Embedded Au Nanoparticles-Based Ratiometric Electrochemical Sensing Strategy for Sensitive and Reliable Detection of Copper Ions

Abstract

The ratiometric method allows the measurement of ratio changes between two signals, which can reduce the detection signal fluctuations caused by distinct background conditions and greatly improve the reproducibility and reliability of detection. However, in contrast with the emerging dual excitation or dual emission dyes applied in ratiometric luminescence measurement, only a few internal reference probes have been exploited for ratiometric electrochemical detection. In this paper, a gold nanoparticles@carbonized resin nanospheres composite with thermally reduced graphene oxide as scaffold (AuNPs@CRS-TrGNO) has been fabricated, and the AuNPs embedded in the CRS were first used as an internal reference probe for ratiometric electrochemical detection. The detachment and aggregation of AuNPs is suppressed by embedding in the CRS, so its redox signal is very stable, which provides feasibility for ratiometric detection. Moreover, the embedment of AuNPs, carbonization of resin spheres, and hybridization with TrGNO all have played positive roles in improving the charge transfer rate, which leads to excellent electrochemical performance of the composite. Based on these characteristics of the AuNPs@CRS-TrGNO, a new ratiometric electrochemical detection platform was constructed, and copper ions (Cu 2+ ) in simulated seawater were successfully detected. This ratiometric method has the advantages of simple design and convenient operation, and obviously it improves the reproducibility and reliability of the electrochemical sensor.

Ratiometric Electrochemistry: Improving the Robustness, Reproducibility and Reliability of Biosensors

“…Therefore, several strategies have been explored to improve their long-term stability, repeatability, and reproducibility. Luo and Yang embedded AuNP into a carbonised resin as an internal reference for the detection of Cu 2+ (Figure 29) [97]. 15 measurements were conducted over five days, with 92% of the original signal maintained.…”

Ratiometric electrochemical detection of tryptophan based on ferrocene and carboxylated-pillar[6]arene hybrid metal–organic layers

“…To solve this problem, ratiometric electrochemical sensing has been developed for stable and accurate measurement. 8,9 A multifunctional electrode material is highly preferred to construct ratiometric electrochemical sensors.…”

Simultaneous Visual Detection and Removal of Cu2+ with Electrospun Self-Supporting Flexible Amidated Polyacrylonitrile/Branched Polyethyleneimine Nanofiber Membranes

“…To date, different methods have been used for detecting Cu 2+ , such as atomic absorption spectrometry, inductively coupled plasma mass spectrometry, electrochemistry, colorimetry, and fluorescence. − Among them, colorimetry has been widely considered because it exhibits rapidity, simple operation, easy observation, and portability . In parallel with the development of the detection methods, many technologies have been reported for Cu 2+ removal, for instance, chemical precipitation, ion exchange, and membrane filtration. − Adsorption has wide-ranging applications in the removal of Cu 2+ by virtue of outstanding features, for example, simplicity, high efficiency, and low cost …”