Different shades of cholesterol: Gold nanoparticles supported on MoS2 nanoribbons for enhanced colorimetric sensing of free cholesterol

Abstract

In the present study, we manifest that traditionally used gold nanoparticles when supported on molybdenum disulfide nanoribbons matrix (MoS2 NRs-Au NPs) show synergistically enhanced intrinsic peroxidase like catalytic activity and can catalyze the oxidation of 3,3',5,5' tetramethyl benzidine by H2O2 to produce a highly sensitive blue shade product depending on level of free cholesterol, when tested on complex system of human serum. Further the system attests appreciable kinetics, owing to Km value as low as 0.015mM and better loading capacity (Vmax=6.7×10-6Ms-1). Additionally, the proposed system is stable for weeks with ability to perform appreciably in wide pH (3-6) and temperature range (25-60°C). Utilizing this potential, the present work proposes a cholesterol detection color wheel which is used along with cost effective cholesterol detection strips fabricated out of proposed MoS2 NRs-Au NPs system for quick and reliable detection of free cholesterol using unaided eye. © 2015 Elsevier B.V.