Paper‐based Electrochemical Devices Coupled to External Graphene‐Cu Nanoparticles Modified Solid Electrode through Meniscus Configuration and their Use in Biological Analysis

Abstract

This paper demonstrates, for the first time, the use of paper‐based electrochemical devices coupled to external solid working electrodes. The paper‐based electrochemical cells were fabricated using inexpensive and largely available office paper, according to a simple protocol that consists on the creation of hydrophobic barriers using paraffinized paper and preheated metal stamp. The counter and reference electrodes were integrated to the paper platform through the deposition of carbon and silver inks, respectively. The electrochemical paper analytical device (ePAD) was coupled to external glassy carbon rod electrode modified with reduced graphene oxide doped with Cu nanoparticles through meniscus configuration. The analytical usefulness of this electrochemical approach was demonstrated through the simultaneous determination of paracetamol and caffeine in biological samples. The analytes were successfully quantified in real urine samples and limits of detection of 24.6 nM (paracetamol) and 36.1 nM (caffeine) were obtained. The paper platform showed good stability (RSD of 1.07 % for the peak currents and 1.43 % for the peak potentials) and satisfactory performance. The use of solid electrodes coupled to paper electrochemical devices, firstly demonstrated here, opens new possibilities for the utilization of ePADs in electrochemistry and electroanalytical chemistry and offers advantages such as the extremely reduced consumption of reagents and the minimal generation of wastes.

Electrochemical detection based on nanomaterials in CE and microfluidic systems

“…LODs ranged from 0.5–2.5 μM. There is another work in which an ePAD sensor is developed for paracetamol and caffeine determination in urine samples using DPV . The originality of this paper relies on the fact that the working electrode is not integrated in the ePAD.…”

Lab-on-Paper Devices for Diagnosis of Human Diseases Using Urine Samples—A Review

“…Studies have shown that the detection performance of colorimetric methods can be improved by inducing the aggregation of nanomaterials in order to enhance the detection resolution [119,149,156]. Similarly, in the EC and SERS methods, the detection performance can be improved by patterning nanomaterials with good electrical conductivity on the electrode surface [120,125,135,166,167]. In CL and fluorescence methods, the intensity of the detection signal can be amplified through the catalytic reaction of nanomaterials and the induced fluorescence quenching [132,[168][169][170], respectively.…”

“…Moreover, "prohibited drugs" are psychotropic or narcotic drugs that are used for recreational "non-medical purposes" and may cause dependency and eventual addiction. Many lab-on-paper platforms have been proposed for the detection of drugs such as caffeine, paracetamol, adenosine, cocaine, ketamine, cannabidiol (CBD), methamphetamine (MA), 3,4-methylenedioxy -N-methamphetamine (MDMA) and tricyclic antidepressants [135][136][137][138][139][140][141][142]. Petroni et al [135] demonstrated a lab-on-paper platform with a CE sensor coupled to an external graphene-Cu nanoparticlemodified solid electrode through a meniscus configuration for the detection of paracetamol and caffeine in urine samples.…”

“…Many lab-on-paper platforms have been proposed for the detection of drugs such as caffeine, paracetamol, adenosine, cocaine, ketamine, cannabidiol (CBD), methamphetamine (MA), 3,4-methylenedioxy -N-methamphetamine (MDMA) and tricyclic antidepressants [135][136][137][138][139][140][141][142]. Petroni et al [135] demonstrated a lab-on-paper platform with a CE sensor coupled to an external graphene-Cu nanoparticlemodified solid electrode through a meniscus configuration for the detection of paracetamol and caffeine in urine samples. The working electrode had the form of a glassy carbon electrode consisting of graphene oxide-copper nanoparticles (GO-CuNPs) synthesized via the chemical reduction of GO and Cu(II) salt.…”

Graphene Oxide: A Smart (Starting) Material for Natural Methylxanthines Adsorption and Detection

“…The sensor was effective for the simultaneous detection of these analytes, with a detection limit for caffeine of 5.5 × 10 −8 mol L −1 . Lucca and coworkers [62] reported the first example of a paper-based electrochemical sensor for the simultaneous detection of caffeine and paracetamol in real biological samples. In particular, a chemically treated office paper coupled with two electrodes acted as an “electrochemical paper analytical device (ePAD)”, which allowed the reduction of the analyzed volume to the order of μL.…”