Papers by Keyword: Amperometric

Abstract: Point-of-care diagnostic systems face challenges because they are mainly designed for laboratory settings. Biosensor detection plays a crucial role in modern healthcare by enabling real-time monitoring of biomolecules, facilitating rapid diagnosis, and allowing for timely interventions. These sensors are vital for various applications, including glucose monitoring, infectious disease detection, and environmental analysis. The reader-disposable approach is gaining popularity in both research and commercial point-of-care devices. Open-source hardware projects based on microcontrollers are increasingly favored for biosensing applications due to their cost-effectiveness and flexibility. However, biosensors that operate in the nanoampere range still encounter issues with power supply, signal amplification, and result display. This research focuses on designing and developing a portable amperometric device for low-current detection. The system includes a multi-stage circuit featuring a voltage converter, voltage amplifier, microcontroller, display, and power supply. A shunt resistor converts input current to voltage, with an op-amp MAX4238 IC amplifying the voltage at a gain of 100. A NodeMCU microcontroller reads the output voltage and displays it on an LCD. For simulation, LTspice, Proteus 8 Pro, and Arduino software are used. Experimental testing involves using a voltage source and variable resistor to verify accuracy, comparing theoretical, simulation, and experimental results. The system demonstrated a sensitivity down to approximately 45 nA, with output linearity maintained across the tested range. The average error margin between experimental and theoretical values remained within ±2.5%. This advancement improves sensitivity in detecting low currents, enhancing point-of-care biosensing applications.

Abstract: Electrodes have an important role in performance of sulfite detector biosensors. To increase efficiency of performance, using immobilizing processes in the structure of an enzyme electrode is very important. Enzymes can be connected to the working electrode by crosslinking and trapping methods. In this paper, sulfite oxidase enzyme has immobilized on aluminum, screen-printed carbon and glassy carbon electrodes in different ways. Flow production measurement of amperometric cycle showed that aluminum and screen-printed carbon electrode had better performance at concentrations less than 110 micro-molar, but in higher concentrations, glassy carbon electrode showed highest conductivity.

Abstract: The purpose of this study was to develop the anodized titanium oxide nanotubes (ATONs) as a pH electrode with amperometric and potentiometric method. Titanium oxide nanotubes film was produced on pure titanium piece by titanium anodization at room temperature. The best one ATONs electrode has a linear pH response approximately 53 mV/pH with potentiometric method and 13 A/pH with amperometric method in the concentration range between pH 2 and 12.