title: A novel colorimetric sandwich aptasensor based on an indirect competitive enzyme-free method for ultrasensitive detection of chloramphenicol.
abstract: Analytical methods for detection and quantitation of chloramphenicol in blood serum and foodstuffs arse highly in demand. In this study, a colorimetric sandwich aptamer-based sensor (aptasensor) was fabricated for sensitive and selective detection of chloramphenicol, based on an indirect competitive enzyme-free assay using gold nanoparticles (AuNPs), biotin and streptavidin. The designed aptasensor acquires characteristics of AuNPs, including large surface area and unique optical properties, and strong interaction of biotin with streptavidin. In the absence of chloramphenicol, the sandwich structure of aptasensor forms, leading to the observation of sharp red color. In the presence of target, functionalized AuNPs could not bind to 96-well plates, resulting in a faint red color. The fabricated colorimetric aptasensor exhibited high selectivity toward chloramphenicol with a limit of detection as low as 451 pM. Moreover, the developed colorimetric aptasensor was successfully used to detect chloramphenicol in milk and serum with LODs of 697 and 601 pM, respectively.
authors.affiliation: Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Khalil
authors.initials: K
authors.lastname: Abnous
authors.affiliation: Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; Research Institute of Sciences and New Technology, Mashhad, Iran.
authors.forename: Noor Mohammad
authors.initials: NM
authors.lastname: Danesh
authors.affiliation: Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ramezani
authors.affiliation: Cardiovascular Research Center, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Ahmad Sarreshtehdar
authors.initials: AS
authors.lastname: Emrani
authors.affiliation: Targeted Drug Delivery Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address: taghdisihm@mums.ac.ir.
authors.forename: Seyed Mohammad
authors.initials: SM
authors.lastname: Taghdisi
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D002701:Chloramphenicol / Q000302:isolation & purification*; D003124:Colorimetry / Q000379:methods; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008892:Milk / Q000737:chemistry; D044967:Serum / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D002701:Chloramphenicol; D006046:Gold
keywords: Biotin; Chloramphenicol; Colorimetric aptasensor; Gold nanoparticles; Streptavidin