A fluorescent aptasensor based on a DNA pyramid nanostructure for ultrasensitive detection of ochratoxin A.
Analytical techniques for detection of ochratoxin A (OTA) in food products and blood serum are of great significance. In this study, a fluorescent aptasensor was developed for sensitive and specific detection of OTA, based on a DNA pyramid nanostructure (DPN) and PicoGreen (PG) dye. The designed aptasensor inherits characteristics of DPN, such as high stability and capacity for PG loading. PG, as a fluorescent dye, could bind to double-stranded DNA (dsDNA). In the absence of OTA, the pyramid structure of DPN remains intact, leading to a very strong fluorescence emission. Because of higher affinity of aptamer for its target relative to its complementary strand, upon addition of target, the pyramid structure of DPN is disassembled, leading to a weak fluorescence emission. The presented aptasensor showed high specificity toward OTA with a limit of detection (LOD) as low as 0.135 nM. Besides, the designed sensing strategy was successfully utilized to recognize OTA in serum and grape juice with LODs of 0.184 and 0.149 nM, respectively.
School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Razavi Khorasan, Iran.
Morteza Alinezhad
MA
Nameghi
Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Razavi Khorasan, Iran.|Research Institute of Sciences and New Technology, Mashhad, Razavi Khorasan, Iran.
Noor Mohammad
NM
Danesh
Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Razavi Khorasan, Iran.
Mohammad
M
Ramezani
School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Razavi Khorasan, Iran.
Faezeh Vahdati
FV
Hassani
Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Razavi Khorasan, Iran. abnouskh@mums.ac.ir.
Khalil
K
Abnous
Targeted Drug Delivery Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Razavi Khorasan, Iran. taghdisihm@mums.ac.ir.
Seyed Mohammad
SM
Taghdisi
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002273:Carcinogens / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry*; D005504:Food Analysis / Q000379:methods; D000067030:Fruit and Vegetable Juices / Q000032:analysis; D006801:Humans; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry*; D009793:Ochratoxins / Q000032:analysis* / Q000097:blood
D052157:Aptamers, Nucleotide; D002273:Carcinogens; D005456:Fluorescent Dyes; D009793:Ochratoxins; C025589:ochratoxin A
DNA pyramid nanostructure; Fluorescent aptasensor; Ochratoxin A; PicoGreen