Aptasensing of Chloramphenicol in the Presence of Its Analogues: Reaching the Maximum Residue Limit

Abstract

A novel, label-free folding induced aptamerbased electrochemical biosensor for the detection of chloramphenicol (CAP) in the presence of its analogues has been developed. CAP is a broad-spectrum antibiotic that has lost its favor due to its serious adverse toxic effects on human health. Aptamers are artificial nucleic acid ligands (ssDNA or RNA) able to specifically recognize a target such as CAP. In this article, the aptamers are fixed onto a gold electrode surface by a self-assembly approach. In the presence of CAP, the unfolded ssDNA on the electrode surface changes to a hairpin structure, bringing the target molecules close to the surface and triggering electron transfer. Detection limits were determined to be 1.6 × 10 −9 mol L −1 . In addition, thiamphenicol (TAP) and florfenicol (FF), antibiotics with a structure similar to CAP, did not influence the performance of the aptasensor, suggesting a good selectivity of the CAP-aptasensor. Its simplicity and low detection limit (because of the home-selected aptamers) suggest that the electrochemical aptasensor is suitable for practical use in the detection of CAP in milk samples.

An Electrochemical Impedimetric Aptasensing Platform for Sensitive and Selective Detection of Small Molecules Such as Chloramphenicol

“…It is expected that the repulsion causes a slower interfacial electron-transfer kinetics of the redox probe. In the presence of target molecules, the bulky CAP molecules provide an additional barrier to the electron transfer of the redox species in solution and a further decrease of the peak current [12–14]. …”

“…Pilehvar et al developed an amperometric CAP sensor, based on CAP-specific aptamers, that approaches the MRPL value and that was able to detect CAP in the presence of its analogues [11,12]. Later on, Yan et al developed an amperometric aptasensor for the detection of CAP based on target-induced strand release (TISR).…”

Gold Nanoparticles dotted Reduction Graphene Oxide Nanocomposite Based Electrochemical Aptasensor for Selective, Rapid, Sensitive and Congener-Specific PCB77 Detection

“…4, in the absence of PCB77, the aptamers are believed to remain unfolded and the detection response signal remains low. Upon PCB77 binding, the aptamer is folded into a configuration that forces the ferrocene molecules modified on the aptamer to be in the proximity of the aptamer/Au sensor 22, 23 , and the response signal increases. Sun’s group used Raman and SERS to confirm that the aptamer/Au sensor are more likely to form a hairpin loop 23 .…”

Synthetic biology and biomimetic chemistry as converging technologies fostering a new generation of smart biosensors

“…An electrochemical aptamer-based biosensor for environmental application was also described by Pilehvar et al (2012) for the detection of chloramphenicol. An unfolded ssDNA aptamer was synthesized and immobilized on a gold electrode surface.…”