Non-invasive wearable electrochemical sensors: a review

Recent advances in cortisol sensing technologies for point-of-care application.

This paper describes the design and characterization of an open-source “universal wireless electrochemical detector” (UWED). This detector interfaces with a smartphone (or a tablet) using “Bluetooth Low Energy” protocol; the smartphone provides (i) a user interface for receiving the experimental parameters from the user and visualizing the result in real time, and (ii) a proxy for storing, processing, and transmitting the data and experimental protocols. This approach simplifies the design, and decreases both the size and the cost of the hardware; it also makes the UWED adaptable to different types of analyses by simple modification of the software. The UWED can perform the most common electroanalytical techniques of potentiometry, chronoamperometry, cyclic voltammetry, and square wave voltammetry, with results closely comparable to benchtop commercial potentiostats. Although the operating ranges of electrical current and voltage of the UWED (±1.5 V, ±180 μA) are more limited than most benchtop commercial...

Open-Source Potentiostat for Wireless Electrochemical Detection with Smartphones

Recent advances in lab-on-a-chip for biosensing applications

Point-of-care (POC) diagnostic devices have been predicted to provide a boon in health care especially in the diagnosis and detection of diseases. POC devices have been found to have many advantages like a rapid and precise response, portability, low cost, and non-requirement of specialized equipment. The major objective of a POC diagnostic research is to develop a chip-based, self-containing miniaturized device that can be used to examine different analytes in complex samples. Further, the integration of microfluidics (MF) with advanced biosensor technologies is likely to result in improved POC diagnostics. This paper presents the overview of the different materials (glass, silicon, polymer, paper) and techniques for the fabrication of MF based POC devices along with their wide range of biosensor applications. Besides this, the authors have presented in brief the challenges that MF is currently facing along with possible solutions that may result in the availability of the accessible, reliable, and cost-efficient technology. The development of these devices requires the combination of developed MF components into POC devices that are user-friendly, sensitive, stable, accurate, low cost, and minimally invasive. These MF based POC devices have tremendous potential in providing improved healthcare including easy monitoring, early detection of disease, and increased personalization.

Microfluidics Based Point-of-Care Diagnostics

A low-cost miniaturized potentiostat for point-of-care diagnosis

This paper presents a fully automated low temperature co-fired ceramic (LTCC) based microfluidic system with an integrated electrochemical biosensing platform for the detection of cortisol. This paper presents the design, fabrication, integration and testing of the integrated 3D microfluidic system. The electrochemical immunosensor consists of microfabricated interdigitated Au electrodes, onto which cortisol antibodies are immobilized using a self-assembled monolayer (SAM) matrix of dithiobis(succinimidyl propionate) (DTSP). Finite element based simulation was used to optimize the fluid flow dynamics and washing efficiency required for immunosensing in the LTCC microfluidic assay chamber. Cortisol was used as a model analyte to demonstrate electrochemical immunosensing in a fully automated microfluidic system. Cortisol was detected in a linear range of 10 pM–100 nM at a sensitivity of 0.207 μA/M using cyclic voltammetry (CV). This system establishes the basis for the development of a POC cortisol sensor.

Nicolas Norena

Papers

A low-cost miniaturized potentiostat for point-of-care diagnosis

An LTCC-based microfluidic system for label-free, electrochemical detection of cortisol