An Overview on Electrochemical Determination of Cholesterol

Abstract

Cholesterol detection is of great significance in biomedical applications because it is a crucial biomarker for some diseases. It is the precursor of different biological compounds such as vitamin D, hormones, and bile acid, etc. The cholesterol level in blood correlated to various diseases such as hypolipoproteinaemia, septicaemia, malnutrition hypertension, anaemia, brain thrombosis and arteriosclerosis for instance its levels in the blood of more than 200 mg/dL, increase the risk of heart disease. It is also found in foods from animal origin such as milk, meat, cheese, egg and seafood. With respect to dietary reference value for cholesterol intake, most of food safety authorities recommended maximum intake 300 mg per day for adults. Consequently, cholesterol is considered as a critical indicator of clinical biochemistry and introducing new techniques for determination of it in biological samples and food is important. In this review, Principles, methods and recent developments in electrochemical cholesterol sensors are reviewed. Special attention is given to the discussion on some problems and bottlenecks in areas of enzymatic cholesterol sensing and new advances in non-enzymatic sensors.

A versatile reactive oxygen species‐responsive gels sensor for analysis of metabolic species

“…Cholesterol is a steroid ubiquitously present as a constituent in plasma membrane and acts as a precursor for bile acids, vitamin D and hormones etc. (Amiri & Arshi, 2020; Lee et al, 2018). As illustrated in Figure 2b cholesterol is oxidised to H 2 O 2 by cholesterol oxidase.…”

“…The sensitivity of cholesterol oxidase base sensor was 53% times higher than the enzyme‐free ROS sensor. The LOD for the cholesterol oxidase‐based ROS sensor was determined to be 0.12 ± 0.02 µg/ml, well below the normal ≤2000 μg/ml blood cholesterol and ≤than the normal levels in saliva (5–46 μg/ml) (Amiri & Arshi, 2020; Lee et al, 2018). The cholesterol oxidase‐loaded ROS sensor had a calibration sensitivity of 1.97 µF/µg ml −1 .…”

“…The cholesterol oxidase and lipoxygenase immobilised nanoferrogel ROS sensors were evaluated for their detection of cholesterol and unsaturated oils, respectively. As illustrated in Figure 2b, cholesterol oxidase oxidises cholesterol to H 2 O 2 , detectable by the nanoferrogel ROS sensor (Amiri & Arshi, 2020; Lee et al, 2018). The sensors were tested by first acquiring a blank cyclic voltammogram of a 50 µl of 0.1 M phosphate buffer (pH 7.0).…”

“…In addition, H 2 O 2 is a by‐product of many metabolic reactions involving physiologically relevant species such as glucose, choline, cholesterol, lactate etc. (Amiri & Arshi, 2020; Hossain & Park, 2017). Furthermore, H 2 O 2 is relevant as signalling molecule for bacterial and plant metabolism (Antunes & Brito, 2017; Duan et al, 2016; Fuller et al, 2017; Gambino & Cappitelli, 2017; Joelsson et al, 2007; Saxena et al, 2016).…”

“…Conventional amperometric devices for H 2 O 2 detection require Horseradish peroxidase enzyme, thus the sensors are unstable with short shelf life (Amiri & Arshi, 2020; Hossain & Park, 2017; Nguyen & Kasi, 2015). Similar to peroxidases, Prussian Blue ROS scavenging ability is associated with hydroxyl radicals affinity (Zhang, Hu, et al, 2016).…”