Electrochemical aptamer sensor for highly sensitive detection of mercury ion with Au/Pt@carbon nanofiber‐modified electrode

Abstract

In this paper, an electrochemical aptamer sensor was proposed for the highly sensitive detection of mercury ion (Hg2+). Carbon nanofiber (CNF) was prepared by electrospinning and high‐temperature carbonization, which was used for the loading of platinum nanoparticles (PtNPs) by the hydrothermal method. The Pt@CNF nanocomposite was modified on the surface of carbon ionic liquid electrode (CILE) to obtain Pt@CNF/CILE, which was further decorated by gold nanoparticles (AuNPs) through electrodeposition to get Au/Pt@CNF/CILE. Self‐assembling of the thiol‐based aptamer was further realized by the formation of Au‐S bond to get an electrochemical aptamer sensor (Aptamer/Au/Pt@CNF/CILE). Due to the specific binding of aptamer probe to Hg2+ with the formation of T‐Hg2+‐T structure, a highly sensitive quantitative detection of Hg2+ could be achieved by recording the changes of current signal after reacting with Hg2+ within the concentration range from 1.0 × 10−15 mol/L to 1.0 × 10−6 mol/L and the detection limit of 3.33 × 10−16 mol/L (3σ). Real water samples were successfully analyzed by this method.

Electrochemical Sensing Based on Nanofibers Modified Electrodes for Application in Diagnostic, Food and Waste Water Samples

“…The stripping current of the proposed sensor increased linearly with Hg 2+ concentration under 15 min accumulation in the range of 5–500 nM with a detection limit of 0.3 nM even in the presence of other heavy metals as interfering factors. To improve the selectivity and sensitivity of the sensing film to Hg 2+ , Xie et al [68b] . used a specific aptamer immobilized on the surface of a nanocomposite of PtNPs loaded on CNF (Figure 9).…”

Potential Applications of Electrospun Nanofibers in Agriculture

“…The nanofibers in some sensors aid in the amplification of signals generated by the presence of the mercury ions given by the binding of Hg 2+ ions with thymine bases of DNA and methylene blue (Ehzari et al, 2019). These sensors also showed sensitivity, stability and reliability in both the test and real samples (Teodoro et al, 2019) (Xie et al, 2021). Besides the Hg 2+ ions, other reported detections include those of Cd 2+ (Liu et al, 2020), Pb 2+ (Oliveira et al, 2020), As 3+ (Tang et al, 2020), Fe 3+ (Zhang et al, 2019) and Cu 2+ which also showed aforementioned properties.…”

Electrospun Nanofibers for Sensing and Biosensing Applications—A Review

“…Another aptamer sensor for mercury ions detection was developed by Xie et al [78]. Carbon ionic liquid electrode was functionalized with platinum nanoparticles (PtNPs)/CNF and AuNPs.…”