Pb(II) Determination in a Single Drop Using a Modified Screen-Printed Electrode

Abstract

This work presents the development and validation of an electroanalytical method for Pb(II) determination in a single drop. The electrochemical sensors used were an unmodified screen-printed electrode (SPE) and a Bi-film SPE (BiFSPE). Anodic square wave stripping voltammetry (SWASV) was performed at an accumulation potential of −1.5 V vs. Ag/AgCl and an accumulation time of 60 s. Electroanalysis with an unmodified SPE did not yield satisfactory results, whereas the BiFSPE was a much better analysis method. The linear concentration using the BiFSPE was in the range of 138.8–162.5 µg/L. The accuracy and precision were evaluated for different spiked concentrations, but the method using the unmodified SPE was neither accurate nor precise. Using the BiFSPE, the method was found to be both accurate and precise for Pb(II) determination at a concentration of 140.0 μg/L, with recovery and relative standard deviation (RSD) of 106.6% and 12.1%, respectively. In addition, using the BiFSPE, LOD and LOQ values of 1.2 μg/L and 3.3 μg/L were obtained, respectively. The possible interference effect on Pb(II) stripping signal was checked in the presence of Cd(II), Zn(II), Cu(II), Sn(IV), Sb(III), Hg(II), Fe(III), As(V), K(I), I−, Ca(II), and NO3−. Electrochemical impedance spectroscopy measurements were also performed for the unmodified SPE and BiFSPE. The application of single drop Pb(II) analysis was tested by real water sample analysis.

Electrochemical Determination of Kynurenine Pathway Metabolites—Challenges and Perspectives

“…In general, chromatography-based approaches require lower amounts of sample for analysis. However, electroanalysis coupled with screen-printed electrodes allows for conducting an analysis using a single drop of the sample [100] and shows a great opportunity for miniaturization and the construction of all-in-one devices [101].…”

The development of an electropolymerized, molecularly imprinted polymer (MIP) sensor for insulin determination using single-drop analysis

“…3,[34][35][36][37][38] Due to their low cost, availability, portability, ease of fabrication, and commercial availability, screen-printed electrodes (SPEs) can be used for the rapid and sensitive electroanalysis of many target analytes. [34][35][36][37] Moreover, their application for on-site analysis is further advanced by their modification with different materials and flexibility. 36,37 Three electrode systems (a working electrode, WE; a reference electrode, RE; and a counter electrode, CE) were identified as potential candidates for a point-of-care (POC) device design and applications in environmental and clinical analysis.…”

“…36 As such, they are highly suitable for working with microvolumes and decentralized assays, such as a singledrop analysis. [35][36][37]39 Although the latter simplifies on-site analysis, since no electrochemical cell or stirrer is required, there are only a few publications on this subject. 3,34,35,37,[40][41][42][43] But, for example, a smartphone-based cyclic voltammetry (CV) platform was designed as a portable system for single-drop determination of glucose.…”

“…22 Electrode systems based on established screen-printing technology have challenged the use of conventional solid electrodes to quantify various compounds. 3,[34][35][36][37][38] Due to their low cost, availability, portability, ease of fabrication, and commercial availability, screen-printed electrodes (SPEs) can be used for the rapid and sensitive electroanalysis of many target analytes. [34][35][36][37] Moreover, their application for on-site analysis is further advanced by their modification with different materials and flexibility.…”

“…[35][36][37]39 Although the latter simplifies on-site analysis, since no electrochemical cell or stirrer is required, there are only a few publications on this subject. 3,34,35,37,[40][41][42][43] But, for example, a smartphone-based cyclic voltammetry (CV) platform was designed as a portable system for single-drop determination of glucose. 44 In another study, a similar smartphonebased sensory system using square-wave voltammetry (SWV) and a graphene SPE was constructed to detect norepinephrine in a sample drop.…”