Cholesterol biosensors: A review

Abstract

HIGHLIGHTSSerum cholesterol level plays important role in the diagnosis and treatment of various diseases e.g. hypothyroidism, nephrotic syndrome, diabetes and liver diseases.Cholesterol level upto 200mg/dL (healthy person), 200–239mg/dL (borderline high).Present review summarizes the principle of various biosensing methods for determination of cholesterol. ABSTRACT Cholesterol is the most important sterol synthesized by most of the human cells majorly in the liver. It is a necessary constituent of cell membranes, it acts as a precursor for the synthesis of steroid hormones, vitamin D, and bile acids. Cholesterol is transported in plasma primarily in the form of low‐density lipoproteins (LDL), the principal route for its removal from tissues to the liver is in high‐density lipoproteins (HDL), followed by excretion in the bile. Cholesterol level is less than 200mg/dL in healthy persons. 200 and 239mg/dL is considered borderline high and 240mg/dL and above is considered a biomarker for cardiovascular diseases, heart attack, strokes, peripheral arterial disease, type 2 diabetes and high blood pressure. Several methods are available for detection of cholesterol, among them, most are burdensome, time‐consuming, require sample pre‐treatment, high‐cost instrumental set‐up, and experienced personnel to operate. Biosensing approach overcomes these disadvantages, as these are highly specific, fast, easy, cost‐effective, and highly sensitive. The review describes the various cholesterol biosensors. Cholesterol biosensors work ideally within 1 to 300s, in pH range, 7.0–8.6, temperature 25–37°C and cholesterol concentration range, 0.000025–700mM, the detection limits being in the range, 0.000002–4mM, with working potential −0.05 to 0.65V. These biosensors measured cholesterol level in fruit juices, beverages, sera and urine samples and reused up to 200 times over a period of 15 to 50days, while stored dry at 4°C (Table 1). Future perspective for further improvement and commercialization of cholesterol biosensors are discussed. Table 1 A comparison table of various electrochemical biosensors for determination of cholesterol.