Electrochemical aptamer-based sensors

Abstract

The valuable properties of aptamers, such as specificity, sensitivity, stability, cost-effectiveness and design flexibility, have favoured their use as biorecognition elements in biosensor development. These synthetic affinity probes can be developed for almost any target molecule, covering a wide range of applications in fields such as clinical diagnosis and therapy, environmental monitoring and food control. The combination of aptamers with highperformance electrochemical transducers, with their inherent high sensitivities, fast response times and simple equipment, has already provided several electrochemical aptamer-based sensors. Moreover, the small size and versatility of aptamers allow efficient immobilisations in high-density monolayers, an important feature towards miniaturisation and integration of compact electrochemical devices. This review describes the state-of-the-art of electrochemical aptamer-based sensors, entering into the details of the different strategies and types of electrochemical transduction and also considering their advantages when applied to the analysis of complex matrices.

Electrochemical Biosensors in Point‐of‐Care Devices: Recent Advances and Future Trends

“…Aptamers can also be labeled with enzymes such as horseradish peroxidase (HRP), glucose oxidase (GOD) or alkaline phosphatase (AP). [89] In such cases, chemical reactions are performed to add an electroactive group at the other end of the aptamer. However, the use of enzymes can reduce the lifetime of the sensor due to the instability of such biomolecules.…”

Electrochemical Biosensors for Drug Analysis

“…The three-dimensional shape of oligonucleotides allows the detection of a wide range of analytes such as ions, amino acids, organic dyes, antibiotics, vitamins, drugs, peptides, proteins, or even whole cells. Aptasensors are able to discriminate between closely related compounds on the basis of subtle structural differences [158]. A labeled aptasensor has an additional probe (enzyme, redox marker, or nanoparticle) covalently bound to the aptamer or to the target molecule.…”

A G-quadruplex aptamer based impedimetric sensor for free lysine and arginine

“…Coronary artery bypasses, graft surgery and treatment of proliferative diseases are just some of the procedures that currently utilise aptamers 13 . The high selectivity of aptamers derives from their specific 3D structures, which can distinguish between similar compounds with only subtle structural differences 14 . As an example, in a study by Geiger et al 15 , an RNA aptamer had an affinity of 0.33 μM to L-arginine and bound 10 4 times tighter than to its enantiomer, D-arginine.…”