Self-Assembled MoS2/ssDNA Nanostructures for the Capacitive Aptasensing of Acetamiprid Insecticide

Abstract

The aim of this work is to detect acetamiprid using electrochemical capacitance spectroscopy, which is widely used as a pesticide in agriculture and is harmful to humans. We have designed aptasensing platform based on the adsorption of a DNA aptamer on lipoic acid-modified MoS2 nano-sheets. The biosensor takes advantage of the high affinity of single-stranded DNA sequences to MoS2 nano-sheets. The stability of DNA on MoS2 nano-sheets is assured by covalent attachment to lipoic acid that forms self-assembled layer on MoS2 surface. The biosensor exhibits excellent capacitance performances owing to its large effective surface area making it interesting material for capacitive transduction system. The impedance-derived capacitance varies with the increasing concentrations of acetamiprid that can be attributed to the aptamer desorption from the MoS2 nanosheets facilitating ion diffusion into MoS2 interlayers. The developed device showed high analytical performances for acetamiprid detection on electrochemical impedance spectroscopy EIS- derived capacitance variation and high selectivity toward the target in presence of other pesticides. Real sample analysis of food stuff such as tomatoes is demonstrated which open the way to their use for monitoring of food contaminants by tailoring the aptamer.

In-silico selection of peptides for the recognition of imidacloprid

“…WQA34) by comparing it with two other pesticides. The first one is acetamiprid (ACE) [ 30 ] and the second one is clothianidin (CLT) [ 7 , 9 ], which are two widely used neonicotinoid insecticides from the same family Fig 4A [ 9 , 30 ]. As shown in Fig 4B , The MM-PBSA results of IMI, ACE and CLT were respectively –5.88±0.38 kcal/mol, –2.00±0.48 kcal/mol and –1.02±0.55 kcal/mol, demonstrating a higher affinity of WQA34 to the target pesticide although there is structural similarity between them.…”

Enhanced sensitivity in electrochemical detection of ochratoxin A within food samples using ferrocene- and aptamer-tethered gold nanoparticles on disposable electrodes

“…Subsequently, the impact of incubation time on the tethering of FcL onto the gold nanoparticle surface was investigated. 47,48 Findings revealed a progressive rise in the current peak associated with ferrocene oxidation as the incubation time increased, reaching a plateau at 120 minutes in a 10 mM FcL solution to form a dense self-assembled layer procuring the highest current densities of the ferrocene oxidation peaks (Fig. 3B).…”

Recent progress of UCNPs–MoS2 nanocomposites as a platform for biological applications

“…5(A)). Hamami et al 55 designed a MoS 2 -ssDNA aptamer sensor based on alpha-lipoic acid modification, which utilized the high specific surface area and semiconductor form of MoS 2 for the determination of acetamiprid in foodstuffs by electrochemical capacitance spectrometry. The sensor exhibited good specificity and high sensitivity for acetamiprid, with a detection limit as low as 14 fM, and has potential to be applied to monitor food contamination in the future.…”