA quantification in only 2.5 hours and without requiring target amplification via the polymerase chain reaction (PCR). Primers for 7 miRNA targets were orthogonally designed to avoid cross-hybridization between capture probes. This approach was applied to the detection of total RNA from human tissues and found to display differential expression profiles consistent with literature precedent. This development holds promise as an alternative to single-plex RT-qPCR methods and more expensive RNA-seq by offering a cost-effective method to analyze targeted miRNA panels in emerging diagnostic applications.