title: Development of gold nanoparticles-based aptasensor for the colorimetric detection of organophosphorus pesticide phorate.
abstract: The present study reports a highly simple and rapid method for the detection of a widely used and extremely toxic organophosphorus pesticide, phorate. The detection employs a pesticide-specific aptamer as the recognition element and gold nanoparticles as the optical sensors. The aptamer, owing to its random coil structure, provides stability to the gold nanoparticles upon linking, thereby keeping the nanoparticles well dispersed. However, on the addition of the target pesticide, the aptamer acquires a rigid conformation resulting in the aggregation of the gold nanoparticles. Consequently, the color of the solution changes from red to blue and is easily observable with the naked eye. The proposed method was linear in the concentration range of 0.01 nM to 1.3 μm with the limit of detection as low as 0.01 nM. Moreover, the proposed assay selectively recognized phorate in the presence of other interfering substances and, thus, can be applied to real samples for the rapid and efficient screening of phorate.
authors.affiliation: Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Sector-14, Chandigarh, 160014, India.
authors.forename: Rajni
authors.initials: R
authors.lastname: Bala
authors.affiliation: Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Sector-14, Chandigarh, 160014, India. rohitksg@pu.ac.in.
authors.forename: Rohit K
authors.initials: RK
authors.lastname: Sharma
authors.affiliation: Department of Applied Sciences, University Institute of Engineering and Technology (U.I.E.T.), Panjab University, Sector-25, Chandigarh, 160014, India. nishima@pu.ac.in.
authors.forename: Nishima
authors.identifier: http://orcid.org/0000-0001-8691-1072
authors.initials: N
authors.lastname: Wangoo
mesh_terms: D052157:Aptamers, Nucleotide / Q000032:analysis; D003124:Colorimetry / Q000379:methods*; D006046:Gold / Q000737:chemistry; D010575:Pesticides / Q000032:analysis*; D010702:Phorate / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D010575:Pesticides; D010702:Phorate; D006046:Gold
keywords: Bioanalytical methods; Biosensors; Nanoparticles/nanotechnology