Evidence map›Paper›PMID 24060606›Full record

ArticleJournal of the American Chemical Society2013

Chemical analog-to-digital signal conversion based on robust threshold chemistry and its evaluation in the context of microfluidics-based quantitative assays.

Toan Huynh, Bing Sun, Liang Li, Kevin P Nichols, Jay L Koyner, Rustem F Ismagilov

Open access · greenAbstract readEvaluation Study
In one paragraph

Article in Journal of the American Chemical Society, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
3.9field-weighted citation impact, top 7% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed, 25 citations in OpenAlex.

  1. Review
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 2 institutions in 1 country.

Toan HuynhDepartment of Chemistry and Institute for Biophysical Dynamics, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
Bing Sun
Liang Li
Kevin P Nichols
Jay L Koyner
Rustem F Ismagilov
University of Chicago · USCalifornia Institute of Technology · US

Funding

2007 NIH Director's Pioneer Award Program (DP1)DP1OD003584 · OD · UNIVERSITY OF CHICAGO · PI ISMAGILOV, RUSTEM F · 2007 to 2011
$3.9M
The Role of Cystatin C in Acute Kidney InjuryK23DK081616 · NIDDK · UNIVERSITY OF CHICAGO · PI KOYNER, JAY L · 2009 to 2013
$718k
NCCDPHP CDC HHS DP10D003584NIDDK NIH HHS K23 DK081616NIDDK NIH HHS K23DK081616NIDDK NIH HHS L30 DK084760NIH HHS DP1 OD003584
6 · The paper itself

Abstract

In this article, we describe a nonlinear threshold chemistry based on enzymatic inhibition and demonstrate how it can be coupled with microfluidics to convert a chemical concentration (analog input) into patterns of ON or OFF reaction outcomes (chemical digital readout). Quantification of small changes in concentration is needed in a number of assays, such as that for cystatin C, where a 1.5-fold increase in concentration may indicate the presence of acute kidney injury or progression of chronic kidney disease. We developed an analog-to-digital chemical signal conversion that gives visual readout and applied it to an assay for cystatin C as a model target. The threshold chemistry is based on enzymatic inhibition and gives sharper responses with tighter inhibition. The chemistry described here uses acetylcholinesterase (AChE) and produces an unambiguous color change when the input is above a predetermined threshold concentration. An input gives a pattern of ON/OFF responses when subjected to a monotonic sequence of threshold concentrations, revealing the input concentration at the point of transition from OFF to ON outcomes. We demonstrated that this threshold chemistry can detect a 1.30-fold increase in concentration at 22 °C and that it is robust to experimental fluctuations: it provided the same output despite changes in temperature (22-34 °C) and readout time (10-fold range). We applied this threshold chemistry to diagnostics by coupling it with a traditional sandwich immunoassay for serum cystatin C. Because one quantitative measurement comprises several assays, each with its own threshold concentration, we used a microfluidic SlipChip device to process 12 assays in parallel, detecting a 1.5-fold increase (from 0.64 (49 nM) to 0.96 mg/L (74 nM)) of cystatin C in serum. We also demonstrated applicability to analysis of patient serum samples and the ability to image results using a cell phone camera. This work indicates that combining developments in nonlinear chemistries with microfluidics may lead to development of user-friendly diagnostic assays with simple readouts.

Indexed as

AcetylcholinesteraseCholinesterase InhibitorsCystatin CEnzyme AssaysEquipment DesignHumansImmunoassayMicrofluidic Analytical TechniquesSensitivity and SpecificityAcetylcholinesteraseCholinesterase InhibitorsCystatin C

Identifiers

PMID24060606
PMCPMC3860884
OpenAlexW2141092088

What OpenQuestion holds

Textmetadata
LicenceTDM
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.