Sustainable Copper Electrochemical Stripping onto a Paper-Based Substrate for Clinical Application

Abstract

The electroanalytical field has exploited great advantages in using paper-based substrates, even if the word "paper" might be general. In fact, the mainly adopted paper-based substrates are often chromatographic and office ones. They are characterized by the following main features (and drawbacks): chromatographic paper is well-established for storing reagents/ treating samples, but the sensitivity compared to traditional screen-printed ones is lower (due to porosity), while office paper represents a sustainable alternative to plastic (with similar sensitivity), but its porosity is not enough to load reagents. To overcome the limitations that might arise due to the adoption of a type of individual paper-based substrate, herein, we describe for the first time the development of a two-dimensional merged paper-based device for electrochemical copper ion detection in serum. In this work, we report a novel configuration to produce an integrated all-in-one electrochemical device, in which no additional working medium has to be added by the end user and the sensitivity can be tuned by rapid preconcentration on porous paper, with the advantage of making the platform adaptable to real matrix scenarios. The novel architecture has been obtained by combining office paper to screen-print a sustainable and robust electrochemical strip and a chromatographic disk to (1) store the reagents, (2) collect real samples, and (3) preconcentrate the analyte of interest. The novel sensing platform has allowed us to obtain a detection limit for copper ions down to 4 ppb in all the solutions that have been investigated, namely, standard solutions and serum, and a repeatability of ca. 10% has been obtained. Inductively coupled plasma-mass spectrometry measurements confirmed the satisfactory correlation.

Review—An Overview on Recent Progress in Screen-Printed Electroanalytical (Bio)Sensors

“…Electrodes can be manufactured on various types of paper-based substrates such as Whatman filter paper, cellulose paper, conductive papers, office paper etc. 36 Depending on the porosity, the different type of papers can be adopted to provide the analytical system the optimal features like robustness, loading capacity, flexibility, and even combination of different paper-based substrates can be used simultaneously to improve the applicability towards real settings analysis, i.e. preconcentration and interferences decrease.…”

Electrochemical sensing of heavy metals in biological media: A review

“…The damaging implications of heavy metals can be reflected in blood and serum samples [57]. Significant changes in Cu within serum, for instance, can be indicative of pathological disorders, such as Menkes' disease and Wilson's disease [58]. Low levels of blood [Zn 2 + ] are associated with infection and inflammation [59].…”

“…An all-in-one electrochemical device, for example, was developed that combined office paper and chromatographic paper to detect Cu 2 + in serum [58]. Office paper was used for the detection of Cu 2 + while the chromatographic paper removed interferents and preconcentrated the sample of interest [58].…”

“…An all-in-one electrochemical device, for example, was developed that combined office paper and chromatographic paper to detect Cu 2 + in serum [58]. Office paper was used for the detection of Cu 2 + while the chromatographic paper removed interferents and preconcentrated the sample of interest [58]. To examine the electrode's ability to detect Cu2 + , serum samples were spiked with up to 300 μg*L -1 Cu 2 + and a calibration curve was generated which resulted in good linearity (R 2 = 0.994) [58].…”

β-Cyclodextrin/CMK-8-Based Electrochemical Sensor for Sensitive Detection of Cu2+

“…The accumulation of HMIs in the food chain has great potential to harm human health [ 2 , 3 ]. Copper, as a crucial trace element, occupies a significant position in a myriad of physiological functions [ 4 , 5 , 6 ]. However, excessive Cu 2+ might lead to cancer [ 7 ], cardiovascular disorders [ 8 ] and neurodegenerative diseases [ 9 ].…”