title: Field-based detection and monitoring of uranium in contaminated groundwater using two immunosensors.
abstract: Field-based monitoring of environmental contaminants has long been a need for environmental scientists. Described herein are two kinetic exclusion-based immunosensors, a field portable sensor (FPS) and an inline senor, that were deployed at the Integrated Field Research Challenge Site of the U.S. Department of Energy in Rifle, CO. Both sensors utilized a monoclonal antibody that binds to a U(VI)-dicarboxyphenanthroline complex (DCPI in a kinetic exclusion immunoassay format These sensors were able to monitor changes of uranium in groundwater samples from approximately 1 microM to below the regulated drinking water limit of 126 nM (30 ppb). The FPS is a battery-operated sensor platform that can determine the uranium level in a single sample in 5-10 min, if the instrument has been previously calibrated with standards. The average minimum detection level (MDL) in this assay was 0.33 nM (79 ppt), and the MDL in the sample (based on a 1:200-1:400 dilution) was 66-132 nM (15.7-31.4 ppb). The inline sensor, while requiring a grounded power source, has the ability to autonomously analyze multiple samples in a single experiment The average MDL in this assay was 0.12 nM (29 ppt), and the MDL in the samples (based on 1:200 or 1:400 dilutions) was 24-48 nM (5.7-11.4 ppb). Both sensor platforms showed an acceptable level of agreement (9 = 0.94 and 0.76, for the inline and FPS, respectively) with conventional methods for uranium quantification.
authors.affiliation: Department of Biochemistry, Tulane University School of Medicine, New Orleans, Louisiana 70112, Lawrence Berkeley, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Melton
authors.forename: Haini
authors.initials: H
authors.lastname: Yu
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Williams
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Morris
authors.forename: Philip E
authors.initials: PE
authors.lastname: Long
authors.forename: Diane A
authors.initials: DA
authors.lastname: Blake
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry; D005618:Fresh Water / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods; D009942:Organometallic Compounds / Q000737:chemistry; D010618:Phenanthrolines / Q000737:chemistry; D011834:Radiation Monitoring / Q000295:instrumentation / Q000379:methods*; D014501:Uranium / Q000032:analysis*; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: C518489:2,9-dicarboxy-1,10-phenanthroline; D000911:Antibodies, Monoclonal; D009942:Organometallic Compounds; D010618:Phenanthrolines; D014875:Water Pollutants, Radioactive; C005460:uranyl acetate; D014501:Uranium