Fabrication of a Sensitive Cholesterol Biosensor Based on Cobalt‐oxide Nanostructures Electrodeposited onto Glassy Carbon Electrode

Abstract

Electrodeposited cobalt oxide (CoOx) nanomaterials are not only used for immobilization of cholesterol oxidase (ChOx) but also as electron transfer mediator for oxidation of H 2 O 2 generated in the enzymatic reaction. Voltammetry and flow injection analysis (FIA) were used for determination of cholesterol. FIA determination of cholesterol with biosensors yielded a calibration curve with the following characteristics: linear range up to 50 mM, sensitivity of 43.5 nA mM À1 cm À2 and detection limit of 4.2 mM. The apparent Michaelis-Menten constant and the response time of the biosensor are 0.49 mM and 15 s, respectively. This biosensor also exhibits good stability, reproducibility and long life time.

Cholesterol Self-Powered Biosensor

“…Different design strategies have been utilised for the development of electrochemical cholesterol biosensors including oxidation by mediated ChOx [5][6][7][8][9][10] or hydrogen peroxide monitoring by horse radish peroxidase 11,12 or by inorganic catalysts 13 and nanostructures [14][15][16] . Despite of the variety of reported cholesterol electrochemical biosensors 4 , only few of them have been shown to operate in whole blood [17][18][19] .…”

Integrated biosensors for personalized medicine

“…However, there are other interesting molecules to detect for clinical interest. Over the last two decades there have been proposed biosensors for lactate [31], cholesterol [43], glutamate [38], creatinine [21], etc. Biomarkers are another large family of biomolecules arising interest, since they are able to point out if a biological process, a disease, or a response to a therapeutic intervention is in progress.…”

Fabrication of Sensitive Potentiometric Cholesterol Biosensor Based on Co3O4 Interconnected Nanowires

“…The properties of nanostructures are largely depending on their morphology and size of the nanoparticles [15,16], which in turn play an important role for the sensor fabrication and their performance [17][18][19][20][21][22]. Among these several nanomaterials, cobalt oxide (Co3O4) nanostructures, the cobalt (II, III) oxide is a p-type magnetic semiconductor.…”

“…In addition to this, Co3O4 has a high isoelectric point (IEP) value ∼ 8 and it can be little higher when the temperature rises [24] and biocompatibility, since cobalt itself is an essential element for plants and animals (as vitamin B12). The high IEP of Co3O4 makes it a good matrix to immobilize an enzyme such as cholesterol oxidase having low isoelectric point (∼ 4.6) through electrostatic interaction [19]. Co3O4 has been used for various applications including heterogeneous catalysts, solid state sensors and electrochemical based device applications [25][26][27][28][29][30][31].…”