Trace detection of picloram using an electrochemical immunosensor based on three-dimensional gold nanoclusters.
Picloram, a herbicide widely used for broadleaf weed control, is persistent and mobile in soil and water with adverse health and environmental effects. It is important to develop a sensitive method for accurate detection of trace picloram in the environment. In this article, a type of ordered three-dimensional (3D) gold (Au) nanoclusters obtained by two-step electrodeposition using the spatial obstruction/direction of the polycarbonate membrane is reported. Bovine serum albumin (BSA)-picloram was immobilized on the 3D Au nanoclusters by self-assembly, and then competitive immunoreaction with picloram antibody and target picloram was executed. The horseradish peroxidase (HRP)-labeled secondary antibody was applied for enzyme-amplified amperometric measurement. The electrodeposited Au nanoclusters built direct electrical contact and immobilization interface with protein molecules without postmodification and positioning. Under the optimal conditions, the linear range for picloram determination was 0.001-10 μg/ml with a correlation coefficient of 0.996. The detection and quantification limits were 5.0 × 10(-4) and 0.0021 μg/ml, respectively. Picloram concentrations in peach and excess sludge supernatant extracts were tested by the proposed immunosensor, which exhibited good precision, sensitivity, selectivity, and storage stability.
Chen
Lijuan
L
College of Environmental Science and Engineering, Hunan University, Changsha 410082, China.
Zeng
Guangming
G
Zhang
Yi
Y
Tang
Lin
L
Huang
Danlian
D
Liu
Can
C
Pang
Ya
Y
Luo
Jie
J
D000818:Animals; D015374:Biosensing Techniques / Q000379:methods; D002417:Cattle; D055664:Electrochemical Techniques / Q000379:methods*; D004595:Electroplating; D006046:Gold / Q000737:chemistry*; D006540:Herbicides / Q000032:analysis*; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010846:Picloram / Q000032:analysis*; D027861:Prunus / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry
D006540:Herbicides; D012710:Serum Albumin, Bovine; D006046:Gold; D010846:Picloram