Efficient Point-of-Care Detection of Uric Acid in the Human Blood Sample with an Enhanced Electrocatalytic Response Using Nanocomposites of Cobalt and Mixed-Valent Molybdenum Sulfide.

This work efficiently detects uric acid (UA) in a human blood sample using cobalt nanoparticle-immobilized mixed-valent molybdenum sulfide on the copper substrate in a point-of-care (PoC) device. The sensor electrode was fabricated by micromachining of Cu clad boards employing an engraver to generate a three-electrode system consisting of working electrode (WE), reference electrode (RE), and counter electrode (CE). The WE was subjected to physical vapor deposition of mixed-valent MoS layers by a reaction between Mo(CO) and HS at ∼200 °C using a simple setup following which CoNPs were electrochemically deposited.

3-D printed electrode integrated sensing chip and a PoC device for enzyme free electrochemical detection of blood urea.

Herein we report a novel electrochemical sensing chip and a point-of-care device (PoC) for enzyme-free electrochemical detection of urea in human blood. The electrochemical sensing chip was developed by 3-D printing of conductive Ag ink and subsequent electrodeposition of AuNP-rGO nanocomposite. Material characterization of the sensing chip was conducted to find a plausible mechanism for the electrochemical reaction with urea.

Printed oxygen gas sensor using copper-DTDTPA solid electrolyte.

We present a new method for the rapid and cost-effective fabrication of solid electrolyte-based printed potentiometric oxygen sensors working at ambient temperature using Cu-dithiolated diethylene triamine pentaacetic acid complex molecules (Cu-DTDTPA) adsorbed on Grade-1 laboratory filter paper and subsequent 3-D printing of interdigitated electrodes employing silver/silver chloride ink. The decrease in conductivity with time and frequency-dependent impedance response confirms the filter paper adsorbed Cu-DTDTPA as a solid electrolyte. A plausible structure of the Cu-DTDTPA solid electrolyte and its mechanism of reaction with oxygen are presented.

A paper based self-pumping and self-breathing fuel cell using pencil stroked graphite electrodes.

We develop a paper based fuel cell in which fluids flow through a capillary transport mechanism. The pencil stroked graphite electrodes take oxygen from quiescent air. This simple and efficient paper fuel cell can generate energy to the tune of 32 mW cm(-2) over a prolonged duration of around 1000 minutes, and with the consumption of a very low volume of formic acid as fuel (~1 mL).