Molecularly imprinted polymeric microspheres for electrochemical sensing of cholesterol

Abstract

An electrochemical cholesterol sensor based on emulsion photo-polymerized methacrylic acid molecularly imprinted polymers (MIPs) microspheres modified screen-printed electrode (SPE) has been developed. Electrochemical quantitation of cholesterol concentration was performed by means Cyclic Voltammetry (CV) and Square Wave Voltammetry (SWV) technique by using redox couple of potassium ferricyanide [K3Fe(CN)6]. A decrement in the electrochemical CV and SWV signal indicated that the cholesterol molecules were bound to the microspheres’ cavities of the biomimetic MIPs sensor, and formed an electron transfer barrier to the redox species from electron transfer at the electrode surface. Under optimal conditions, the electrochemical MIPs microsensor could detect cholesterol concentration in the linear response range of 0.5 mg L-1 to 50.0 mg L-1 with a limit of detection (LOD) at 0.1 mg L-1. The MIPs microspheres-modified carbon SPE electrode providing good operational stability to cholesterol sensing of up to 11 days long.