Cerium (Ce) and antimony (Sb) codoped tin dioxide (SnO2) films (Ce:Sb:Sn=2:3:95 molar ratio) have been prepared on the surface of titanium (Ti) substrate by sol-gel method. A self-assembled layer (SAL) of dodecyl thiol with cholesterol was formed on the surface of Ce-Sb codoped SnO2films/Ti electrode. The SAL was then used with the cholesterol as the template forming the molecular imprinting layer. The extraction of cholesterol has resulted in formation of sites in the layer of dodecyl thiol which could have been used as channels for the ferro-ferric cyanide coupled redox reaction to quantify recombining cholesterol on the sites. This sensor prototype could detect cholesterol concentrations between 40 and 60 μM. X-ray diffraction (XRD) and scanning electron microscopy (SEM) have been used to analyze the structure and morphology of the samples.
Self assembled monolayer based liquid crystal biosensor for free cholesterol detection