One-step electrochemical detection of cholesterol in the presence of suitable K3Fe(CN)6/phosphate buffer mediator by an electrochemical approach.

One-step approach of cholesterol biosensor was fabricated onto smart micro-chips based on cholesterol oxidase (ChOx) co-immobilized thioglycolic acid self-assembled monolayer (TGA-SAM) for biomedical applications. The selective cholesterol biosensor was investigated with modified tiny micro-chip (Au/SAM/ChOx) by the facile and reliable cyclic voltammetric (CV) method in a K 3 Fe(CN) 6 /phosphate buffer (PB) system. The modified micro-chip displayed a large dynamic range (1.0 nmol L −1 to 1.0 mmol L −1 ), lower detection limit (~0.49 nmol L −1 , based on S / N ~3), higher sensitivity (~93.75 µA µmol L −2 cm −2 ), good linearity (correlation coefficient r 2 , 0.9995), lower sample volume (<50.0 μL), and good stability as well as reproducibility. The Au/TGA system was implemented for a facile and simple approach to the immobilization of ChOx onto micro-chip, which can offer analytical access to a large group of enzymes for a wide range of bio-molecule applications in health-care and biomedical fields. This integrated microchip provides a promising low-cost platform for the sensitive and rapid detection of biomolecules using miniatured samples. [ABSTRACT FROM AUTHOR]