Biosensing of Cholesterol and Glucose Facilitated by Cationic Polymer Overlayers on Ni(OH)₂/NiOOH at Physiological pH

Abstract

The electrocatalytic properties of the redox couple Ni(OH) 2 /NiOOH at physiological pH was investigated in the presence of cationic polymeric films providing alkaline microenvironments, with the objective of developing a biosensor for cholesterol and glucose. The Ni(OH) 2 /NiOOH modified electrodes in presence of the cationic polymer overlayers were well characterized by optical and electrochemical techniques. The modified electrodes showed excellent catalytic properties toward hydrogen peroxide oxidation and exhibited a wide linear range compared to the conventional and expensive Pt based catalysts used in H 2 O 2 based sensors. The superb electrocatalysis of hydrogen peroxide could be combined with the enzymatic oxidation of cholesterol and glucose showing, the feasibility of monitoring biological metabolites like glucose and cholesterol using the basic catalyst Ni(OH) 2 /NiOOH at physiological pH. Modified electrodes were highly stable and yielded reproducible results. Further the influence of graphene layer in decreasing the overpotential of the detection of H 2 O 2 and its effect on the biosensing of cholesterol and glucose was further investigated. The sensing protocol was validated in the analysis of blood sugar in serum samples.

Wide-Linear Range Cholesterol Detection Using Fe2O3 Nanoparticles Decorated ZnO Nanorods Based Electrolyte-Gated Transistor

“…The cholesterol EGT biosensor showed a wide-linear range up to 60 mM cholesterol concertation from the calibration curve, which is comparatively higher than previous reports (Table I). [34][35][36][37][38][39][40][41][42][43][44] We calculated the sensitivity (37.34 μA mM −1 cm −2 ) of the EGT biosensor from the calibration curve's slope (2.987 μA mM −1 ).…”

Electrochemical Biosensors for Whole Blood Analysis: Recent Progress, Challenges, and Future Perspectives

“…Hydrogen peroxide has been also explored as intermediate product for the purpose of analysis of other targeting analytes. Such examples include glucose, ,− lactate, secretory phospholipase group 2-IIA, cholesterol, etc. ,,,, Other types of sensors are reported to rely on the amplification of electrochemical signals via the reaction of HP, achieving a high sensitivity and specificity of targeted analytes. ,,− …”

“…Such examples include glucose, 23,281−289 lactate, 238 secretory phospholipase group 2-IIA, 290 cholesterol, etc. 208,211,214,215,291 Other types of sensors are reported to rely on the amplification of electrochemical signals via the reaction of HP, achieving a high sensitivity and specificity of targeted analytes. 206,278,292−302…”

Electrochemical Sensing of Ascorbic Acid, Hydrogen Peroxide and Glucose by Bimetallic (Fe, Ni)−CNTs Composite Modified Electrode

“…Similarly, glucose is the main energy source in living organisms and it is a very common fuel in biological system, especially used in muscles and brain [5]. In most organisms, from bacteria to humus, it provides energy through fermentation, aerobic respiration and anaerobic respiration [6] and approximately3.75 kilocalories of energy can be attained per gram with the aid of aerobic respiration [7].…”