A colorimetric sensor array of porous pigments.
The development of a low-cost, simple colorimetric sensor array capable of the detection and identification of toxic gases is reported. This technology uses a disposable printed array of porous pigments in which metalloporphyrins and chemically-responsive dyes are immobilized in a porous matrix of organically modified siloxanes (ormosils) and printed on a porous membrane. The printing of the ormosil into the membrane is highly uniform and does not lessen the porosity of the membrane, as shown by scanning electron microscopy. When exposed to an analyte, these pigments undergo reactions that result in well-defined color changes due to strong chemical interactions: ligation to metal ions, Lewis or Brønsted acid-base interactions, hydrogen bonding, etc. Striking visual identification of 3 toxic gases has been shown at the IDLH (immediately dangerous to life and health) concentration, at the PEL (permissible exposure level), and at a level well below the PEL. Identification and quantification of analytes were achieved using the color change profiles, which were readily distinguishable in a hierarchical clustering analysis (HCA) dendrogram, with no misclassifications in 50 trials.
Lim
Sung H
SH
iSense, LLC, 470 Ramona St., Palo Alto, CA 94301, USA.
Kemling
Jonathan W
JW
Feng
Liang
L
Suslick
Kenneth S
KS
D000393:Air Pollutants / Q000032:analysis*; D000641:Ammonia / Q000737:chemistry; D002713:Chlorine / Q000737:chemistry; D003124:Colorimetry / Q000295:instrumentation* / Q000379:methods; D004396:Coloring Agents / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D012680:Sensitivity and Specificity; D013458:Sulfur Dioxide / Q000737:chemistry; D013997:Time Factors
D000393:Air Pollutants; D004396:Coloring Agents; D005740:Gases; D008567:Membranes, Artificial; D013458:Sulfur Dioxide; D002713:Chlorine; D000641:Ammonia