Flexible liquid crystal polymer-based electrochemical sensor for in-situ detection of zinc(II) in seawater

Abstract

The authors describe a liquid crystal polymer (LCP) based bismuth (Bi) film electrode that can be directly deployed for in-situ determination of zinc(II) ions. The use of an LCP warrants improved operational reliability, high durability and flexibility of the sensor, allowing it to be mounted on any flat or shaped surface. Square wave anodic stripping voltammetry shows the sensor to be able to detect Zn(II) (-1.64 V vs. thin-film Ag/AgCl reference electrode) in concentrations as low as 1.22 nM at a deposition time of 180 s. Other figures of merit include (a) an analytical sensitivity of 1.55 nA•nM-1 •mm-2 , (b) a linear detection range extending from 4.59 to 1071 nM, (c) a repeatability with a relative standard deviation of 3.35% (for n = 10), (d) a reproducibility with a relative standard deviation of 1.64% (for n = 6). Real-time applicability of the sensor for in-situ detection was demonstrated by determination of Zn(II) in seawater. In an extension of the method, a flexible sensor array consisting of four LCP-based sensors was attached to the hull of an autonomous kayak, which was remotely operated. The response of the sensor array indicated a clear trace of Zn(II) concentrations in seawater. This was confirmed by ICP-MS analysis. The results suggest the potential usage of the flexible LCP electrochemical sensor for in-situ monitoring.

PVDF Nanofiber Sensor for Vibration Measurement in a String

“…LCP is chosen as the substrate since it can be of low thickness, lightweight and highly bendable [46,47]. It has good chemical resistance and hence can maintain its properties in harsh environments [48,49,50]. It also has good mechanical robustness and can take large impact force [50].…”

Development of a Heavy Metal Sensing Boat for Automatic Analysis in Natural Waters Utilizing Anodic Stripping Voltammetry

“… 16 − 19 Simultaneous detection can be realized with one SPE sensor in the low-cost FSS (cost shown in Tables S1 and S2 ) without the need for photolithography, which may have a future impact in resource-limited regions. 17 − 19 …”

“… 10 − 15 To further decrease the labor errors and cost from on-site HM measurements, several automatic sensing probes based on anodic stripping voltammetry have been reported; however, they still suffer from the low portability caused by the large size and lack of remote operation and automation, requiring humans on deck to control the movements of sensing probes between different testing sites, which induces a high cost especially in large lakes and rivers. 16 − 19 A fully autonomous sensing tool for on-site HM measurements in natural waters has rarely been reported.…”

Nanoparticles-Modified Chemical Sensor Fabricated on a Flexible Polymer Substrate for Cadmium(II) Detection

“…Hence, the development of chemical sensors on flexible and stretchable substrates is of great interest to both academic and industrial researchers. Liquid crystal polymers (LCPs), a type of thermoplastic polymers offering a high degree of structural flexibility and mechanical durability [15], are promising substrate materials. In addition, LCPs are capable of withstanding attacks from most aggressive acids, bases, and halogenated hydrocarbons [16].…”