Development of nanomechanical biosensors for detection of the pesticide DDT.
We report the use of a novel technique for detection of the organochlorine insecticide compound dichlorodiphenyltrichloroethane (DDT) by measuring the nanometer-scale bending of a microcantilever produced by differential surface stress. A synthetic hapten of the pesticide conjugated with bovine serum albumin (BSA) was covalently immobilised on the gold-coated side of the cantilever by using thiol self assembled monolayers. The immobilisation process is characterised by monitoring the cantilever deflection in real-time. Then specific detection is achieved by exposing the cantilever to a solution of a specific monoclonal antibody to the DDT hapten derivative. The specific binding of the antibodies on the cantilever sensitised side is measured with nanomolar sensitivity. Direct detection is proved by performing competitive assays, in which the cantilever is exposed to a mixed solution of the monoclonal antibody and DDT. The future prospects and limitations to be overcome for the application of nanomechanical sensors for pesticide detection are discussed.
Alvarez
Mar
M
Biosensor Group Centro, Instituto de Microelectrónica de Madrid (CNM-CSIC), Conscjo Superior de, Investigaciones Cienti;ficas, Centro Nacional de Microelectronica, Isaac Newton 8 (PTM), Tres Cantos, 28760, Madrid, Spain.
Calle
Ana
A
Tamayo
Javier
J
Lechuga
Laura M
LM
Abad
Antonio
A
Montoya
Angel
A
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D003634:DDT / Q000032:analysis* / Q000737:chemistry* / Q000276:immunology; D004548:Elasticity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D006241:Haptens / Q000737:chemistry / Q000276:immunology; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D010575:Pesticides / Q000032:analysis; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000276:immunology; D013314:Stress, Mechanical
D006241:Haptens; D010575:Pesticides; D012710:Serum Albumin, Bovine; D003634:DDT