title: Ultrasensitive aptamer biosensor for malathion detection based on cationic polymer and gold nanoparticles.
abstract: In this work, we have demonstrated a novel sensing strategy for an organophosphorus pesticide namely, malathion, employing unmodified gold nanoparticles, aptamer and a positively charged, water-soluble polyelectrolyte Polydiallyldimethylammonium chloride (PDDA). The PDDA when associated with the aptamer prevents the aggregation of the gold-nanoparticles while no such inhibition is observed when the aptamer specific pesticide is added to the solution, thereby changing the color of the solution from red to blue. This type of biosensor is quite simple and straightforward and can be completed in a few minutes without the need of any expensive equipment or trained personnel. The proposed method was linear in the concentration range of 0.5-1000pM with 0.06pM as the limit of detection. Moreover, the proposed assay selectively recognized malathion in the presence of other interfering substances and thus, can be applied to real samples for the rapid screening of malathion.
authors.affiliation: Department of Chemistry & Centre of 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 & Centre of Advanced Studies in Chemistry, Panjab University, Sector-14, Chandigarh 160014, India.
authors.forename: Munish
authors.initials: M
authors.lastname: Kumar
authors.affiliation: Centre for Nanoscience and Nanotechnology (U.I.E.A.S.T), Panjab University, Chandigarh 160014, India.
authors.forename: Kavita
authors.initials: K
authors.lastname: Bansal
authors.affiliation: Department of Chemistry & Centre of Advanced Studies in Chemistry, Panjab University, Sector-14, Chandigarh 160014, India. Electronic address: rohitksg@pu.ac.in.
authors.forename: Rohit K
authors.initials: RK
authors.lastname: Sharma
authors.affiliation: Department of Applied Sciences, University Institute of Engineering & Technology (U.I.E.T.), Panjab University, Sector-25, Chandigarh 160014, India; Centre for Nanoscience and Nanotechnology (U.I.E.A.S.T), Panjab University, Chandigarh 160014, India. Electronic address: nishima@pu.ac.in.
authors.forename: Nishima
authors.initials: N
authors.lastname: Wangoo
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002412:Cations / Q000737:chemistry; D003124:Colorimetry / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis; D005504:Food Analysis / Q000379:methods; D005638:Fruit / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D007306:Insecticides / Q000032:analysis*; D060106:Lakes / Q000032:analysis; D057230:Limit of Detection; D008294:Malathion / Q000032:analysis*; D027845:Malus / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011095:Polyethylenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D052157:Aptamers, Nucleotide; D002412:Cations; D004785:Environmental Pollutants; D007306:Insecticides; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D006046:Gold; D008294:Malathion
keywords: Aptasensor; Colorimetric detection; Gold nanoparticles; Malathion