Polymerized crystalline colloidal array chemical-sensing materials for detection of lead in body fluids.
We have developed intelligent polymerized crystalline colloidal array (IPCCA) chemical-sensing materials for detection of Pb(2+) in high ionic-strength environments such as body fluids with a detection limit of <500 nmol L(-1) Pb(2+) (100 ppb). This IPCCA lead sensor consists of a mesoscopically periodic array of colloidal particles polymerized into an acrylamide hydrogel. The array Bragg-diffracts light in the visible spectral region because of the periodic spacing of the colloidal particles. This material also contains a crown ether chelating agent for Pb(2+). Chelation of Pb(2+) by the IPCCA in low-ionic-strength solutions results in a Donnan potential that swells the gel, which red-shifts the diffracted light in proportion to the Pb(2+) concentration. At high ionic strength the Donnan potential is, unfortunately, swamped and no static response occurs for these sensors. We demonstrate, however, that we can determine Pb(2+) at high ionic strength by incubating these IPCCA in a sample solution and then measuring their transient response on exposure to pure water. The non-complexed ions diffuse from the IPCCA faster than the bound Pb(2+). The resulting transient IPCCA diffraction red-shift is proportional to the concentration of Pb(2+) in the sample. These IPCCA sensors can thus be used as sensing materials in optrodes to determine Pb(2+) in high-ionic-strength solutions such as body fluids.
Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA. asher@pitt.edu
Sanford A
SA
Asher
Serban F
SF
Peteu
Chad E
CE
Reese
Xiang
X
Lin
David
D
Finegold
D020106:Acrylamide; D000818:Animals; D001774:Blood Chemical Analysis / Q000379:methods*; D001826:Body Fluids / Q000737:chemistry*; D002417:Cattle; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D003102:Colloids / Q000737:chemistry; D003460:Crystallization; D005312:Fetal Blood / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007854:Lead / Q000032:analysis* / Q000097:blood; D009994:Osmolar Concentration; D011108:Polymers / Q000737:chemistry*; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry
D003102:Colloids; D011108:Polymers; D014867:Water; D020106:Acrylamide; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007854:Lead