Results
Title

A fluorescent aptasensor based on a DNA pyramid nanostructure for ultrasensitive detection of ochratoxin A.

Authors

Nameghi, Morteza; Danesh, Noor; Ramezani, Mohammad; Hassani, Faezeh; Abnous, Khalil; Taghdisi, Seyed

Abstract

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.

Subjects

OCHRATOXINS; MYCOTOXINS; SERUM; NANOSTRUCTURES; MICROBIAL toxins

Publication

Analytical & Bioanalytical Chemistry, 2016, Vol 408, Issue 21, p5811

ISSN

1618-2642

Publication type

Academic Journal

DOI

10.1007/s00216-016-9693-7