Study on the binding mode of aptamer to ampicillin and its electrochemical response behavior in two different reaction media.

A study was carried out to investigate the binding mode of aptamer to ampicillin (AMP) and its electrochemical response behavior. The binding mode was confirmed using the molecular dynamics (MD) simulation method to obtain the corresponding binding dynamic change process. Following the confirmed binding mode, a qualitative elucidation was provided on the electrochemical response characteristics of a single-probe aptamer-based folding sensor.

Lengthening the aptamer to hybridize with a stem-loop DNA assistant probe for the electrochemical detection of kanamycin with improved sensitivity.

By adding 6 thymines to lengthen the parent aptamer combined with the change of "on" and "off" induced by the target for an assistant stem-loop DNA probe (ASP-SLP-MB), a new folding-type electrochemical kanamycin (Kana) aptamer-engineering dual-probe-based sensor (sensor d) was developed. By purposefully reducing the background current and increasing the electron transfer efficiency of methylene blue (MB), the sensor obtained significantly enhanced detection sensitivity compared with non-aptamer-engineering one-probe-based sensor (sensor a). Such efficacy was validated by a big decrease from 530.

Two kanamycin electrochemical aptamer-based sensors using different signal transduction mechanisms: A comparison of electrochemical behavior and sensing performance.

Two typical kanamycin-A (KAN-A) electrochemical aptamer-based sensors employing different signal transduction mechanisms were deliberately designed and constructed with a similar structure. One sensor (sensor-1) was based on the classical probe conformation changing mode (PCCM) with a methylene blue (MB) label used as an electrochemical tag; the other sensor (sensor-2) used the target-induced signal probe shifting (TISPS) method with a free MB label in the assay solution. The difference in signal transduction mechanisms resulted in big differences in basic electrochemical behavior and comprehensive sensing performance.

Electrochemical aptamer-based sensors for food and water analysis: A review.

Global food and water safety issues have prompted the development of highly sensitive, specific, and fast analytical techniques for food and water analysis. The electrochemical aptamer-based detection platform (E-aptasensor) is one of the more promising detection techniques because of its unique combination of advantages that renders these sensors ideal for detection of a wide range of target analytes. Recent research results have further demonstrated that this technique has potential for real world analysis of food and water contaminants.