Universal Method Based on Layer-by-Layer Assembly for Aptamer-Based Sensors for Small-Molecule Detection

Abstract

Development of a fast and accurate pesticide analysis system is a challenging task, as a large amount of commonly used pesticide has negative effects on humans' health. Detection of pesticide residues is crucial for food safety management and environmental protection. Aptamers�short single-stranded oligonucleotides (RNA or DNA) selected by aptamer selection method SELEX�can selectively bind to their target pesticide molecules with high affinity. Thus, in the present study, we developed an electrochemical biosensor based on aptamers to detect the commonly used pesticide, glyphosate. Carbon fibers were used as the platform to assemble polyelectrolyte layers with the incorporated aptamers selectively binding with glyphosate molecules for electrochemical detection. The best limit of detection of 0.3 μM was achieved at open-circuit potential measurements, which is comparable to the current need in detection of glyphosate. The developed method can be implemented into existing systems for the determination of pesticides on farms to control residual concentrations of glyphosate in soil and water.

Tailoring Defects in B, N-Codoped Carbon Nanowalls for Direct Electrochemical Oxidation of Glyphosate and its Metabolites

“…plays a crucial role in determining the catalyst activity since the electrochemical reactions are most likely to occur at the defective sites. 9,11 Rapid detection of glyphosate (GLY) can be achieved indirectly by aptamer-based sensors with a limit of detection (LOD) of 0.3 μM 12 or by a variety of molecularly imprinted polymers that have been developed; 13 however, direct detection is challenging. In their zwitterionic form, the chemical groups within the GLY molecule are unable to undergo reduction or oxidation at low potentials.…”

Target-Induced Electrochemical Sensor Based on Foldable Aptamer and MoS2@MWCNTs–PEI for Enhanced Detection of AFB1 in Peanuts

“…Nevertheless, the poor portability, relatively high cost, and demand for a skilled operator have limited their applications for portable analysis. Electrochemistry has been widely used in various fields, due to their high selectivity and sensitivity, high signal-to-noise ratio, simplicity, miniaturization, low cost, robust analysis of liquid samples, and high feasibility for on-site application. − Moreover, electrochemical biosensors combine the high sensitivity of electrochemical conversion devices and the high selectivity of biometric systems for the quantitative and qualitative detection of substances . Aptamers are widely used in various biomolecular detection due to their affordable price, high specificity, easy modification, and other advantages .…”