Rapid Detection of Staphylococcus aureus Using Paper-Derived Electrochemical Biosensors

Abstract

Several groups have recently explored the idea of developing electrochemical paper-based wearable devices, specifically targeting metabolites in sweat. While these sensors have the potential to provide a breadth of analytical information, there are several key challenges to address before these sensors can be widely adopted for clinical interventions. Toward this goal, we describe the development of a paper-based electrochemical sensor for the detection of Staphylococcus aureus. Enabling the application, this report describes the use of paper-derived carbon electrodes, which were modified with a thin layer of sputtered gold (that minimizes lateral resistivity and significantly improves the electron transfer process) and with chitosan (used as a binder, to offer flexibility). The resulting material was laser-patterned and applied for the development of an electrochemical biosensor controlled (via a wireless connection) by a custom-built, portable potentiostat. As no interference was observed when exposed to other bacteria or common metabolites, this wearable system (paper-derived electrodes + potentiostat) has the potential to detect the presence of S. aureus in the skin, a commonly misdiagnosed and mistreated infection.

Lab-on-a-Drone: remote voltammetric analysis of lead in water with real-time data transmission

“…Due to its higher sensitivity, only the data collected via SWASV were used for quantitative purposes. 6,7 However, to show the advantages of the Lab-on-a-Drone over recent publications, 38 its high versatility, and functionally, it was able to perform the CV and DPASV. 7 Thus, the CV was used to check the BDD performance and DPASV was developed due to being widely used in electroanalytical analysis.…”

Scalable and green formation of graphitic nanolayers produces highly conductive pyrolyzed paper toward sensitive electrochemical sensors

“…31 Here, the annealing steps were performed at room pressure, hence not reaching the supercritical conditions for isopropanol (235 °C and 4.8 MPa). Nonetheless, although a boosted graphitization level would likely be obtained by supercritical isopropanol because of favorable physical properties such as extremely low viscosity and high diffusivity, 12 the graphitization of the PP surfaces is expected to be triggered at some level by the nonsupercritical isopropanol, as it was observed by XPS. Specifically, PP I10 8 and PP I10 10 showed a reduced amount of carbonyl groups, CvO (see Fig.…”

“…The brittleness hurdle can be solved by the addition of carbon nanotubes, 8 partial permeation of soft polymers within the PP pores, [9][10][11] and use of chitosan as a binder. 12 Regarding the hydrophobicity issue, oxidation of the PP substrate in air plasma, 13 pre-wetting the electrode with an alcohol, 10 and coating with hydrophilic 9 or amphiphilic 11 nanolayers are efficient strategies to improve the PP wettability by aqueous solutions. These coatings can also enable the gradual flow of samples through PP pores 10 and provide the antibiofouling ability, 11 leveraging low-hindrance charge transfer reactions across the entire paper thickness and then allowing sensitive and accurate analyses even in complex samples.…”

“…15,16 Another recently published strategy is the sputtering of a thin layer of Au on the backside of the sensor, which is intended to decrease the overall resistivity of the substrate by diminishing the lateral resistivity between the electrical contacts and the detection area of the electrode. 12 Although valuable by demonstrating the potential of PP in developing ePADs, these methods need precursor solutions or costly equipment that may imply an increase in the cost and toxicity of the electrodes. Furthermore, the least resistivities (e.g., 370 15 and 250 mΩ cm) 16 that can be achieved by these approaches are 1000 times higher than the values of pure metals (e.g., ∼0.2 mΩ cm for Au and Ag).…”

Advancements and future directions in cardiac biomarker detection using lateral flow assays

“…The enzymatic conversion of OPD to diamine produced a cathodic redox signal, which is detected through cyclic voltammetry in an electrochemical workstation, which could be adapted to a portable system. 81 A signal improvement was observed when antigen binding occurs, resulting in an LOD of 0.15 ng mL −1 and a dynamic concentration range from 100 to 700 ng mL −1 .…”