Effect of anions on the morphology of Co3O4 nanostructures grown by hydrothermal method and their pH sensing application

Abstract

Abstract:A fast, reliable, accurate, precise and sensitive pH sensor device is highly demanding for the monitoring of pH in biological, clinical and food industry samples. In this research work, the effect of anions on the morphology of cobalt oxide (Co3O4) nanostructures is investigated using low temperature chemical approach for the growth. Different anions have shown visible effect on the morphology of Co3O4 nanostructures. Scanning electron microscopy, X-ray diffraction and transmission electron microscopy techniques were used for the material characterization.This study has shown highly dense, uniform and good crystal quality of fabricated Co3O4 nanostructures. The nanostructures obtained from the cobalt chloride were used for the development of potentiometric pH sensor electrode. The pH sensor electrode showed excellent linearity and close to Nernstian response for the pH range of 3-13 with a sensitivity of -58.45 mV/pH. Moreover, the proposed sensor showed a fast response time of 53 s, and acceptable reducibility and repeatability. The highly sensitive and a fast time response of the proposed sensor device indicate its potential application for the monitoring of pH from real samples including biological fluids.

Evaluation on the Egfet Ph Sensing Performance of Sol-Gel Spin Coated Titanium Dioxide Thin Film

“…As a result, the pH sensitivity of the sample was found to be at 58.70 mV/pH while its linearity was 0.9922. This value is considered high and also obey the Nernstian theoretical response of 59 mV/pH [19]. In a metal oxide-based pH sensing membrane, another sensing performance evaluation that was usually studied is the hysteresis measurement.…”

Nitrogen‐doped Hollow Co3O4 Nanofibers for both Solid‐state pH Sensing and Improved Non‐enzymatic Glucose Sensing

“… firstly reported the thermal decomposition of aqueous cobalt nitrate to form cobalt oxide, there only have very few reports about using Co 3 O 4 in solid‐state pH detection. The pH sensing mechanism of cobalt oxide typically involves in protonation or deprotonation at the interface of solid‐state of nanostructure . Further more, to address the applicability of the as‐synthesized Nafion/NH−Co 3 O 4 NFs/GCE as a solid‐state pH sensor, pH titration was carried out from pH 3.0 to pH 9.0 and in reverse titration direction (pH 9.0 to pH 3.0), as well as pH 9.0 to pH 13.0 and vice versa.…”

PHAIR – A biosensor for pH measurement in air-liquid interface

“…Among these methods, electrochemical-based pH sensors have great potential to be miniaturized and integrated into a cell culture system, especially potentiometric sensors. It is well-known that various metal oxides such as copper oxide 36 , iridium oxide 5,[37][38][39][40] , tungsten oxide [41][42][43][44] , cobalt oxide 45 , titanium oxide 45 , ruthenium oxide 39 , zinc oxide 46 , indium tin oxide [47][48][49] , and palladium oxide [50][51][52][53] can be used as a pH sensing material in a potentiometric sensor. The fabrication of this type of pH sensor can be simplified to develop a straightforward compact pH sensor that can be easily integrated into different cell culture systems.…”