Researchers have designed gold nanoparticles-based detector to sniff out traces of DDT (dichlorodiphenyltrichloroethane), a harmful organochlorine pesticide in food and environmental samples1.
The researchers conjugated gold nanoparticles (GNPs) to anti-DDT antibodies, which are the detecting agent. An antigen (DDA-BSA conjugate) was smeared on to a nitro cellulose (NC) membrane containing strip.
The conjugates were treated with different concentrations of free DDT to form an immunocomplex. This immunocomplex solution was further reacted with the antigen immobilized NC membrane containing strips.
The change in the intensity of red colour (due to GNPs) in the detection zone of NC membrane containing strips indicated the varying concentrations of DDT. The maximum intensity of red colour was at zero DDT concentration. The lowest detection limit of DDT was determined to be 27 nanogram. The dipstick technique based on GNPs is suitable for the detection of several toxins in food and environmental samples and can be applied for rapid on-site testing of pesticides, the researchers say.
